Archive for the 'Modification' Category

08
Aug
18

Stylophones 6 – The Soviet Stylophone

With the help of a correspondent to my blog I was lucky enough to get hold of an early 80’s ‘Stylophone’ from the Soviet Union.

Entitled the ‘Gamma’, I’m told it was made in the city of Chernivtsi, a part of the Soviet Union now in western Ukraine.

Larger than a Dübreq Stylophone, it came in a neat plastic box measuring about 25x20x5cm.

Inside, the Gamma Stylophone itself has a 20-note keyboard at the front, a stylus – more complicated than a Dübreq Stylophone stylus – on a twin lead, a volume control on the left-hand side, and a speaker in the top left-hand corner.  A coloured label indicates the notes of the scale represented by each section of the keyboard.

There are also 3 strange slots above the keyboard, which are slightly wider than the keyboard and just deep enough to be accessed by the stylus.  This close up of the keyboard shows the middle of two of these slots:

The stylus, as mentioned above, is more complicated than the Dübreq Stylophone stylus in that it includes a combined press and slide switch.  It turned out that the press switch had to be pushed for the stylus to work; the slide switch turned the vibrato on or off.

Helpfully, my correspondent had cleaned the instrument before sending it, so there wasn’t a lot for me to do!  I opened the case – just 4 slot-headed screws underneath – and examined the insides.  The circuit board was attached to 4 mounts on the base; the speaker had 4 mounts on the front.

Turning the circuit board over, I could see the components and the layout.  Everything seemed neat and well made, with a good solid loudspeaker.

The components on the circuit board weren’t quite the same as their Western equivalents, but quite recognisable, nonetheless:

I removed a little more of the disintegrating foam – and replaced a speaker wire, which I had inadvertently detached – and then turned to the power cables.  The battery fittings had been removed, but I could see from the booklet which came with the instrument, that these had been designed for a pair of Soviet-style 4.5v batteries: my correspondent explained to me that these were similar to a group of three 1.5v batteries – not unlike the kind of thing we used to have inside cordless phones – but which were, in any case, now uncommon.

I just added a PP3 battery clip, similar to the type one would find in an old-style Dübreq Stylophone, which worked fine.  I hadn’t intended to ‘circuit-bend’ this device, but I pondered on adding an on/off switch, as there isn’t one in the original design.

I attached the battery and tried it out.  The push switch needed a bit of attention – a few squirts of contact cleaner helped – but all the notes sounded perfectly, and the vibrato turned on and off.  I wasn’t able to check that the notes were in tune, and there’s no fine tuning control, which you would find on a Dübreq Stylophone, but I’ll look into that later.

The booklet that came with the Gamma Stylophone was delightful – the paper and printing quality weren’t high, but the illustrations were beautiful and the colourful instructions on how to play the many songs were attractively set out.

Read the Gamma Stylophone Booklet.

I’m told that Chernivtsi is in the region of Bukovina, which lies partly in the Ukraine and partly in Romania, and that the costume of the dancer in the picture is from this region.

The serial number in the booklet and on the back of the instrument is ‘304’.  It is normal, apparently, for these instruments to have 6-figure serial numbers, so this could be a very early example.

There is no circuit diagram in the booklet, but this is said to be unusual in the Soviet era when it was common for these to be included.

Here’s a short video of me testing the Gamma Stylophone.  You can see from this clip how the stylus switches function – and also what the 3 extra slots are for!

Continue reading ‘Stylophones 6 – The Soviet Stylophone’

25
Feb
18

Dismantling a hard drive

Note that in the following post I’m describing taking a hard drive apart in order to reuse some of the parts, but have no intention of putting it back together, or making it work again as a hard drive!

This the 3.5″ hard drive I took apart as my first experiment:

Front & Back IMG_1515

I’m sorry the PCB side is rather blurry, but I was less interested in that than what was inside.

The tools required for the job were a small screwdriver set, from which I mostly used a Torx or ‘star’, which I think was size 8, and a very small Philips or crosshead for a couple of screws inside:

Tools IMG_1525

I also needed a large flat-bladed screwdriver, which I used two or three times.  If you’re going to do the same, you may find a few differences in the details – type and positioning of screws, differently shaped fittings, and so forth, but the principles should be the same.

I first removed the circuit board, and put that aside.  Turning it over, you can clearly see in the first picture the 6 screws round the edge of the ‘lid’ which needed removing.

Having taken these out, it seemed that the top was glued in place as well as screwed, so I went round with the large screwdriver, prying it open.  This almost freed it, but it was only after still experiencing considerable difficulty in getting it completely open that I realised there must be another screw somewhere in the middle, under the label.  I scraped away the label until I found it and took it out.  The arrow shows where it was.

Top IMG_1527

I was then able to take the lid right off and expose the inner workings – of which there aren’t actually that many.

Top removed Captioned IMG_1528

The picture shows the disk or disks, one on top of the other, like a stack of pancakes – except there are gaps between them, and the arm is actually several arms, one for each disk; the arm itself with the delicate heads on the end which read the data from the disks, and with its other end moving between two magnets (not visible at the moment); and finally a flexible plastic multi-way ‘cable’ which joins the arm – and some small circuitry on the arm – to a connector.  This would have poked through a gap in the case to connect to the circuit board  on the other side.

Later on, connections will have to made to some very, very tiny points on the arm, and it’s going to be a lot easier to trace these points back to the connector, so its important not to damage the plastic cable.  The connector could be poked out from the other side, once it two fixing screws had been removed.

The fitting obscuring the back end of the arm wasn’t – in this model of drive anyway – screwed in place, it was just slotted on some pins and just needed prising off.  I believe the magnets in hard drives are made of neodymium.  This is classed as a ‘rare earth’ (although it’s isn’t actually any rarer than, say, copper) and makes very strong magnets.  Just be a bit careful as you remove them, and think where you’re going to put them down as you can be surprised at how firmly they grab lighter metal objects.

This picture shows the top magnet fitting removed:

Top Magnet Out Captioned IMG_1529

Once the top magnet is off, it’s possible to move the arm out of the way and get the disks out.  This involves removing 6 screws around the centre (on top of the motor) and two screws at the side. the disks and the various fittings associated with them all come off in layers.  The disks – there were three of them in this drive, look very much like CD’s, with a large hole in the middle, except they’re made of metal.

I put the disks carefully to one side – I had an idea they might be good for chimes or cymbals – and focused on the arm.

With the top magnet out of the way, it was possible to see the so-called ‘voice’ coil’.  Two impossibly tiny wires connected the voice coil with the arm actuation circuitry, and to test that the arm was working I needed to attach a battery to these wires.

In the end these wires were just too small, so I traced them back through the plastic cable to the connector, where it was slightly easier to get at them.  Attaching the battery leads to the two points produced nothing at 4.5v, but at 9v there was a loud and satisfying clunk, which showed that the arm was working fine.

*

The procedure with the next disk I worked on, a smaller 2.5″ was exactly the same.  The top came off once I had removed the 6 visible screws and the 7th screw hidden under the label.  I needed a smaller Torx/star screwdriver – a size 5 or 6 – for this disk compared to the other one.

1_IMG_1555

This exposed the single disk and arm:

2_IMG_1557

A single screw in the middle of the motor housing allowed the disk to come out.

3_IMG_1558

Removing two screws freed the unit in the bottom right, which connected the arm with the circuit board on the other side.

4_IMG_1559

I prised off the top magnet (bottom left), just to make sure the construction was the same as the 3.5″ drive – which it was.

I replaced the magnet and tested the drive with a battery.  I’d already removed a plastic retainer on the right, by the heads at the end of the arm; I also had to remove the plastic piece which you can see on the left, which was restricting the arm’s movement.  However, once I had done this, applying 9v to the appropriate pins on the connector reliably operated the arm.

In fact, this smaller mechanism would also work with 4.5v, which was a useful discovery.  If parts of the circuitry which would operate it had to be quite low – say, 5v – it could be handy if the arm would also work at the same voltage.

*

So, I had verified that an arm from an inexpensive broken hard drive could operate as an electrically-operate striker, like a solenoid; that arms from both 3.5″ and 2.5″ drives would work; that the 3.5″ drive arm would operate at 9v; and the 2.5″ drive arm would operate at 4.5v.  It will be some time before I get round to the next part of this project, but the next thing will be to see how the arms could be set up to operate outside the hard drive housing.

15
Jan
18

The Blue Cow

Having just finished a couple of projects designed for automatic control via the Bigfoot sequencer, I was looking for a similar toy that could be played manually.

The Blue Cow seemed to be exactly the kind of thing I was looking for. which could be worked on with a combination of modification and circuit-bending.

There are buttons which make the sounds of a cow, cowbell, cat, dog and pig; two switches – the ducks’ beaks – which play a short musical sequence and light up the 6 LEDs; and three mechanical controls.  One, a snail which moves slowly across the cow’s back, makes no electronic sound, but there are two others which do: a rotating ball which makes the cowbell sound as it turns, and a rotating control with finger-holes, which moves the cow’s tail and plays a tune with a bell-like tone.

*

I opened the back of the device and took a close look at the PCB inside.

The first thing I noticed was an extra switch which hadn’t been used.  It had the word ‘sheep’ next to it, so I eagerly connected a pair of wires to it and, sure enough, a baa emerged.  So the first thing I did was add an extra switch on the front of the cow to produce this new sound.

*

After that I searched for the resistor which would affect the pitch of the sounds.  It took a while, but I found it, removed it from the board, and attached two wires in its place, running to a potentiometer so that the pitch could be varied.

In this view of the circuit board 1 indicates the previously unused switch, and 2 indicates the position of the pitch/timing resistor.  The wires now connected to these two sections are on the underside of the board.

It took a little experimentation to find the correct value for the potentiometer, to ensure sufficient pitch variation, but not to increase or decrease the resistance so much that the device crashed.  This is the normal thing when replacing a timing resistor.  In this case, a 250k potentiometer was the best value, with a 100k trimmer to adjust the minimum resistance.

The potentiometer went on the front of the cow.

*

I unscrewed  the sections behind the 4 main sound buttons, and checked the additional circuit boards which were connected to the main board by a series of red wires.  There were 14 of these these wires, which went directly to the sound-producing chip.

Some of these wires went to LEDs beneath the buttons, so  I tested the others by connecting them in pairs, and found various combinations which would produce almost all available the sounds, including the newly-discovered sheep.  If I included one of the connections of the switches under the ducks’ beaks, all the sounds were available, and I began thinking of extra ways to access them.

First of all I added four tilt switches, so different sounds would be produced as the device was moved around.  These were a simple and cheap type – about 10p each – but very effective.  Constructed in a small can with two legs, not unlike an electrolytic capacitor in appearance, an internal connection is made when the can is tipped from horizontal to vertical.

I glued the switches inside, left, right, top and bottom, with a different sound connected to each.  The arrows in the following picture indicate two of the switches in situ.

*

One awkward thing about the circuit – especially with the tilt switches in place – was that there was no on/off switch: the power was on – and the device ready to make noises – as soon as batteries were inserted.

So, I decided to add one.  I found a nice one, described as an SPST illuminated rocker:

The odd thing about it, as an SPST, is that it has 3 contacts.  It took me some time to work out, but its normal function is to switch +v from one outside contact to the centre; the other outside contact – not connected to the switch – is for a 0v connection to the internal LED.  In this case, the power lead from the batteries connects to the ‘off’ side of the switch, the lead to the circuit board connects to the centre, and the 0v lead connects to the ‘on’ side of the switch.  In this way, when the switch is turned to the ‘on’ position, power is connected to the circuit board and the switch lights up – very attractive!

I liked these switches so much, I bought several of them at about 30p each.  They were labelled as suitable for 12v – their origin is for use in the automotive industry – but lit up fine from the Blue Cow’s 4.5v.

There’s quite  variety of illuminated switches available, all of which would beautify a project where a +V switch was required.  There were also square ones:

although I always find these more difficult to mount than round ones.  The one on the right looks interesting, as it’s a centre off with a latching switch one way and a momentary switch the other.

One UK outlet has a whole variety of these, including toggle switches, push switches and pull switches:

At this time I also added a small SPDT switch to change the output from the small internal speaker to 4mm external speaker sockets or to an audio out socket.

In the  following picture 1 = the internal/external speaker select switch; 2 = the speaker select switch inside; 3 = the external speaker sockets; 4 = the audio out socket.

*

Here’s a short demo of the Blue Cow.  In this case it was connected to an external speaker and the sound recorded via microphones.

12
Oct
17

The Carousel Keyboard

‘Carousel’ was just the brand name of this toy keyboard, it didn’t unfortunately look like a carousel . . .

. . . but having just finished the Animal Band and The Telephone, I wanted, while it was in my mind, to work on another device that could be controlled by the Bigfoot, only this time with a full two octave span, the ability to play a variety of different scales, and be tuned to play these scales in any key.

I opened up the Carousel, and it looked as though it would fit the bill.  The chip on which it was based was securely hidden under a black blob, but there were sufficient additional components to make me think a few simple hacks would be possible.

First of all, I wanted to check the instrument’s ability to be tuned.  I inserted batteries, switched on and began testing the circuit using the traditional wetted finger method – that is, starting the instrument playing one of its demo tunes and applying a wetted fingertip to different resistors on the board.

After a short test, I found the resistor that controlled the instrument’s pitch and timing.  It was a tiny SMD (surface-mounted) component, just 3 or 4 millimetres long, so was easily – though carefully – removed.  Its value – again, printed on the circuit board – was 300k, so after it was removed I replaced it with a 1M potentiometer, to increase the range of notes the instrument could produce.  The spot from which the resistor was taken is arrowed on this photograph, and the two leads going to the potentiometer can be seen:

(Also visible in the background are the wires connected to the PCB tracks required to trigger the notes).

I experimented with the resistance and found that the minimum the device would accept without crashing was about 200k, so I added an extra couple of 100k resistors before the 1M potentiometer, and found that a considerable variation in the pitch was achievable.

*

Early on in this process I disconnected the internal speaker, which was quite terrible, and added my standard 4mm banana sockets for attaching an external speaker.  The sound was 100% improved, and experimenting became a great deal more pleasurable.

Just beneath the speaker sockets a switch can be seen, which I connected up to allow the internal speaker to be selected, if an external speaker wasn’t available.

I later added an audio out socket, to allow the Carousel Keyboard to be played through the Taurus amplifier.  At first this didn’t work at all – virtually no sound came out, even though it would work with the internal or external speakers.  But I realised the output of the circuit needed a load in place of the speaker, so I put a 10 ohm resistor between the audio out and ground pins on the audio out socket, and after that it worked fine with an external amplifier.

*

I was saved from having to do the job I had performed on the Animal Band and The Telephone, working out which PCB tracks needed to be connected to produce the different notes: to my surprise, this was printed on the back of the circuit board.

There appeared to be an 8 x 5 matrix, so connections were made to the relevant PCB tracks, ready to be brought out to a new board.

*

The intention was to be able to control the keyboard with the Bigfoot sequencer, so I added a 5-pin DIN socket and 4050 buffer, as usual, ready to accept the Bigfoot’s 4-bit binary input.  This is in the form A B C D, where A is the last – rightmost – bit in the binary number, and D is the leftmost.  A is sometimes referred to as the LSB (Least Significant Bit) and D the MSB (Most Significant Bit).

The binary number 0010, for example (the number 2) would mean that D was 0, C was 0, B was 1 and A was 0; in practical terms this means that input D was 0v, C was 0v, B was +v and A was 0v.

I needed one of the inputs (D) to be inverted – i.e. if the input was 0v, I needed +v, and if the input was +v, I needed 0v – so with the 4050 was a 40106 inverter, with sections which change 0v to +v and +v to 0v.  There was very little space inside the keyboard case, so the board with the 4050 and 40106 was tucked under the output socket.  (This was before I added the 10 ohm resistor on the socket).

The circuit of the input section was like this:

There are 6 buffers in the 4050 chip; 4 of these are used (marked A B C D) and the inputs of the other two are connected to ground.  Likewise, there are 6 inverters in the 40106; 1 of these is used and the inputs of the other 5 are connected to ground.  Unused inputs on CMOS chips should normally be grounded like this to ensure correct operation.

Normally, I would use a 4067 to cover the two octaves produced by the Bigfoot – as in the Animal Band and The Telephone – but in this case that wouldn’t work.  The 4067 is essentially a 16-way switch with a single pole; in this case there were 4 different ‘poles’ to which connections needed to be made, since the notes are produced by a matrix.

Using four 4067’s would be perfectly possible, but unnecessarily expensive – each one costs between 30 and 50p, and is physically quite large, being in 24 pin wide format.  As there would only be 4 or 5 connections to each pole, it would be more effective in terms of cost and space in this circuit to use 4051’s.  The 4051 is an 8 pole switch which works in more or less exactly the same way as the 4067, but is physically smaller  – and costs less than 15p!

An important difference between the 4051 and the 4067 – related to the number of outputs – is that the 4067 requires a 4-bit binary input (16 numbers, from 0000 to 1111), but the 4051 only a 3-bit (8 numbers from 000 to 111).  This means that a different way must be found with the 4051’s to ensure that outputs for the first 8 numbers are separate from the outputs for the second 8 numbers.

This can be done by using the Enable/Inhibit pins of the 4051’s.  Each 4051 – just like the 4067, in fact – has an Enable/Inhibit pin: if this pin is at 0v, the chip will work, and convert its binary inputs into individual outputs; if the pin is at +v, it won’t work.

So, the first 3 inputs from the Bigfoot binary input socket, A B & C, are passed on to the 4051’s in the next part of the circuit, but the 4th input, D, is not.  Instead, the 4th digit is used to turn pairs of the 4051’s off and on via their Enable/Inhibit pins.

4051’s 1 & 2 output the lower 8 numbers (0000 to 0111), so as long as the 4th, leftmost, digit is ‘0’, these two 4051’s are enabled.  0v at the Enable/Inhibit pin achieves this.

4051’s 3 & 4 output the higher 8 numbers (1000 to 1111), so if the 4th digit is ‘1’, an inverted signal from the 40106 sends 0v to enable these two.

The circuit to convert the binary input to separate outputs looks like this. (The 40106 gate is repeated from the diagram of the input circuit):

The lower 8 notes are divided between the top two 4051’s in the diagram, which work together with no overlap in notes, and the higher 8 notes are divided similarly between the bottom two, according to which common pin they must connect to.  The pin connections are named in the diagram as they appear printed on the keyboard’s main PCB: the 4 common pins are connected to tracks named BP10, BP11, BP12 and BP13.

The reason there are many more than 16 output pins shown is connected with the principle of the Bigfoot sequencer.  The idea is that the sequencer outputs the notes of a scale – do, re, mi, fa, so, la, ti, do – but the exact scale – major, minor, melodic, harmonic, etc. – is determined by switches on the receiving instrument.  Normally there would be 5 double pole switches, but due to the configuration of the pins in the Carousel keyboard, one of the switches (SW2) needs to have 3 poles.

*

As with other of my designs like this, there wasn’t a lot of circuitry as such – just a lot of interconnection between the chips.  After soldering the dozens of wires needed to link the 4051’s with the switches and the Carousel keyboard’s PCB, the inside of the instrument looked like this:

There was just enough room for the new circuit board with the four 4051’s on it.

The Chessboard Keyboard proved very useful in checking that everything was working properly – one wrong note revealed a connection error on one of the switches! – and the 4 LEDs were a good double check that the binary input was being interpreted correctly.

*

Although the pitch control potentiometer worked well, I decided there was a need to be more precise about the pitch, which would effectively set the key the instrument would be playing in when controlled by Bigfoot.  So, as I had done earlier with The Telephone  – referred to above – I added a switch to change between the potentiometer and a 12-way switch.

Between each of the output pins of the switch, I inserted a 100k trimmer – with an extra 100k trimmer before pin 1 – so that the pitch of the instrument could be set to any one of the 12 steps in the octave.

In The Telephone I used ordinary single-turn trimmers, but I though it would be a good test to see if multi-turn trimmers would be as good – that is, as accurate in establishing the pitch, remaining in pitch, and not taking up too much space in the cramped enclosure.

The type I chose looked like this:

Buying 20 at a time enabled me to get them at a reasonable price – about 8p each, although this was probably twice as much the single-turn trimmers I had used in The Telephone.  They were also much more than twice as big.

However, I soldered them all in place and set about adjusting the pitches.

In this instance, I didn’t really find a big advantage in using the multi-turn trimmers.  I was tuning the pitches by ear – maybe I was able to be more accurate than with the single-turn trimmers, maybe not.  It took longer to tune each note, of course, because of the number of extra turns required.

I would have been glad if the potentiometer/trimmer arrangement had been a bit smaller, but I found space on the right-hand side of the keyboard to fit it in with the potentiometer and the other switch.  This picture shows 1 – the 12-way switch with trimmers, 2- the 1M potentiometer, and 3 – the SPDT switch which allows either the 12-way switch or the potentiometer to be selected.

I chose two knobs which fitted the space available on the top surface, drilled holes and fixed them in place.

*

That was everything I planned to do with the Carousel keyboard for now, so I carefully closed up the case and screwed it back together.  I had to cut some rectangular holes in the base to make room for the 5 switches, but surprisingly everything else fitted in.

 

23
Sep
17

The Alien Choir

The Alien Choir wasn’t a device I particularly wanted to circuit bend- the alien voices it makes are fine as they are!  – but I wanted to do a couple of things to make is easier and better to use.

The Alien Choir is one of the ‘Finger Beats’ series.  These are recognisable by their distinctive design, and are all operated in a similar way, using light finger pressure in certain places on a colourful illustration on the front.

I don’t have an instruction book with mine, so it’s not clear that all of its functions are working – in particular, recording samples with the built-in microphone – but it makes 8 excellent alien voice sounds.  The volume of the sounds can be turned up or down with the ‘+’ and ‘-‘ buttons on the left-hand side.

*

First of all, although 3v isn’t an odd or unusual value, I decided to add a socket and dc converter to allow the device to be powered by a mains adapter or larger – e.g. 9v – battery.  To this end I also added a small square of velcro to the back, as I had with other instruments before, to allow one of my 9v battery holders to be attached.

The dc converter was a small and inexpensive (less than 50p) module, which didn’t need any additional components, just an input voltage from 20v down to about 1v higher than the desired output voltage.  The output voltage is set by means of a small trimmer on the board.

In this case I found that the required voltage, as measured on my multimeter, needed to be a little lower (about half a volt lower, in fact) than the anticipated 3v in order for the circuit to work smoothly.  I don’t know if this is something specific to the Alien Choir, a difficulty in measuring the voltage precisely, or what.

Inside the device, I added a switch to choose between the battery or the external socket.  In the following picture  1 indicates the socket, 2 the dc converter and 3 the switch.

The device has a 3.5mm audio out socket (and an audio in, in fact, as can be seen in the lower right-hand corner of the picture above), but I decided to add banana sockets for connection to one of my external speakers.  This always produces a much better sound than the small built-in speakers these devices are fitted with.

The small switch on the right selects either the internal or external speaker.

I hope this will be a useful – and certainly attractive – addition to the ‘Outer Space’ section of my instrument collection.

06
Sep
17

The Animal Band & The Telephone

This project came about as I was looking through my collection of electronic toys for additional devices that could be controlled by the Bigfoot sequencer or the Chessboard keyboard.

I don’t know if ‘Animal Band’ and ‘Telephone’ are the correct names for these toys, but they are sufficiently descriptive to identify them amongst my various devices.

Both the Bigfoot and the Chessboard encode the 15 pitches (2 octaves) they can produce into 4-bit binary numbers so that they can use standard 5-pin DIN connecting leads – the same as MIDI leads – rather than more complex multi-way connectors to control sound-making instruments.

I came across two devices, which were rather limited in that they played only a one octave scale; but it was the same scale – B major – and one of them had not only small animal musicians who moved as the notes were sounded, but was also capable of playing a scale with various animal noises.  For some reason, this scale turned out to be A major, but this was only a minor inconvenience.

The additional electronics required would be similar to those in The StyloSound, the main thing being a circuit to convert the binary number input from the Bigfoot or The Chessboard to the individual notes of the scale.  Both the devices would need one of these.

The basic circuit I use looks like this:

Receive circuit 3

At the beginning, the input passes through a non-inverting buffer.  (There are 6 connections from the input to the buffer in case a later plan for operation via MIDI is implemented, which is designed to use 6 bits.  For the time being, only the first 4 are being used, the other 2 remaining unconnected).

The purpose of the buffer is to reduce the incoming signal level (which, from both the Bigfoot and the Chessboard, is at 9v) to 4.5v, the voltage of the Animal Band.  The 4050, unusually, is able to deal with an input signal which is higher than its supply voltage, which makes it ideal for this purpose.

When functioning, the 4067 will interpret the 4-bit binary input on pins 11, 12, 13 and 14 as a decimal number from 0 (0000) to 15 (1111) and act as a switch, connecting pin 1, the Common, to one of its 16 outputs on pins 2-9 and 16-23.  Each of the 4 binary inputs is held at 0v by 100k resistors, interpreted as a ‘0’ by the 4067, so a +v pulse on one or more of the inputs pulls them high, acting as a ‘1’

To avoid silences – Bigfoot produces 16 notes, the Animal Band produces only 8 – the output pins for notes 9 – 15 are connected to the pins for notes 2 – 8.

Pin 15 is brought out to an SPDT switch.  When connected to +v, the 4067 is turned off; when connected to 0v, it is turned on.  The Telephone would have a similar switch.  In this way either instrument can be set to work or not work without disconnecting the power.

*

To find exactly where to connect the Common and output pins of the 4067 I needed to search inside and test different points on the printed circuit board.

I removed the top:

Animal Band top

and examined the inside:

Animal Band inside marked

The important sections are marked.  (Normally the LEDs are pointing upwards, but I was in the process of examining them when I took this picture and had unscrewed the circuit board on which they are mounted).  In the centre of the device you can also see the rod by which the stepper motor moves the figures of the animal band when notes are sounded, and at the bottom the actuators which are pressed by the keys.

The first thing I did after opening the case was to give the actuators a clean.  They are the typical type – like computer keyboards or game controllers – which, when pressed, connect together two narrow tracks on the PCB.  If dust and dirt get inside them, they can operate erratically.

This is a typical example (from The Telephone) of the PCB tracks underneath a button:

Button pad

Apart from cleaning these small PCB tracks, I gave the carbon or graphite blocks which make the connection a light scrape to make sure their surfaces were also free of dirt and dust.

The important connections inside the Animal Band seemed to be grouped together in the bottom left-hand corner, so these are the connections I looked at first.  After testing them, I could see that the following connections needed to be made:

Animal Band PCB

The point marked ‘Common’ needed to be connected to pin 1 of the 4067, and the 8 notes to first 8 output connections on the 4067.  (Actually, output 1, pin 8, in the Bigfoot system is not connected, so the unit is silent on receipt of 0000.  The first note sounded is 0001, so the outputs used are 2-9, starting with pin 7).

In the Bigfoot system, an instrument which can sound all 12 notes  in an octave would have switches to raise or lower some notes of the scale (the 2nd, 3rd, 4th, 6th and 7th notes), but the Animal Band and the Telephone are fixed to play a major scale, so these switches aren’t needed.

*

Finally, there needed to be a circuit to connect the Animal Band and The Telephone.  This would have to combine the input from Bigfoot, the Chessboard (or other 4-bit binary input) and send this in binary form to The Telephone.

This consisted only of inputs from two DIN sockets, entering via diodes, and passing through a second 4050 buffer.

The circuit board ended up looking like this, as I had originally planned to include a further circuit which would convert 16 individual inputs to a 4-bit binary output (as used in the Chessboard):

circuitboard

The large 24 pin chip at the bottom left is the 4067; the two chips above are the input and output 4050 buffers; the other 3 chips are two 4532’s and a 4071 for the unused binary-converting ‘Send’ circuit.  The diodes in the bottom right are for the inputs from Bigfoot and the Chessboard.

The board was designed to fit into the rear section of the Animal Band, behind the ‘organ pipe’ section with the LEDs in it.  I added 6 extra LEDs here, connected to the 6 outputs of the 4050 input buffer.

Most of the connections – including the 6 new LEDs – can be seen in this view of the inside, just before putting the case back together.

IMG_0947-2

This picture shows 3 of the new sockets and switches.  1 = the 5-pin DIN Out socket; 2 = the 4067 Enable/Inhibit switch; 3 = the audio out socket.  When a 3.5mm plug is inserted into the socket, the speaker connection is cut out.

IMG_0950-2

*

The Telephone needed a similar circuit.  The 4067 is one of my favourite chips, and I’ve been using it for some years, but recently, it seems , the Arduino hobbyists have started to use it, as there is now a reasonably-priced breakout board available, using an SMD version of the chip.  This looked like a real time-saver for me, so I bought a stack of them – at a cost of about 70p each – and The Telephone was my first chance to use one.

4067-Breakout-BoardAs can be seen, the 16 outputs are brought out on the left-hand side of the board, and on the right-hand side are ‘SIG’, which is the Common output on pin 1; the 4 binary inputs S0-S3; ‘EN’, the Enable or Inhibit pin; +v and Ground.

I couldn’t use this breakout board in every situation: the information with it said the maximum voltage should be no more than 7v – elsewhere I have even seen 6v.  I think the intention is that it would be used with 5v, like the Arduino, but in any event the 4.5v I was planning to use with the Animal Band and Telephone would be well within the limits.

Inside, The Telephone looked like this:

Telephone inside

The main circuit board inside The Telephone sits under the 12 buttons of the keypad.  It looked as though the important connections were down the right-hand side of the board, so, tracing the tracks, it was possible to work out which ones needed to be connected to produce each of the notes The Telephone was capable of.

Track 8 was the ‘Common’.  This track needed to be connected to one of 8 of the other tracks to produce the notes of the scale.  I identified which 8 tracks these were and connected these, plus the Common, to the 4067.  As with the Animal Band I connected outputs 9 – 15 to outputs 2 -8 to make sure The Telephone would be constantly sounding – except when in receipt of a 0000 input.

According to the circuit diagram of the module, it appeared that the Inhibit or Enable pin  was tied to Ground with a 10k resistor, so the unit would automatically be working when the power was switched on. 4067 breakout board schematicThis meant that only a SPST switch would be required to connect the pin to +v if it was necessary to stop it functioning.

The telephone was a less complicated unit than the Animal Band, so I just needed to connect the 4067 module to the input via a 4050 buffer, for which I just used a 16-pin i.c. socket, rather than a piece of veroboard:

Also visible in this picture are the four 100k resistors connecting the inputs of the 4050 to ground, and the audio out socket, which cuts out the internal speaker when a 3.5mm mono plug is inserted.

The outputs of the module were connected to the appropriate points on the Telephone PCB:

The only other thing to add was a switch attached to the enable/inhibit pin of the 4067 to allow the unit to be switched off without removing the power.  As mentioned above, the enable/inhibit was attached to ground internally in the module, so the switch just required a connection to +v, which would stop the 4067 from functioning.

This switch can be seen on the front left of this view of the outside of the finished unit:

On the rear can be seen the audio out (top) and 5-pin DIN (bottom) which can accept input from the Bigfoot sequencer, or a device compatible with the Bigfoot 4-bit binary note system (e.g. the Chessboard keyboard).

*

Having reassembled everything, it was time to check the devices in operation with the Bigfoot and the Chessboard, plugging them together with standard 5-pin DIN (or MIDI) cables, like this:

Everything seemed to work as expected, and the two units played in unison – or individually if one or other of the enable/inhibit switches were turned off – when operated either by the Bigfoot or the Chessboard.

Click here for a short film of the set-up taken on my iPhone.

[Edit: this article describes further modification to the Telephone]

 

26
May
16

Stylophones 5 – The Melophone

There are a number of different instruments called the ‘Melophone’ or ‘Mellophone’.  The one on the left in the picture below (by Kc8dis at the English language Wikipedia) is a brass instrument used in marching bands and the one on the right is ‘a cross between a guitar and a harmonium’, according to the Squeezytunes blog (at http://squeezyboy.blogs.com/squeezytunes/2008/02/melophone.html, from which the pictures came).

Mel(l)ophones

However, this Melophone which I recently acquired, is clearly a type of Stylophone – and a very stylish type of Stylophone at that!

Melophone2

Melophone1

I had never heard of this Melophone before, and found only a single reference to it on the internet.  A glance at the accompanying booklet – which, as you will see below, follows exactly the same style and format as the booklet from a 1960s/70s Stylophone – shows that it was not written by a native English speaker.  The company that manufactured it is (according to this website: http://www.pewc.com.tw/eng/) or was (according to this Wikipedia entry: https://en.wikipedia.org/wiki/Taiwan_Mobile) founded in Taiwan in the 1950s and acquired the name ‘Pacific Electric Wire and Cable Company’ on December 30th 1957.

The company would, therefore, have been in place to manufacture the Stylophone after its invention in 1967.  It looks as though it may have done so for some years as the picture on the box shows a Melophone with the early Stylophone keyboard with the black non-playing sections; just as the Stylophone was updated with a new keyboard, so it seems was the Melophone.

Box

The flap has a sticker on it showing the colour as yellow, which this one is; but other colours were presumably available.

It is, incidentally, not ‘Colour’, but ‘Color’, which may be an indication of the market it was intended for: Asia or America.  There would be no reason why it should not be intended for the UK, as the legend ‘Made in Taiwan’ was commonly seen during that period – except that genuine, British-made Stylophones were available over here, and Dübreq would surely not want to allow or encourage competition.

*

The similarities with the Stylophone – its appearance as well as its booklet – are striking: particularly the distinctively-shaped keyboard with its recess above to hold the stylus.

Stylus01

As can be seen  in the above photograph, the size and method of connection to the stylus are also the same as the Stylophone, and a detailed comparison of the yellow Melophone stylus with a black Stylophone stylus, shows that their dimensions are more or less identical:

Stylus02

Nevertheless, there are significant differences – aside, of course, from its handsome ‘Grand Piano’ shape!

First of all, although apparently identical, the Melophone keyboard is longer.  With a standard Stylophone on top, this can be clearly seen:

Keyboards

There are 2 extra notes at the bottom end of the keyboard, G and G#, and 1 extra note at the top, F – that is, 23 notes in total, as opposed to the Stylophone’s 20.

You can also see in the above photograph that the Melophone lacks the traditional Power and Vibrato switches at the left-hand end of the keyboard.  Instead, the Power On/Off switch is incorporated into a volume control on the top of the Melophone, to the left:

On_Off_Volume

The Vibrato switch is found on the left side, together with a control the standard Stylophone never had – an Octave-change switch!

Side

Using this switch, the range of the Melophone can be extended by another 12 notes, giving the instrument an exceptionally wide range.

Turning the instrument over reveals the battery compartment – like the original Stylophone, the Melophone requires a 9v PP3 battery – and the three screws which need to be undone to access the inside.

Back

The circuit board inside is quite different from the standard Stylophone – and so is the circuit itself: no fewer than 6 transistors can be identified in the following pictures (These are 1 x ED1402A, 3 x ED1402D, 1 x ED1402E and 1 x ED1602E, which are all NPN General Purpose transistors – except the 1602E, which is a PNP):

Inside1

Inside3

Inside4

Inside2

It has no tuning control like the standard Stylophone; I wonder if the top has been removed from one of the potentiometers in the first internal picture in order to make some pitch adjustment.

*

Comparing the Melophone Booklet with a typical Stylophone booklet of the period, the close similarity is evident:

Two CoversRead the Melophone Booklet

Even the two pieces of music at the back of the booklet are the same: ‘Silent Night’ in the key of Bb and ‘The Londonderry Air’ in the key of C, although references to ‘Stylophone’ or ‘Dübreq’ are noticeably absent.

*

One website (http://www.miniorgan.com/lib/view.php?miniorgan=80&view=E&srch=&srch_type=&sortby=&output=14) pictures and describes as ‘another very cheap STYLOPHONE clone’ an obvious copy (which they date to 1976 – the year after production of the original Stylophone ceased, according to the Stylophone Collectors Information Site  at http://www.stylophone.ws/index.html).  ‘Sounds poor and very poor plastic’, they say; but this Grand Piano Melophone seems like a step up from that, in sound and construction.

Here’s a brief example of the tones made by the Pacific Melophone:

Sufficiently Stylophone-like, I’m sure you’ll agree!  The two low notes beneath the Stylophone’s normal lowest note don’t come out too well, though.  I’ll have to see if something can be done about that.

Describing a Hong Kong made Stylophone, the Stylophone Collectors Information Site says ‘Problems were experienced by the Dübreq company regarding patent infringments, but licences were apparently also granted, so it is very difficult to categorise this particular model.’  Perhaps the same can be said for the Melophone: it definitely isn’t a Stylophone, but it seems to me reasonably built and with some very close similarities – was it somehow produced under licence, or just a clever copy?  If anyone has any further information, please let me know.

13
Mar
15

Guitar FXBOX – Part 2, the hardware

In my previous post on the FXBOX, I described a series of PureData patches used for guitar effects, and the need for a Foot Controller to operate it.

I happened to have a suitable case for this project – the remains of a previous mixer project which was never entirely finished. It was a large console-style case, about 18″ square, which I had already drilled with about 80 or 90 holes. The holes were too close together for all of them to be foot controller buttons, but about half of them could be used.

Outside of box DSCF0003

There were to be 4 sections to the controller, which would be: 1. Audio in/out and Audio to USB; 2. Audio to MIDI and MIDI to USB; 3. Keyboard Letters and Numbers, output via USB; and 4. Also via USB, Buttons and Potentiometers from a game controller.

*

1. AUDIO

The audio section was slightly more complicated than it might have been, as I’ve been using a twin-necked (6 and 12-string) guitar, and at some point intend to separate the output of the two sets of pickups.  For this reason, I added two audio input channels to the Controller.

The system basically works so that it can accept inputs either via a 6.35mm stereo socket or separate 6.35mm mono sockets, and can be routed either to a 6.35mm or 3.5mm stereo output, or two 6.35mm mono outputs. Each channel has a separate mono Send and Return, and there is stereo Send and Return covering both channels.

Audio DSCF0012

The 3.5mm output was included simply because this is the normal type of audio input socket on a laptop – which I was using to run Pure Data – and this would remove the need for a 6.35mm to 3.5mm adapter. Internally, there are connections to a Sonuus G2M Audio-to-MIDI converter – described in the next section – and an Audio-to-USB converter.

I took a chance on a cheap Audio-to-USB converter. I tried a few of the very cheapest type (99p on eBay), which worked OK, but I experienced too much latency, and these can only be used when the delay between playing and sounding isn’t important – on automatic or aleatory devices, for example. In this case, the next cheapest type (£2) seemed to work fine.

audio_usb

The intention of the Controller was that all four elements (the Audio to USB , the MIDI to USB, the keyboard numbers and letters, and the gamepad controls) would all be capable of output via a single USB socket. To accomplish this, I added an extremely reasonably priced (£3.95) 7-input USB hub. Given the number of items it would need to cope with, I got a powered one, which came with a 2-amp 5v mains adapter.

The inside of the box was going to be a bit like an enclosed pedalboard, and I simply velcroed this unit in position inside the case.

7 port hub

The hub was connected to a double USB socket unit – the type that would be fitted on a PC – with one socket connected to the type B output socket on the hub, the other one serving as an extra external input.

*

2. MIDI/USB

I added the MIDI section for two reasons: the first was that although MIDI implementation wasn’t really the point of this Controller, it could, I thought, come in handy for later applications, and be a convenient place to house my Sonuus G2M – a monophonic guitar-to-midi converter. The G2M, like the USB hub, was velcroed in place and linked up via internally-connected plugs.

G2M 27589983

Secondly, I’d successfully used a very cheap MIDI-to-USB converter in a previous project (‘A new use for USB keyboards‘), and decided for £3 or £4 that one could be included here. In this case, I didn’t even remove the outer casing as I had done the previous time, but simply shortened the IN, OUT and USB leads to fit and velcroed the unit to the inside of the case.

MIDI Inside box 1 DSCF0001

Audio and MIDI inputs would normally be via internal connections, but I added two 5-pin DIN sockets to the outside of the case. The first was for MIDI Out; the second, via a DPDT toggle switch, allowed input to the converter to be internal or external in case I wanted to connect a MIDI instrument or controller, such as my Behringer FCB1010, use another audio-to-MIDI converter, or decided not to use the G2M inside the case.

MIDI DSCF0012

*

3. LETTERS & NUMBERS

I had worked out for the previous project referred to above how to use the PCB from a defunct Apple keyboard as a means of outputting ASCII codes. The [key] function of Pure Data can be made to interpret and take action on these in any way required. I wanted to include this feature to help in using my looping program, Jesse Chappell’s Sooper Looper.

sshot6

As well as being controllable via MIDI, many of the Sooper Looper functions are controllable by input from the computer keyboard.  I wanted to include a simple system which would output some of the keyboard letters required to record, overdub, reverse and so on.

A 10×4 matrix would output all the letters in the alphabet, and the numbers 0-9, so I could put up to 40 buttons on the Controller (including a couple which represented punctuation marks), but I wouldn’t need anything like 40 buttons for this application.

I started confidently, as before, disassembled one of my collection of broken keyboards and took out the PCB.  It was very similar to the one I had used before: very wide, and with two USB input sockets on the ends – but it was a completely different make! So, I plugged the USB out cable into the computer, got the crocodile clips out, started up Open Office and began touching the matrix points together to see what letters came out – it had an entirely different layout from the one I’d used before!

However, after a certain amount of testing, it became clear that the matrix lines were essentially the same, but just in a different order on the board, which meant I could still get the 40 letters and numbers I wanted, and the pinouts on the sockets I planned to use (15 pin DIN HD) would still be compatible with the unit I had previously built.

In fact, it didn’t really matter about compatibility, as this would – at least as initially conceived – be a self-contained Controller unit, but I wanted to keep things consistent across my range of devices, and perhaps at a later date allow for an alternative or supplementary control unit to be connected to the Foot Controller.

I carefully connected the appropriate pins of the matrix to a ‘break out’ board, to which I connected a 15-way PCB header.

Apple PCB DSCF0004

This would make it a relatively simple job to connect buttons later.

*

4. GAME CONTROLLER

Again, I had used a game controller before, for the Theresynth/Cybersynth project, using the PureData [hid] function; but this time I needed to be more ambitious and use the joystick potentiometers as well as the buttons.

Of course, there are companies which produce USB controller modules, mainly for arcade controller enthusiasts, for example Ultimarc: http://www.ultimarc.com, and GroovyGameGear: http://groovygamegear.com.  The best value seemed to be the ZD (Zero Delay) Arcade controller, which is readily available on eBay.

Arcade Controller

I bought a couple of these two years ago at £8 each, but they seem to be even cheaper nowadays.

Good though they are, however, these units are limited to 12 buttons and two potentiometers.  Game controllers tend to have quite a large number of buttons – especially if you include the hatswitch buttons – and potentiometers on a single circuit board.

I needed 18 buttons, so I decided to use a game controller board for this part of the project.

There are a number of explanatory articles on the internet, such as this one: http://kevinreems.com/WorkShop/Joysticks//, and a lot of valuable information on this forum: http://forum.arcadecontrols.com/, as well as a few videos on YouTube. I like this one, which, although not captioned in English, is nicely visual: http://www.youtube.com/watch?v=9Y6ZqgT4Uk0.

Even Nic Collins’ classic book Handmade Electronic Music [http://www.nicolascollins.com/handmade.htm] has a chapter on the subject.

There are many different makes and models of gamepad, and one thing I’ve learned is that they’re all different – or liable to be different – in their electrical connections, so a certain amount of cautious experimentation is required to find out, for example, whether button connections are made to ground or some other voltage value in the circuit; if they’re arranged in a matrix; or if there’s a mixture of different systems. Sometimes this can readily be determined by looking closely at the circuit board and following the tracks around, sometimes it can’t.

So, if you’re reading this for hints on how to make the connections, use it as a guide to the type of thing you may need to do, but you may not necessarily be able to copy the steps precisely.

The other thing to note is that the connections on these PCB’s are usually very delicate, so you need to proceed carefully to avoid the narrow copper tracks coming away from the board.

As far as my gamepad was concerned, I used a Nyko Airflo, which was around £5 on eBay.

I removed the outside and an internal plastic piece which supported the two main PCBs and the fan which gives the Airflo its name.

Disassembled 2 IMG_1647

The idea was to reconnect the gamepad’s buttons to buttons on the FXBOX foot controller, so I detached the fan and looked for the button connections on the PCBs.

PCB 1 & 2 IMG_1650

Four of the 12 buttons were on their own mini-PCBs, connected by wires to the main board; the function of the wires was marked on the board, so I cut off the small PCBs and left the wires.

The various hatswitch connections and 6 of the remaining buttons were on the main board. These all had suitable spots in the copper tracks where it would be possible to solder wires.

The remaining two buttons were part of the joystick assembly on the second main board. It was easy to see the connections, and as the buttons were normally open (not connected), it would just be necessary to connect wires to the two sides of each one – or one side if the buttons all proved to have a common side, which is the usual practice.

I also needed to use the 4 potentiometers, two on each joystick, and wasn’t looking forward to de-soldering them, as I was anxious about damaging the tracks on the board. It doesn’t look too difficult on the videos, but I noticed on mine that there was small gap above the board where you could see the three legs of each potentiometer – the small ‘preset’ type – just enough room to insert a hacksaw blade and cut them off.   This is what I planned to do.

pots

First, as with the other devices in the Controller, I needed a much shorter USB out cable to connect to the hub, so I shortened the lead, but reconnected it before going any further, as this would be needed for testing.

The next step was to bring out the button connections to a ‘breakout’ board and find out exactly which ones I needed.

In most cases – perhaps all – I was sure that it wouldn’t be necessary to use 2 wires per button, as I had done with the Cybersynth; one side of the button connection would usually be Ground, and I hoped it would be possible to use one Ground connection for all of the 12 buttons.

This did prove to be the case, and I didn’t have the problem reported by some others of the unit not working at all without the joysticks connected.

I connected the 13 wires (one for each button + one for Ground) from the gamepad board to the breakout board, and a 13-way PCB header to give easy access to them.

The hatswitch connections looked as if they might be the same – except that there were 4 buttons, and I knew that 8 separate outputs are available from a hatswitch, meaning that 4 outputs were available from the 4 buttons individually and 4 outputs were available by connecting adjacent buttons simultaneously.

To make it easy to access these 8 outputs with 8 separate buttons, I connected diodes like this:

hatswitch-diodes-2

The connections at the top go to buttons in the Controller, and connections 1, 3, 5 and 7 at the bottom go to the 4 button positions on the circuit board; connections 2, 4, 6, 8 and 9 don’t need to be connected directly to the board.

This arrangement means that, for example, pressing Button 1 activates only Button 1, and pressing Button 3 activates only Button 3, but pressing Button 2 activates both Buttons 1 and 3 at the same time.

Only adjacent buttons are meant to be connected at the same time, which is why a hatswitch has 8 different outputs; but I discovered that connecting any two non-adjacent buttons on this particular board produced a ninth different output, recognised by PureData, which is why a ninth button is shown.

As a Ground connection was already available on the breakout board, I only needed 9 further connections for the 9 hatswitch buttons. This meant that 21 separate buttons would be available altogether.

*

The next task was to replace the two 2-axis joysticks with 4 potentiometers. Two of these would eventually be footpedals so that certain settings – volume and pan, for example – could be adjusted while playing.

I started by cutting through the legs of the existing potentiometers, as described above.  Once cut off, the potentiometers were easy to remove, exposing the three connections for each one.

Tracing the lines on the PCB, I could see that the ‘top’ and ‘bottom’ connections of each one were the same: only the middle pins had individual connections.

The bodies of the joysticks didn’t need to be removed from the board – and in fact were best left where they were, as some Ground connections from one part of the board to another appear to made through them.

I knew the potentiometers were likely to be more difficult to make use of than the buttons, but I was puzzled that I wasn’t able to get them working easily when I connected them to the board. For some reason they didn’t move smoothly from zero at one end to 255 the other as they were supposed to; on occasions they would return to zero and then refuse to move.

In the end, I read something that doesn’t seem to be mentioned much in articles on gamepad hacking, which seemed to be the root of the problem: joysticks are sprung to return to the centre of their travel, so a gamepad is expecting a midway reading on each one when it’s plugged in, and calibrates itself at that point to make sure the joysticks go back to the middle when let go. If potentiometers are used, and left at random values when the unit is plugged in, then the gamepad will get confused, try to calibrate itself wrong, and consequently fail to work properly – or at all.

The value of the joysticks in my gamepad was 100k, and they looked to be connected as voltage dividers, with the ‘top’ and ‘bottom’ tags all connected together, so, assuming these were +v and 0v (although it doesn’t really matter what they are) – I created a midpoint 50k from the top and 50k from the bottom (two 100k resistors in series = 50k). This would be connected to the centre tags of the potentiometer inputs to the board when the unit was turned on, the circuit would be calibrated, then the actual potentiometers could be connected and would correctly produce values from 0 – 255.

The writer of the article quoted above [http://kevinreems.com/WorkShop/Joysticks//] had a neat solution to this, using switched jack sockets, but I wasn’t able to use this method, as I wasn’t always going to be plugging into sockets. Instead, I connected the centre tags of the four potentiometer inputs to the centre tags on a 4 pole, two-way switch: this switch would be in the ‘off’ position when the unit was plugged in, which would connect the inputs to the ‘halfway’ voltage, enabling them to be calibrated, then when the unit was ready to be used the switch would be moved to the ‘on’ position, where the potentiometer inputs would be connected to actual potentiometers.

As a result, I ended up with a breakout board with 12 pins representing the 12 buttons numbered on the board, 9 pins representing the hatswitch buttons, 4 pins representing the 4 potentiometer outputs, and 3 pins representing +5v, 0v and +2.5v.

I also used 2 further pins for the game controller LED which lit up when the USB connection was made: I connected these to an LED on the outside of the case where I could see it and verify that the board was working.

That made 30 pins. Even when I calculated that I needed only 6 of the 9 hatswitch buttons, that still made 27 pins, plus 15 pins from the Apple keyboard PCB described earlier.

All the connections needed to be in place while the case was still open, so I needed to join all these pins on one side of the box where the circuit boards were to connectors on the other side of the box where the buttons were. To bridge this gap, I decided to use 40-pin ATA cables, normally found inside a desktop PC, which are inexpensive and compatible with the PCB connectors I was using.

ATA cables

These cables (as in the above picture) frequently have two separate connectors quite close together at one end. This made it easier to make connections not only from one side to the other, but also to special output sockets on the back of the case.  These could be used if alternatives were required to the buttons on the unit.

The 15-way socket on the back of the Controller has the same pin designations as my previous keyboard PCB-based project; the 25-way socket is a new arrangement, specific to the game controller:

Keybd & HID out DSCF0012

*

Finally, there was one downside with internal fixing of the Sonuus G2M ‘Guitar to MIDI’ unit – it runs off a PP3 battery: this would mean firstly that the ‘Battery low’ indicator couldn’t be seen from outside the case and secondly that the battery couldn’t be changed without taking the case apart. As this is held together with about 10 self-tapping screws, this would be too much trouble.

The main electrical supply was the the 5v adaptor that came with the USB hub, so I bought a small step-up voltage module for a couple of pounds to provide a 9v supply for the G2M.

voltage converter

I adjusted it to slightly over 9 volts, to make sure the G2M would be operated reliably and added a second power on/off switch for the 9v supply.

*

This is the almost finished base of the unit, showing the 7 elements.  All the connections are in place, except the power connector lead, which runs from connector 7 in the picture over to the power switches on the front of the unit:

Inside captioned IMG_1397

1: MIDI to USB

2: 7-port USB hub

3: Audio to USB

4: Apple keyboard PCB

5: Sonuus G2M, Audio to MIDI

6: Gamepad PCB

7: Power connector

This is the almost complete top section:

Top captioned IMG_1395

I gingerly put the two halves of the case together, and all the functions seemed to work, so I screwed it firmly together.

Now, with minimum use of the laptop keyboard, I was able to control the Looper with the buttons on the Top Panel:

Top Panel DSCF0009

and the FXBOX PureData program with the buttons on the Front Panel:

Front panel DSCF0010

I left space for additional button descriptions as the unit isn’t limited to controlling the Sooper Looper and FXBOX: in fact, it could be used to control any PureData patches which required [key] or [hid] inputs.

In addition to this, I had made provision on the front of the case for 4 footswitches which could duplicate the effect of any of the buttons on the panels:

Front DSCF0011

So far, I have just implemented two of the four possible: Footswitch 1 duplicates the ‘Overdub’ control in the Looper; Footswitch 4 duplicates the FXBOX ‘Freeze’ control.

I obtained some very nice momentary footswitches for only about £3 each from eBay.  They are apparently intended to operate tattoo machines, and have the advantage of coming with 1/4″ (6.35mm) standard mono jack sockets attached, perfect for this application.

tattoo switches

As for the footpedals, I haven’t implemented those yet.  When I do, I’ll describe this in a further post.

04
Nov
13

Fun with the Apple IR Remote, Part 3: Additions

In the previous post in this series, I dismantled and modified a white Apple infrared (IR) Remote control.

In this post I describe a foot controller which can be plugged into the DB9 socket on the modified remote, and then go on to consider what you can do if your Mac doesn’t have an IR receiver built in.

I had already constructed a very simple foot controller, which I had used with the Superstylonanophone.  The controller was  – well it was exactly what it looks like: a length of plastic guttering with a few push switches inserted into it, and a multi-way socket.

Footswitches1

There were just 4 buttons on the foot controller: two for bass drums and two for hi-hats.  These were connected very simply underneath: one side of each switch was a common connection, the other sides went to 4 appropriate pins on a 15-way D socket.

Footswitches2

It occurred to me that the same controller could also be used for the IR Remote, which also required a number of push switches with a common connection.  There would need to be more of them – at least 6 – and an alternative 9-way connector, but provided both connectors weren’t used at the same time, the controller could operate either device.

I had some spare buttons of the same type, so I added 3 extra ones in the spaces between the 4 originals (not in a very straight line between the 4 originals, it has to be said!), a new DB9 connector, and an LED which would come on when the foot controller was connected to the modified remote.

Outside DSCF0004

Only 6 of the buttons were required to duplicate the functioning of the Apple remote.  Using my IR Remote Tester in iRedLite, I verified that all the button presses – short, long and double – were being received and transmitted correctly from the six buttons I had wired up.  I connected the seventh so that the LED – which can be seen illuminated at the bottom of the picture – would go out if it was pressed, as a warning that it had no function.

Inside DSCF0003

I moved the bass drum triggers to the two leftmost buttons, and hi-hat triggers to the two rightmost.  At some point, when I revisit the Superstylonanophone, I can consider adding in further drums as there are now 3 spare buttons in the middle of the controller.

Connection DSCF0002

*

The foregoing is all very well if you have a MacBook, MacBook Pro or whatever, which has a built-in IR receiver – but what if your Mac doesn’t have this capability?

Fortunately, if this is your situation, all is not lost.  As I implied when discussing Joystick and Gamepad Tester, the Mac’s IR receiver is part of the USB system – this can be verified by checking the machine’s System Profiler:

system profiler ir receiver2

So, to add IR control, the ideal thing to get hold of would be an Apple IR receiver module which has a USB connection.

Luckily just such a device exists!

There may be a number of these, but the one I got was either Apple part number 922-7195 or 922-8355, not sure which: one is from a MacBook 15″, the other from a MacBook Pro; both have an IR receiver input and a USB output, so I daresay both would work equally well in this application.

IR Rec module IMG_0679L

I bought mine here: http://www.powerbookmedic.com/MacBook-Pro-Infrared-board-p-18041.html at a cost of less than £10, including postage from the U.S. – a bargain!  [Edit: and apparently still available 5 years later!  The part is still shown for sale on that website in October 2018.  The current MacBook/MacBook Pro no longer has this IR receiver in it].

I got the idea for this part of the IR project from this article: http://photos.pottebaum.com/2009/IR.  The aim was to install this module in a new case with a USB lead, thus enabling a Mac with no IR receiver to benefit from the remote, or to use  the remote at a distance or from an angle where a direct line of sight to the computer wasn’t available.

The new case I chose was this one:

IR REC front IMG_1567

It’s a Fisher Price ‘CD Player’.  It doesn’t, in fact, play CDs at all, but I picked it partly because of a definite stylistic connection with the modified Apple remote described above, partly because of its large front ‘window’ – which might allow for a certain degree of repositioning of the IR receiver inside – and partly because it was powered by three AA batteries, somewhat similar to the 5v provided by USB.

IR Rec back IMG_1568

I undid the 6 screws in the back (four of them are already out in the above picture, the two at the top remain), revealing the internal structure.

IR Rec inside IMG_1571

It was very well made, and very difficult to get apart as a matter of fact, as the two large white surfaces you can see were glued together.  It looked like blobs of a sticky adhesive which stretched when pulled, so I was able to prise the two halves apart slightly and cut the glue with a craft knife.

The speaker is visible in the top right-hand corner.  One of the three circuit boards in the unit can be seen at the bottom of the back section; the other two are underneath the two sides of the front section.

Circuit boards IMG_1569

The 8 press switches that can be seen on the tops of the circuit boards are operated by the 4 buttons on the front of the unit.  The switches are in pairs and the two switches in each pair are identical.

I tested each switch in turn and noted their outputs.  They worked by cycling through a number of samples: a short bell-like tune, some spoken phrases (‘Sing with me!’, ‘Oh, yeah!’ and ‘Let’s Boogie!’) and some longer songs with voices and instruments (‘One, two, buckle my shoe’, ‘Itsy-bitsy spider’, ‘Row, row, row the boat’, and some songs that sounded as if they may have been specially written for the unit).  Three of the pairs had a 9-step sequence, one of them a 6-step.

I wasn’t, in this instance, interested in the songs, as I wasn’t intending to circuit bend the device, but I wanted the LEDs to come on when IR input was received.  The best LED display was seen while a song was playing; during the bell tune and the spoken phrases the lights came on only for a short time.  The sequences weren’t the same for each button, and I decided that button three (bottom left)  was the best one to concentrate on, as there was a higher proportion of songs in the sequence compared to short phrases.

Steps in the sequence were initiated simply by a short +V pulse to an appropriate point on the PCB, which should be easy to generate.

*

First of all, however, I needed to connect up the IR receiver module.

Being color-blind, I’m always nervous about connecting up colour-coded wires – especially to a USB plug which would be going into my laptop.  However, the module seemed – to my eyes at least! – to follow the conventional red-white-green-black USB wiring scheme (+5v, Data +, Data -, Ground, in that order), so I snipped off the small 4-way connector it came with and connected the four wires to a short length of multi-core cable.  The other end of the multi-core cable was connected to a USB plug, via a small PCB connector.  There was no PCB: this was just a convenient way of joining together various wires – the four USB wires, power leads from the batteries and some others I’ll explain shortly.

So, the Apple IR receiver module was connected to a USB plug.  I didn’t want the unit to have a long lead trailing out from it, so the lead to the plug was kept very short, and plugged into a small USB hub which I fixed to the battery compartment lid on the back of the unit:

hub IMG_1585

hub 3 IMG_1587

It was an excellent little hub – only £2 or £3 on eBay, and capable of being powered, if required.
Now ready for testing, the unit looked like this:
Back&Front_IMG_1603

The new receiver module can be seen lying in the middle of the front of the unit.  The short USB lead and plug can be seen emerging from the back, and at the bottom of the picture the mini-USB lead goes from the hub to the laptop.  The purpose of the three unused wires in the multi-core cable is explained later on, and is not to do with the Apple receiver.

Checking in the System Profiler, I now saw two IR Receivers instead of one:

System profiler 2510

I experimented simply by covering up one or other of the receivers and making sure, using iRed Lite, that my remotes – especially the new modified one – were able to control various functions in Safari and would print the correct numbers in Text Edit.  The two receivers seemed to work in tandem on the MacBook – it didn’t matter which of the two I covered up, the other would immediately register the button presses and carry out the required function.

*

The vital question was: what would happen if I connected the unit up to a computer that didn’t have a built-in IR capability?

I started with my eMac, which runs the same OS as the MacBook, 10.5.8.  I checked the System Profiler – no mention of an IR receiver; then I plugged the unit in and was gratified to see the IR receiver shown (I needed to close the System Profiler and reopen it to make the new device show up):

eMac before&after IMG_1605

I didn’t have Joystick and Gamepad Tester or iRed Lite installed on the eMac, so I had to content myself with testing the functions the remote normally performs on a Mac – opening and closing Front Row and turning the volume up and down.  Using the new modified remote, I confirmed that it would do this.

I then tried the same procedure on an old G5.  I can’t remember what OS it uses, but I think it’s either 10.5 or 10.6.  Once again, using the System Profiler, I verified that no internal IR receiver showed up at first, but when plugged in the new device was registered:

G5 before and after IMG_1608

The one thing that did appear first of all in the USB section was my iPazzPort.  I’ve described in a past post what this is – a very handy little device, no more than 4 or 5 inches tall, which duplicates the function of the keyboard and trackpad:

iPazzPort_IMG_1607

As can be seen, it connects via USB – not a problem, even on the G5, which only has one USB socket on the front, as I was able to plug it into the hub on the back of the new receiver and use the two devices together.

Once again, the remote worked exactly as intended, proving that IR functionality could be added to a Mac which originally had none.

*

I didn’t immediately reassemble the unit, as there were a couple more things I wanted to do with it.  First of all, as mentioned earlier, I wanted to include a method of making the lights flash when an infrared signal was received from the remote.  As described, this needed something to give a +V pulse when the signal came in.

I didn’t want to interfere with the Apple receiver module, so added a second IR receiver like this:

AX1838

This device, an AX1838, has three leads: two for the power supply, with the third giving an output when it detects an IR input.  It wouldn’t be necessary to interpret the input – which is what the Apple module does – just give an output pulse on receipt of a signal.  Unfortunately, according to the data sheet, the output of the device goes low when IR input is detected, not high, which is what the ‘CD Player’ circuit requires.

I was under the impression that the low level output from the device would be sufficient, when inverted, to operate the switch in the CD Player, but this wasn’t the case.  In the end I looked around at circuits for simple infrared-operated switches, and used an adapted version of this one, using just three components, a BC588 transistor, a 22μF capacitor and a 100k resistor.

Apart from the existing electronics concerned with playing the samples and sequencing the lights, the electronics I added to the device looked like this:

IR Receiver Electrics Revised2

In fact, this is what I intended, but as I didn’t have a 100Ω resistor, I added a 470Ω instead.  I don’t know if this was too large a value, but I’ll find out when I come to use the wii later.

I didn’t bother with a piece of stripboard, I just wired everything up to the three legs of the transistor.  This addition to the circuit seemed to have the desired effect: the output of the transistor is normally kept low; an incoming IR signal is detected by the AX1838 and as the capacitor charges up the multiple signals are smoothed out into one.  The output of the transistor goes high and is boosted to a level sufficient to operate the CD Player switch and turn on the lights, giving a visual indication that an instruction has been received by the Apple IR receiver.

Stiff wires were attached to the two IR detectors, anchored inside the unit, so the detectors could be repositioned within the CD Player front window.

*

Finally, while on the infrared theme, I just had two more things to do  before reassembling the finished unit.

Firstly, I added two infrared LEDs to the front of the unit.  These had nothing to do with the receiver or the flashing lights: they’re a little closer together than the original, but they’re designed to duplicate the function of the wii ‘sensor bar’.

IR LEDs IMG_1609

I’ll be blogging about the wii system later, but the ‘sensor’ bar’ is a most inaptly named device, since it doesn’t ‘sense’ anything at all, but instead provides two points of infrared light which the wii remote controller – or ‘wiimote’ – uses to fix its position.  Being a little closer together than the Nintendo original isn’t a problem – the wiimote might just think it was further away from the sensor bar than it really was.  As I’m not proposing to use my wii controller for playing sports, I don’t anticipate a problem with this.  Further information will appear in my wii posts.

The new infrared device had one more secret, hidden in the carrying handle:

Candles 1 IMG_1612

There are many reports on the internet of wii users who have substituted candles for infrared LEDs when using their wiimote, so I thought I’d guard against battery failure in the unit by adding candle holders – the kind you buy for birthday cakes.  Believe it or not, this does work!

*

Front & Back

After reassembling the unit, and thinking again about the wii remote, I added an extra external item to the USB hub: a tiny Bluetooth dongle.  I found this in Poundland, for £1 (obviously!) and thought for that price it would be worth experimenting with.

22
Oct
13

Fun with the Apple IR Remote, Part 2: Modifications

In the first part of this series of posts, I described the Apple infrared (IR) Remote system and some software which allows you to use the IR signals for controlling apps on the Mac.

In this post I take a closer look at the Remote controller itself, and describe the way I modified mine.

I must say that I’m not familiar with the silver aluminium remote, although I have no reason to believe it’s substantially different on the inside from the original white remote.  This is the one I have experience of.

What’s good about the white remote is also what’s bad about it – it’s very tiny.  This is great if you just want to tuck it away somewhere and not have a bulky TV/DVD player-type remote to lug about, but not so good from the point of view of it easily being overlooked or mislaid.

So, one reason you might want to modify the remote is to make it larger and more suitable for the human hand.

Frankly, the most cunning solution to his problem is the one described here by Brad Moon.  I hope he won’t mind me using his picture:

Remote wood block

Yes, what Brad has done is simply to glue his Apple remote to a hand-sized piece of wood.  Job done!  As he says in his blog post: ‘Too big to lose, too big to slip behind a cushion or slip into a pocket . . . The Apple TV remote hack has been in place for roughly a month.  In that time, the remote has been lost exactly zero times.’

This certainly takes care of the problem of the unit itself being rather small, but to address the problem of the size of the buttons themselves and their awkward layout, the unit has to be taken apart.  At the time of writing, you can still get hold of these white remotes on eBay for about £3, so if you want to try this, there’s no need to sacrifice the one that came with your Mac.

This is how it’s done:

1_IMG_1533

The picture above shows the unit and the tool (or maybe one of the two tools) you need to open the remote unit.  This is a small Philips or crosshead screwdriver.

As well as being used in a moment for taking out screws, the first thing you can do with it is poke the small depression on the right-hand side of the base of the remote unit.  This releases the battery tray, which pops out on a spring:

2_IMG_1534

Next, you have to undo a screw which is right down inside, next to the release button:

3_IMG_1536

Undo the screw and take it out:

4_IMG_1535

The next bit is the most difficult.  On the opposite side – the lower side in these pictures – is the spring which pushes the battery compartment out.  The spring is firmly attached to the bottom of a small piece of plastic, and you have somehow to grab this piece of plastic and pull it out, with the spring on the bottom of it.

The next picture shows what the spring and the plastic piece look like.  You might reach in and grab it with tweezers or narrow long-nosed pliers, but it’s right up against the edge of the case, and hard to get hold of:

6_IMG_1538

If you look at the full-size version of the picture, you can see that the piece of plastic has tags on it, so I was able to poke the screwdriver under a tag and drag the plastic and spring out.

Underneath where the spring was is another small screw.  Unscrew this and take it out:

7_IMG_1539

You can then pull the battery compartment out.  I did this with a pair of narrow pliers, gripping the white release button, which you can see in this photograph.

8_IMG_1540

Then you can push out the remaining parts left inside the case.  I did that by inserting the screwdriver here:

9_IMG_1541

The circuit board, with the springy battery connectors behind, slid out very easily:

10_IMG_1542

You can carefully detach the end  piece from the circuit board, clicking it off the tabs which hold it in place over the end of the board and the IR LED:

11_IMG_1543

This an exploded view of the remote, with all the parts visible:

11B_IMG_1547

Putting it back together, of course, is the reverse of this procedure.  The trickiest part is undoubtedly getting the spring and its plastic top back in.  This video by Andrew Williams, to which I’m greatly indebted: http://www.youtube.com/watch?v=vuP6CH770NM shows a remote being put back together, and explains the direction in which the tabs must face – front and back – for the plastic piece to go back in the correct position.

*

I wasn’t interested in putting it back together again, so I looked more closely at the circuit board:

12&13_IMG_1545&6

You can see in the top part of the picture the infra-red LED and the 6 buttons.  You can also see 4 screws which attach the circuit board the the plastic fitting.

The first thing to do was take off the six silver ‘domes’ which make the contacts when the buttons are pressed, and see what connections they made.  These are often, in my experience, attached together to a transparent sticky sheet which peels off, and so it was in this case.

Remote PCB IMG_1554

As you can see from this photograph – taken after I’d removed the four small screws holding the PCB to the plastic fitting – each button makes a contact between an outer ring and a centre spot.  All the outer rings were connected together, to what looked like +V, while the six centre spots were separate.  What I wanted to do was transplant the board into a larger unit, so I needed to solder seven wires to the board, and connect them to buttons in the new unit.

The larger unit I’d chosen was this one:

vtech_tinytouch_phone

This is a vtech Tiny Touch Phone: it’s powered by two AA batteries – 3v, same as the Apple Remote; has 12 buttons – exactly twice as many as the Remote, which could be handy for dissociating short, long or double presses; and has flashing lights – which is always good.  It also makes sounds, and under normal circumstances I would be looking to ‘bend’ these, but in this instance making noises wasn’t what the project was all about, so I decided I’d remove the sounds completely by taking out the speaker.

The Phone also has a hollow plastic ‘antenna’, which was perfectly placed for installing the IR LED.

aerial

This is what it looked like inside.  In  this picture the large mechanical unit, which looks like the film sprockets in an old 35mm film camera is obscuring the speaker housing.  With the speaker removed there looked as though there’d be plenty of room for the small Apple Remote PCB there.  The wires for the LED could easily pass from there up into the antenna.

Phone inside IMG_1552

The general idea would be to rewire the button connections on the Apple Remote PCB to the Tiny Touch Phone buttons.  The Phone buttons (visible in the first picture above) are, however, hollow, and make connections with a membrane, rather like  QWERTY keyboard, via their edges .

I wanted to leave the membrane intact, to operate the flashing lights, so I decided to add small tactile switches with longish 3.5mm actuators which would be glued in the hollows with the actuators sticking out through a hole in the top of the Tiny Touch buttons.  It was these switches which would actually operate the IR remote.

Gluing these in without gluing them together so they wouldn’t function proved difficult.  Letting superglue anywhere near them – even the gel type which I usually use – could prove fatal, as it has a habit of running everywhere.  In the end I used epoxy, which is stickier and less runny, and tiny pieces of tissue paper soaked in epoxy to keep the switches in place.  The moon and star buttons aren’t hollow, so I stuck tactile switches with short 1mm actuators to the top of them, on the outside, with wires running in through a small hole.

In the end I only connected up the star: it would have been difficult to make the hole in exactly the right place in the moon and route the wires inside without disturbing the membrane too much.  The star operates the ‘Menu’ button, which is less important than the others and doesn’t require more buttons to distinguish types of presses.

Buttons IMG_1550

In the event, all but one of the tactile switches worked after this treatment, which was OK, as there were two new buttons for each button on the original remote, so all functions would still be available.

To modify the new unit, I first removed the speaker and replaced it with a resistor (two 22Ω resistors in parallel, actually, as I had these lying about.  I didn’t have any 8Ω resistors to match the speaker, but 11Ω, I reasoned, was close enough).

This created enough space in the top of the unit for the small Apple remote PCB.

I reinstalled the buttons in their places and connected the tactile switches together.  One side of each switch was connected to +3v, the other sides of the switches were connected together in pairs (except the moon, as explained above).  This made 7 extra wires running down to the bottom of the unit.  The presence of the wires might have an effect on the operation of the TouchPhone’s original buttons, but this wasn’t important as their only function now was to light up LEDs when the remote was operated, a feature which Apple neglected to provide in the original.

Buttons_connector_IMG_1574

As can be  seen in the above picture, there was just about enough room for a 9-way D socket in the base of the unit.  I put this in partly because it would allow for external operation of the 6 remote buttons – perhaps by means of a footswitch – and partly because it provided a handy link point between the tactile switches and the Apple remote PCB.

To attach the remote PCB, wires were connected to the centres of the 6 switch points, and one of the outer rings, which were all connected together on the board.  3v and 0v power cables were connected to the springy metal pieces which formerly connected to the coin-battery in the original remote housing.  These connectors were shortened in order to fit the PCB neatly in the space where the speaker had been.

PCB_LED_IMG_1577

At the same time I detached the infrared LED and put it on the end of a longer lead, so it would reach to the front of the unit when in operation.

At this point everything was connected up, although not back in place, so I made a quick check, using iChat and the laptop camera in the way described before.  I pressed all the buttons in turn, pointed the unit at the camera, and watched for the infrared LED to come on.

When I was satisfied that it did so, I replaced the membrane and the TouchPhone PCB, as this would make pressing and testing the buttons a great deal easier.

*

For the next step I needed a way of thoroughly testing if the remote worked as intended.  I did this by creating a Tester program, using iRedLite.

It takes quite a few steps to create a ‘Layer’ – a set of instructions for each remote button – in iRedLite, but this is how I created a ‘Remote Tester’.

The ‘Menu’ button has special functions in iRedLite, but the other 5 buttons respond to short presses, long presses and double presses, so 15 separate instructions would be required.  What I decided to do was use Text Edit, and simply have it print the numbers 1 – 15, according to which remote button was activated.

Step 1 was to open iRedLite.  You can set it up in various ways in the preferences, but I have it set so it just opens an icon in the menu bar:

1 iredlite menu bar

The first step is to select the Editor from the drop-down menu:

2 Show editor

This brings up the Editor screen.  The top half of the window is a copy of what iRedLite calls the OnScreen Display (OSD).  The bottom half allows you to edit Layers and Buttons, and select the actions the buttons perform.  I began by creating a new Layer for my Text Edit actions:

3 New Layer

Then I entered the details of this Layer:

4 Name new layer

I typed a name for my Layer into the ‘Title’ box, and then made choices about what would happen when the Layer was selected.  I chose not to have the Layer activated when I switched to Text Edit, in case I wanted to type some text while using iRedLite with another application; but I did choose to have Text Edit activated when I switched to this Layer, because the actions all required text to be typed in it.  I have several remotes, so to be certain which remote was being tested, I set it to respond only to a particular one: in this case, the one with the ID No. 214.

Having finished creating the Layer, I clicked on the small arrow in the bottom right-hand corner of the Editor window.  I believe they call this the ‘Expert’ button, but it’s simply for accessing the section where actions are created and organised.

5 Editor window

Clicking this button opens the right-hand side of the Editor.  In here, if you look in the ‘Application’ column and can’t find the application you intend to use the remote with, click the ‘+’ button at the bottom of the column to add it to the list:

6 New Application

Type the application name in the box which appears.  The program will be recognised if its name is written the same as it would appear if you moved your mouse over it in the Dock.  Text Edit is actually written ‘TextEdit’, so that’s what I typed in the box:

7 Type New Application

Next you have to create a ‘Group’ – not for any special reason, I don’t think: it just works that way.  If you create a lot of actions for one particular application, this allows you to put different types of actions together, i.e. Keystrokes in one Group, AppleScripts in another, and so on.

I just wanted keystrokes, so I created a group called ‘Keys’.  Group names are your personal choice.  Once again, I clicked the ‘+’ sign under the ‘Groups’ column, and typed ‘Keys’ in the box which appeared.

8 New Group

Then it was time to create some actions.  Each action is entered individually, so I had to click on the ‘+’ sign at the bottom of the ‘Actions’ column 15 times, name the actions in the boxes which appeared, and specify what was to be done.

They were all more or less the same, and this is an example:

9 Create actions

Click the ‘+’ sign; name the action – again, this is entirely your choice: I just called them ‘1’ to ’15’; type the name of the application, or choose it if it appears in the drop-down list; check the box if you need the application to come to the front – which I did, because I wanted to read what it had printed; and type in what keystroke or keystrokes should be made.

Allocating the actions to the buttons is just a matter of dragging and dropping the action onto the appropriate button, and clicking ‘Assign Action’:

10 Drag and drop

The button will be given the name of the action – in this case ‘1’, which is the name I had given to the first action, which was to print the number 1.

11 Button number 1

You can rename the button, and I did, calling it ‘1/2’.  This is the reason why:

iRedLite shows the pattern of buttons in the way that it does to indicate that the button nearest the centre performs the short press action (which they call ‘Action on click’), while the button on the outside performs the double press action.  In reality, of course, these actions are performed by pressing exactly the same button on the remote, but it makes it clearer to see which number of presses produces which action.

So the ‘short press’ and the ‘double press’ are specified, but the ‘long press’ action (which they call ‘Action when holding’) remains to be allocated.

I decided to add the long press action to the instructions for the inner buttons, so in the example below I selected the appropriate inner button (Action 4, the ‘+’ button on the remote) and the ‘Advanced’ tab.  This allowed me to drag and drop the action I wanted to be performed as the long press action, printing the number ‘5’.

12 Button 4_5

I added a long press action to buttons 1 (the ‘Left’ button on the remote), 4 (the ‘+’ button), 7 (‘Right’), 10 (‘-‘) and 13 (the centre button) and renamed the buttons in iRedLite accordingly (‘1/2’, with ‘3’ being the double press action for that button on the remote; ‘4/5’, with ‘6’ as the double press, and so on).

When I’d finished, the set-up looked like this:

13 Finished

Note the button in the top right-hand corner,  marked ’15’.  There are 12 more places in the grey area of the button window where you can drag and drop actions, 6 on the left and 6 on the right.  If you drag and drop an action somewhere in the grey space, a new button will be created there.  This might come in handy if you had a modified control with differently positioned buttons.  In this case, I used one of the spare places for the double press action associated with the centre button.

Removing buttons, should this be necessary, is one of the functions on the drop-down menu where I chose ‘New Layer’ at the beginning.

I opened Text Edit and pressed all the buttons in order, single press first, then long press, then double press, hoping to see the numbers 1 to 15 displayed.  This what I saw:

14 Text Edit Numbers

The numbers were all printed out in order, so the combinations of short press, long press and double press all worked as predicted – but the long presses produced a continuous stream of outputs, even though I tried to take my finger off the button as quickly as possible.  The exception was the Centre button, which produced a single output of the number ’14’, no matter how long I held the button down.

This behaviour might not be what you require if, instead of printing numbers, you want a single specific action to be performed.  You might find the action repeated many times unless you’re able to take other steps to avoid this.

However, for testing purposes, this was fine, and I had established that the remote should, with iRedLite, be able to distinguish between 15 separate actions, despite only having 6 buttons.

*

The final stage of the project was to try out the new Tiny Touch Apple IR Remote to see if it would function correctly, using the iRedLite TextEdit Tester.

I quickly opened Joystick and Gamepad Tester to check the ID number of the new remote, which was 211.  I then opened iRedLite, went to the correct Layer for my Tester, and changed the remote number to which it would respond from 214 – the remote I had originally use to create the Layer – to 211.

The TouchPhone has a Power switch, but in fact the IR Remote worked even when it was in the ‘off’ position; in the ‘on’ position it worked with added lights.  As before, I pressed each button in turn with a short press, a long press and a double press, checking to see that the correct numbers were printed in Text Edit.

They were, so now it was safe to put the unit back together.  I glued the IR LED into the ‘antenna’:

top IMG_1580

fixed the 9-way socket in place:

bottom IMG_1584

and  wrote the ID number on the back.  Now I had the world’s most colourful Apple IR remote!  It could have been the world’s noisiest, had I not removed the speaker, but I felt this would be gilding the lily – and would probably have been a distraction, given that I had conceived of the remote as being part of a sound-modifying system, not a sound-producing system.

Alternative Remote

I was a little upset as, just as I was putting it back together, I broke the plastic link behind the ‘telephone’ button that mechanically ‘winds the film’ and changes the picture on the screen.  However, this only deprived me of more ways of turning LEDs on, and didn’t in any way affect the IR  controls, so ultimately I was satisfied with my achievement.  I didn’t want to spend more time on it at this stage as I wanted to move onto the next part of the IR project.

For this, see Part 3: Additions.

 

[Edit: I’ve since managed to get hold of another Tiny Touch Phone and replace the broken film winder, although I haven’t yet had time to change the tactile switch that got glued together].

15
Sep
13

The StyloSound

front_IMG_1497

The idea for the StyloSound came to me when, at about the same time, I acquired two small sound effect devices.  One was a ‘Sound Machine’, a small hand-held unit with 16 push-buttons, the other was a Sound effect kit with PCB, also with 16 different sounds.  I thought it would be a good idea to combine the two things into one unit and use the Stylophone stylus to trigger the sounds; plus I was also working on devices to interact with the ‘Bigfoot’ trigger/sequencer, so I decided to add the capability for the sounds to be triggered by the Bigfoot’s 4-bit binary output.

*

There are several varieties of Sound Machine.  The one I got was the silver ‘SciFi’ version.  This has a number of interesting ‘spacey’ effects, some of which I recognised from Star Wars, Close Encounters and others; some I didn’t.

sound-machine-sci-fi-box2

These Sound Machines aren’t all exactly the same inside, apparently (this site gives a very good first-hand account of looking inside them: http://www.magicmess.co.uk/cb/sm.php)*, but I guess the sounds are all initiated the same way – a +V pulse into the appropriate input of the dedicated chip which stores the samples.

*[Edit: unfortunately, this site is no longer up; I saved some of it, which had this information in it: http-www-magicmess-co-ukcbsm-php.pdf].

Having opened the Sound Machine and taken the PCB out, it was easy to attach a wire to each of the 16 inputs.  These wires went to the middle 16 notes on a Stylophone keyboard, salvaged from a broken instrument – via 16 SPDT switches, as I wanted to be able to choose either the sound from the Sound Machine or the sound from the Sound effect kit individually in each of the 16 positions.  This picture shows how the switches were arranged on the front of the StyloSound:

StyloSound outside in prep IMG_1469

The Stylophone stylus was connected to +V, and the output from the Sound Machine PCB went to the Stylophone speaker, which was much better than the small speaker in the original.

The Sound Machine is powered by three small 1.5v button cells, so it was no problem to use the Stylophone’s own battery compartment, which takes three AA batteries.  With all the switches to the left, the Sound Machine PCB was selected, and it was possible to play all 16 sounds from the Stylophone keyboard.  It was clearer from this than using the original buttons that each sound has to play right through before a new one can be selected.

The next obvious step was to interfere with the playback speed of the sample.  This version of the Sound Machine has only four visible components, two resistors and two capacitors – all tiny SMD (surface-mount) type – with the main chip embedded in its plastic blob.  Using the wetted finger method, I found the resistor responsible for playback speed, which is marked ‘R2’.  I removed it and replaced it with a potentiometer, which slowed down and speeded up the playback.

In this photograph you can see the points at which wires are soldered to the Sound Machine PCB.  In the magnified area you can just about make out the resistor on the left marked ‘R1’, the removed resistor, ‘R2’ (detached but still lying beside the place it was removed from), the wires going to the potentiometer and the two SMD capacitors behind the wires:

SMachine PCB IMG_1473

Unusually in my experience, the chip reacted badly to both too low a resistance and too high, and a 1M potentiometer, my usual first choice, was too big for it, causing it to crash.  In the end, I settled on a 470K potentiometer with 100k trimmers either side.  When the trimmers had been adjusted, this seemed to keep the resistance within acceptable levels.

(Later, I read the website referenced above, and the writer had a different solution to this problem, but I didn’t have time to check it out).

*

The above is all you would need to do to bend a Sound Machine, but the next thing in my case was to unpack the Sound Effect kit, which contained the following components:

Kit unpacked IMG_1471

The two logic chips are a 4066 (quad analog SPST switch), and 4011, (quad 2-input NAND gate); the sound effect chip was on a separate board, inserted, strangely, at right angles to the main board in the slot on the right.  The 4 SPDT switches enable the sound to be selected manually – the input is 4 bit binary – as an alternative to the 4 inputs on the left-hand side of the board.  Output is  through what looked like a small piezo element (the round black component in the bottom left of the picture).

The small board which the sound effect chip itself sits on is one of a range in the 9561 series.  This one has the prefix ‘LX’, but there are others, such  as ‘CK’, ‘CL’, ‘CW’, ‘KD” and others: all have the same general purpose, finding use in alarms, doorbells, and simple toys, making noises such as police sirens, machine guns and so on.  Simple circuits such as this one can be found on the internet utilising very few external components to produce the required sound (generally only one or two in each application):

LX9561

In fact, the kit I bought in an eBay auction only cost about the same as the module itself, and took full advantage of the range of sounds available by using the two switching terminals (F1 and F2) and a more complex array of resistors in place of the single 200k resistor shown in the circuit above.  The full list of sounds available is as follows:

0000: Machine gun voice
0001: Fire truck voice
0010: Ambulance voice
0011: The police car voice
0100: Crickets sound
0101: Alarm
0110: Electronic signal sound
0111: Koh
1000: Insect song
1001: Whistle
1010: Telegraph sound
1011: Bird song
1100: ChongJi gunfire
1101: Car sirens
1110: Bass instruments sound
1111: Racing sound

Some of these interpretations are rather fanciful, but that was no problem as I was more interested in making noise than repeating recognisable sounds.

This chart – for a similar chip in the series – gives some idea of the variations in binary inputs, combinations of selection inputs and resistances that produce different sounds.  If you read Chinese, which I don’t, it probably tells you in the right-hand column what sounds these combinations make.

KD9561 selection chart2

The PCB was robustly constructed and I put it together omitting the four slide switches, as I intended to control it externally, and didn’t attach the piezo sounder, which wasn’t going to be used.

Several of the resistors, when tested, had an effect on the pitch and speed of the sounds – the main job of the 4066 and 4011 is to select different combinations of resistors to affect the sound produced, much as indicated in the chart above – so I picked the likeliest one and replaced it with a 1M potentiometer.  This seemed to do the trick – perhaps taking things slightly too far in the upper direction, so I added a preset in series to keep it from going to its maximum – although it had happily done this without any danger of crashing the chip.

I only had a log potentiometer available, and in the end this was quite fortunate.  I found that connecting it the opposite way round from what would be expected – i.e. turning it clockwise decreased the pitch and speed, rather than increasing it – exploited the logarithmic scale well, making a much slower and smoother transition through the higher pitches and speeds.  I could have bought an ‘anti-log’ pot, but additional time and expense didn’t seem worth it.

This was a timely reminder that a useful part of experimentation would be to compare lin and log pots in particular situations, and reversing the log ones to see what difference this produced. (Reversing the linear ones would, of course, do no good, as they progress evenly through the scale from top to bottom, whichever way round they are).

This part of the circuit (the kit PCB) now looked like this:

Sound Effect Kit circuit 3

The original circuit diagram was provided by the supplier, Chip_Partner_Store, a Chinese company with an eBay shop at http://stores.ebay.com/Chip-Partner-Store.  Places like this – and there are many of them on eBay – are great for browsing through: you can find great deals on bulk buys of common components, as well as somewhat more unusual ones at very reasonable prices, and odd chips and modules like this one, which could always come in handy.

I’ve indicated in the diagram where I added the 1M potentiometer and preset, plus four LEDs, connected, via 470Ω resistors, to the A B C D inputs, the other ends connected to ground.  These were not there for any reason, particularly, except as an indicator of the code being received – and on the principle established with Bigfoot that flashing lights are always good.  I was sceptical as to whether the circuit supplying the four inputs would be able to power these as well as operate the Sound effect module correctly, but it all seemed OK.

The greyed-out section at the output wasn’t used in the final circuit.

Actually, this unit begins sounding repeatedly as soon as power is connected to it, since the default input 0 0 0 0 has an associated output – ‘Machine gun voice’ – and I couldn’t find a way of stopping it, so I also added a power on/off switch to this board, which isn’t shown, in case this feature became annoying.

*

SInce the circuit has four binary inputs, and I wanted to control the unit with the Bigfoot, which has a 4-bit binary output, it would seem logical to connect the Bigfoot output directly to the A B C D inputs.

Unfortunately, this wouldn’t allow the Sound effect module to be operated by the Stylophone keyboard, or the Bigfoot to control the Sound Machine, so additional circuitry was needed to convert the binary input into 16 individual outputs, and then convert that back into binary . . .

. . . Fortunately, the first of those would be a duplicate of part of the Bigfoot circuitry, which I was familiar with, using a 4067 chip.  This part of the circuit looked like this:

StyloSound - 4050_4067_3

The input from the 5-pin DIN socket goes first to a 4050 hex buffer.  Four of the six buffers are used.  The reason for doing this is to exploit an unusual and very useful feature which the 4050 shares with its more common sibling, the 4049.

Both perform a similar function, but the 4049 inverts the input (high level voltage in = low level voltage out, low level voltage in = high level voltage out), and the 4050 doesn’t.

What both of them are able to do is accept an input voltage level higher than the supply voltage, a vital consideration here as the output from Bigfoot is at 9v, whereas the circuitry of the StyloSound is at only 4.5v.  The 4050 is able to acccept the 9v input from Bigfoot and safely reduce it to 4.5v for the other circuits.  9v isn’t a problem for CMOS chips, but the Sound Machine and the Sound effects module are both rated at 4.5 – maybe 5 or 6 maximum – volts.

The four outputs of the 4050 go into the A B C D inputs of the 4067.  Each of the 16 outputs of the 4067 goes to the pole of one of the SPDT switches described earlier.  According to the binary coding on the inputs, one of the 16 outputs of the 4067 is connected to +V, and this signal is sent in the direction either of the Sound Machine when the switch is to the left, or the Sound effect module when it’s to the right.

*

The Sound Machine has 16 separate inputs, so no further circuitry was required: each switch was connected to one of the 16 places on the Sound Machine PCB where there used to be buttons.

For this signal to operate the Sound effect module, however, it needed to be changed back into binary.

Fortunately, this change is not difficult to implement, using a pair of 4532 chips and a 4071.  The 4532 is essentially the opposite of the 4067: it takes individual inputs and converts them to binary.  Each one has only 8 individual inputs and outputs in 3-bit binary, but the datasheet showed this 16-input, 4-bit binary output circuit, which is the one I used:

16 input encoder w pin Nos

The 16 inputs marked ‘From Stylophone Keyboard’ were all connected to ground with 100k resistors so that each one would be at 0v if not receiving a +V signal from the keyboard or the 4067.  The outputs of the 4071 were connected to the Sound effects module where marked A B C D in the earlier diagram.

Here’s how the physical connections are made, and what the chips look like on the board:

StyloSound 4532_4071_3

inside_IMG_1472_2

I’m not entirely sure that the correct order of those 16 inputs is as implied in the datasheet circuit.  Since I had LEDs on the inputs of the Sound effects module – i.e. effectively at the outputs of the 4071, I was able to check the sequence, and I found myself swapping some of them around.  If you’re using this method of converting single outputs to binary, it would be advisable to check this as you go along.  In my case, the wiring to and from the SPST switches was such a bird’s nest, that it became too difficult to work this out.  If it becomes clearer when I use this system in future projects, I’ll make sure to record the correct sequence.

However, when tested with ‘Bigfoot’, the module was triggered accurately, and the LEDs on the input lit up with the correct numbers when the notes were tested with the stylus and keyboard.

*

So now I had two separate sound effect circuits which differed in several ways: the Sound Machine uses samples, which are played back in their entirety, and are particularly effective when slowed down; the Sound effects module produces electronic sounds from oscillators, which can be cut off and replaced at any time by another sound, and lend themselves to being sped up.

Both sections had separate pitch/speed controls; both could be controlled automatically by Bigfoot, or manually via the Stylophone keyboard.

*

I could have stopped there, but I had another idea which I thought could be included.  I believe this is known in the trade as ‘feature creep’ – just adding that one extra implementation, which then turns into two, then three . . . and eventually makes a simple circuit over-complicated.

But I had  just acquired a number of unwanted ‘Voice Recorder’ key rings – 100, in fact! – at a few pence each.  At this price, they weren’t guaranteed to work, but when I tested some, quite a few seemed OK, and they were powered by 3 little coin cells – i.e. 4.5v, the same as the rest of the circuits in the StyloSound, so I thought I could employ a couple of them here.

Here’s what they look like:

outside_inside

There’s a very small microphone, a Record/Play switch, a button to operate whichever of the two functions it’s switched to, and an LED to indicate that it’s recording, as opposed to playing back.  I thought it would be good to be able to record a small (up to 8.2 seconds, it said) burst of sound while the samples or effects were being manipulated, then be able to play it back precisely the same again, a primitive – but undeniably inexpensive – repeat/looping device.

So I added a couple of these, connected to the outputs of the Sound Machine and the Sound effect module.  Small tactile switches glued to the front of the instrument replaced the ‘Record/Play’ switch and button, and I also moved the small LED’s to the front panel as well.

*

Only one thing remained, as far as the circuit was concerned, which was the output stage.  This turned out to be . . . strange.

First of all, I needed to mix together the four outputs: the Sound Machine, the Sound Effects module and the two recording devices, as well as send the Sound Machine and Sound Effects module outputs to the inputs of the recorders.  I planned to do this  with a passive mixer – i.e. just join the outputs together with resistors.

The Sound Machine worked perfectly with the internal speaker, but the Sound Effects module would only work with the other speaker terminal connected to +V rather than 0v: otherwise, it was extremely quiet.  I got round this by taking the output directly from the output of the LX9561 board, as indicated in the circuit diagram above, and bypassing the output transistor.

The outputs of the recorders were much too quiet, too, and the only way I could make them loud enough was to give them a path to +V by means of a very low value resistor (22Ω).  The sound quality of these didn’t quite match that of the Sound Machine and Effects module – partly, no doubt, because of reduced bandwidth in the recorders – but they definitely added a useful function.

In fact, I had intended to add tone and volume controls at this point, but the device refused point-blank to make any sound if anything other than a very low value resistor was put in the output path, I don’t know why.

In the end, I used 22Ω resistors to join the 4 outputs (two in series for the Sound Machine, which was a little louder than the others) and ran this straight to the speaker and output socket.  So, the final stage looked like this:

StyloSound - Output_3

The resistors are all 22Ω, as opposed to some other equally low value, simply because I had a pile of them which were going spare.

So: strange, but when I plugged it into my mixer, it  sounded fine, and the volume could be adjusted there.

*

The only thing left to do was to finish the case.  There was so much internal wiring and circuitry that the case had to be made 2.5″ deeper.  I constructed sides from an offcut piece of white plastic and superglued them in place – not especially neatly, it has to be said – with a little internal bracing.

top_IMG_1498
rside2_IMG_1494
back_IMG_1493*
This is what the StyloSound sounds like, controlled by ‘Bigfoot’:
01
Jun
13

The Taurus

The Taurus wasn’t a major project, but a handy companion piece to the Gemini, an earlier Stylophone modification.

The problem with the Gemini is that it has two voices, output in stereo, but, typical of the Stylophone, it has only the one speaker.  This means that some of its effects are only available via the stereo line out.

As a result of much past experimentation, I have many Stylophone bits left over.  To make the Taurus, which was to be a very simple external amplifier, I used an empty case, some spare grille material, two amplifier circuit boards and two speakers, all from S1 reissue versions of the instrument.

The Stylophone grille isn’t glued down, and can be removed from the inside by pushing out half a dozen lugs which hold it in place.  I did this first, cut a hole in the top of the case for the second speaker – vaguely matching the hole through which the original sounds – and refixed the grille.

The picture shows the second speaker glued in place, and the two amplifier boards connected to a new stereo input socket, the battery box and the speakers:

Taurus Inside DSCF0002

I wasn’t using any of the original keyboard, switch and socket parts, so I glued some spare grille sections inside the switch and socket holes and outside over the hole through which the keyboard is normally accessed.

A small tripod was attached to the base to enable the speakers to be angled for better distribution of the sound.  Decoration consisted of astrological symbols, in the style of the Gemini, and matching black and white bulls, front and back.

Front DSCF0003Reverse DSCF0005

It works well with the Gemini, which has its own volume and mix controls, but is a very basic unit indeed – no volume control, no on/off switch and no external power socket: it uses three AA batteries like the Gemini itself, and could be useful with other instruments needing a slight volume boost and not connected via a line out socket.

Gemini-Taurus DSCF0001

 

[Edit: the Taurus now has a volume control, which I should have put into start with.  This makes it much more practical to use.

Taurus Volume IMG_1512

As it uses a pair of Stylophone amp boards, I’ve done exactly the same as the Stylophone, and put a 10k log potentiometer at the input – in this case a dual, one for each channel].

02
May
13

UCreate Music, Part 2

In my first post on the Radica/Mattel UCreate, I mentioned adding In/Out connectors to enable the UCreate to be operated by external controls – e.g. joysticks – or the UCreate Button to be used to control other devices.

This post describes two of my devices which I modified for this purpose: the StyloSim and the Black Widow.

*

The StyloSim is a two-joystick controller, used for simple flight simulation games.  It has two medium-sized joysticks, which are very nice to operate, but no buttons.  Examining the controls using the [hid] object in PureData suggested that the chip it uses would support the use of buttons, but this function is not implemented.

StyloSim6sm

The essential task, then, with the StyloSim was to add two DB9 connectors, matching the connectors on the UCreate, so the UCreate’s effects could be controlled by the StyloSim, and whatever the StyloSim was used to control (at the moment, just one PureData program I’d written to add volume, filter and panning effects to an audio input) could also be controlled by the UCreate Button.

I checked to see that the ‘high’ and ‘low’ ends of the potentiometers in the StyloSim were both the same: they would have to be connected together to control the UCreate, but would also have to be left in a state where they correctly controlled the StyloSim chip.  They were connected, so I snipped the 6 wires between the circuit board and the potentiometers of the right-hand joystick (which I called ‘VR1′ and’VR2’).

The wires from the potentiometers were connected to the ‘Out’ socket, and the wires from the circuit board were connected to the identical pins of the ‘In socket’.  In this way, whatever else I connected, a DB9 lead connecting these two sockets would allow the StyloSim to function as normal.

In fact, I had another addition to make: the potentiometers would have no effect unless the UCreate ‘Hold’ switch was on.  As with the UCreate itself, I added a 3 way toggle switch, centre off, momentary in one direction, latching in the other, and connected this to the appropriate pins on the DB9 ‘Out’ socket.

Hold & LEDs IMG_1363

These connections were enough to ensure that, with the use of DB9 leads, the StyloSim could control the UCreate effects, and that the UCreate Button  – which had only one joystick – could control at least some of the things the StyloSim could control.

However, the UCreate also now had a ‘Volume Pedal’ output, which just required a potentiometer connected via a 3.5mm stereo socket.  As I had two more potentiometers available in the StyloSim, I connected one of these to a switched socket.  I used ‘VR4’, the up/down potentiometer of the left-hand joystick, as this was set not to return to centre when released, so would be very suitable for setting a volume level and then leaving it.  When nothing was plugged in, the joystick would remain connected to the circuit board inside the StyloSim; when a lead was plugged in, it would control the UCreate volume.

(In practice, unlike the volume pedal, the joystick – because of its limited travel, presumably – didn’t take the volume right down to zero, so was less effective than the pedal, but useful as long as complete silence wasn’t required).

I also made two more modifications, which weren’t strictly necessary, but which were not too difficult and, I felt, enhanced the design.

First of all, I chopped off the USB lead and added a socket instead.  This is only because I find it annoying to have fixed leads hanging off devices – it makes them awkward to carry about and store away.  Sometimes USB leads are small and fiddly, but at least they’re colour-coded.

(There is some variation in exactly which colours are used, however.  There’s supposed to be a convention, but as you can imagine, manufacturers find plenty of opportunity to use colour combinations of their own.  Those who are colour-blind – like me – have to be especially careful, but more often than not you can work out which lead is which.  Looking into a socket from the outside, 1, on the left-hand side, is +5v, and should have a red or orange wire connected to it; 2 is ‘Data -‘, and has a white or sometimes a yellow/gold wire; 3 is ‘Data +’ and has a green or sometimes grey wire; and 4 is Ground, with a Black or sometimes Blue or Brown wire.  I have come across other combinations, unfortunately, of which those using white or yellow for ground are the most annoying.  Often there are 5 wires, with an extra connection – frequently black – for the shield around the cables.

Looking into a plug, 4 is on the left-hand side and 1 is on the right.

I’ve mentioned before that I shouldn’t be using Type A sockets as the output of a device that’s being connected into a Type A socket – on, for example, a computer.  I should be using a Type B or mini USB socket; but this rule is to avoid connecting two devices together that both supply power, which might cause excess currents and start fires, and this isn’t going to happen with the devices I’m using – the StyloSim, for example, receives 5V from the computer, but doesn’t provide power of its own).

Finally, partly as an indicator that the connection with the UCreate had been properly made, partly because flashing lights are always good, I also added blue and red LEDs to the front of the StyloSim, and connected these to the relevant pins on the ‘Out’ socket.  These flash in time with the rhythm of the sounds from the UCreate, when the ‘Hold’ switch is on, so you can tell if the UCreate is ready to receive instructions.

These pictures show the new additions to the circuitry:

Inside IMG_1360

StyloSim rear IMG_1362

and this one shows the StyloSim in operation, controlling the UCreate, with the DB9 and 3.5mm connectors in place, the volume set fairly low, the ‘Hold’ switch on, and the LEDs flashing:

StyloSim in operation IMG_1364

*

Essentially, I did exactly the same to the Black Widow.  The big joystick on the right-hand side was connected to the DB9 ‘Out’ socket, and the ‘throttle’ on the left-hand side to the 3.5mm volume socket.

In this case, however, there were buttons available, so I was able to use the ‘F4’ button on the top of the joystick as a momentary ‘Hold’; for a latching Hold, I added an SPST switch at the bottom of the front panel, plus the two LEDs, which are illuminated when either Hold switch is activated.

Black Widow in operation IMG_1386

And this is the rear of the instrument – not that neat, but it all works:

Black Widow rear IMG_1387

*

As for the UCreate itself, I made three further changes – but these were more additions, rather than modifications:

1.  External power supply. I was pretty certain the UCreate would work with a 5v supply, and was about to use an old mobile phone charger for this purpose; but while I was looking through things I had lying about, I found a better quality one which I’d been given and which was rated at 5.5v, 350mA.  I replaced the connector with a 3.5mm mono plug to match the socket I’d installed in the UCreate, and it seemed to work perfectly, cutting out the battery supply when plugged in, and powering the device.

2.  Switch box.  It occurred to me that there might be occasions when, if I was using the Black Widow and the UCreate at the same time, it might be handy to be able to swap the joysticks quickly from controlling one thing to another, and a way of switching the DB9 leads from one device to the other would be useful.

I was looking into buying a DB9 switch box, which would have been about £5 – £6, but in the end I decided to be stingy and bought three DB9/DB25 adapters for about £4, as I found an unused two-way DB25 switch box amongst my stuff.  I had bought this for an as-yet-unrealised MIDI project: as this will probably remain unrealised for some while, I thought I might as well use it in the meantime.

DB9 to DB25

I did find a diagram on the internet to show how the DB9 pins were, according to the RS232 standard, allocated to pins on the DB25 connector, but it doesn’t really matter, as all 3 connections (in/out, A and B) will be the same.

Switchbox IMG_1389

The Black Widow ‘Out’ is connected to the ‘In/Out’ socket on the switch box; ‘Out A’ is connected back to the Black Widow ‘In’ socket; ‘Out B’ is connected to the ‘In’ socket of the UCreate.

3.  Feedback circuit.  As the UCreate has input and output sockets next to one another on the back, I thought a circuit that connected part of the output signal back into the input, in conjunction with some of the effects – for example, the filter or flanger – could potentially produce some interesting sounds.  Having just finished the modifications described in my first post and put everything back together, I decided to do this externally, so added two 3.5mm splitters to the line in and out, and connected them with a lead containing a volume control:

splitters & volume lead2

This allows some feedback sounds to be added to the linked samples or to sounds at the line or mic in sockets, and the amount can be limited by the volume control.

In Part 3 of the series, I look at the UCreate software.

19
Apr
13

UCreate Music, Part 1

This post concerns a very interesting device which was made a few years ago by Radica, a Mattel company.  It was manufactured for a very short time between 2009 and 2010, and supported only until 2011, but examples still appear on eBay, sometimes for very reasonable prices. I got mine for less than £10, which I thought was pretty good for a comparatively sophisticated machine.

ucreate box

Front low angle IMG_1320 Edit

The way it works is by playing loops, which you can choose from its memory – one each from 4 banks of 3 loops, in the categories ‘Back Beats’, ‘Riffs’, ‘Licks’ and ‘Runs’ – and apply effects to.  You can also record two of your own samples to add into the mix.

This is how you would normally use it (ignore the toggle switch and sockets on the left-hand side: this and other modifications I made are described later):

Controls IMG_1319

There are two reasons why the UCreate captured the imagination of electronic music-makers.  First of all, you could connect it to your home computer via a USB socket on the back and make use of software that would allow you to save recordings of songs, reorganise the loops and effects and download new loops from Mattel’s UCreate website.  I’ll return to this topic later.

The second thing was the range of 8 special effects, and the fact that these are available not only to the loops played back by the UCreate, but also to any audio source connected to the Mic or  Line in sockets.  The effects – referred to as ‘FX and Filters’ – comprise Tremolo, Distortion, Flanger, Phaser and Echo, a variable low-pass filter, and two unique and unusual effects called Forward/Reverse Looper and Rewind Spin Looper.  These work by recording very short samples and replaying them in various ways controlled by the user.

The way the effects are controlled is also highly unusual:  a large Button on the front panel can be pushed and tilted left/right and up/down to vary two parameters of the effect – for example left/right controls the speed of the flanger, up/down controls the depth.  If you find a setting you want to leave for a while, a ‘Hold’ button fixes it where you’ve set it until ‘Hold’ is pressed again.  The fact that the whole Button is lit up when in use  with flashing blue LEDs is just the icing on the cake.

Leaving aside the loop playback feature for the moment, this effectively makes the UCreate an inexpensive, but versatile multi-effects unit, playable in real time.  Although only one of the effects is available at a time, the Forward/Reverse Looper and Rewind Spin Looper in particular, together with the ability to control these in real time with the Big Button, makes the UCreate a useful and unconventional device to have.

I began by using the UCreate in this way, making just a couple of small modifications to it.

First, I added a socket for an external power source; then, as I had done with a number of my other instruments, I added banana sockets for connecting a larger external 8ohm speaker and a DPDT switch to cut out the internal speaker when this is in use.  There is a headphone/external speaker socket on the back of the Ucreate (which also cuts out the internal speaker when a plug is inserted), but this is a 3.5mm stereo socket, as you would find on a PC or mp3 player and is more suitable for use as a Line out.

These are the audio and USB sockets on the back of the device:

Rear sockets IMG_1358

Next, imagining a situation when both hands might be occupied in operating the loops and effects and not able to control the volume, I added a socket for an external volume pedal.  This was a 3.5mm stereo socket with internal switches, like the Line out socket.  I used a small size socket purely because of the lack of space inside the case.

On the small circuit board attached to the on/off/volume control, I broke the connection to the centre of the volume potentiometer and rewired it to the socket so that when nothing was plugged into it, it was connected directly to the main Ucreate circuit board, as originally designed; when the volume pedal was plugged in, the potentiometer in the volume pedal was added into the circuit.  This would enable the maximum volume to be set by the original volume control and the pedal to move between this and zero volume.

The pedal itself was simply a cheap second-hand Bespeco volume pedal.  I removed the original sockets and the circuit board inside and connected the potentiometer to a 3.5mm socket, wired in a similar way to the socket inside the Ucreate.  The tip was connected to the input from the Ucreate and the ‘high’ end of the potentiometer in the pedal, the sleeve to Ground and the ‘low’ end of the potentiometer, and the ring to the potentiometer wiper, the centre tag. (I should have built this before, as it would have been useful with many of the instruments I had made or modified, and I’ll have to consider retro-fitting sockets to them so it can be used).

Vol Pedal IMG_1326

I then decided to take a closer look at the big control Button.  I tried dismantling the mechanism, but couldn’t seem to get it completely apart.  This may have been because it was pressed or glued together after the circuit board was wired in, and I wasn’t going to risk breaking it by trying to prise it apart if it wasn’t meant to do that.

Button partial dissassembly IMG_1328

However, I got it apart far enough to see that it used a joystick for the left and right and up down movement.  This was mounted on a small PCB, and on the bottom of the PCB there were three momentary switches, set out in a triangle.  These were like the ones you often get on game controllers: they’re soft and squishy, and when you press them they join two contacts on the PCB; when you take your finger off, they spring back into shape and the connection is broken.

Button circuit board IMG_1333

All three switches were connected the same, and later experimentation showed that they had exactly the same function as the ‘Hold’ button, except they were momentary instead of latching.

This gave me two thoughts: first of all, with essentially a joystick and a momentary switch under it, it would be possible to use the UCreate’s Big Button to control another instrument or effect that normally used a joystick or two separate potentiometers; and secondly, there was no reason why the UCreate couldn’t be controlled by two potentiometers or an external joystick.

The way to do this would be to put the Button back and separate the connection between the UCreate’s main PCB and the Button PCB, and then route these connections elsewhere.

The link was made with a 9 way ribbon cable; the names of these 9 connections were printed on the main PCB, and even where this didn’t mean a lot, it was easy to follow the the tracks on the Button PCB and see what their functions were.  So I cut the cable.

From top to bottom, the connections were:

VCC_33 – which connected to one side of all three switches

IOA15 – connected to the other side of the three switches

GND_ADCVCC33 – connected to one end of the two joystick potentiometers (the ‘low’ end, presumably)

LINE 3 – the centre tag of one of the potentiometers (the ‘up/down’ one, which I called ‘Pot 2’)

ADCPVCC33 – the other end (‘high’ end) of both potentiometers

LINE 2 – the centre tag of the other (‘left/right’) potentimeter which I called ‘Pot 1’

R154_1 – one side of one of pair of surface-mounted blue LEDs on the Button PCB

R68_1 – one side of the other LED

V BAT – the other side of both LEDs (+6v, presumably)

Essentially what I did was to connect the end of the ribbon cable that came from the main PCB directly to a DB9 connector on the back on the case.  This was marked ‘In’.  The other end of the ribbon cable, the one from the Button PCB, was connected to another DB9 connector, marked ‘Out’.

In this way, if you wanted to control the UCreate from another device – a larger joystick, perhaps – all you would need to do was connect it to the DB9 ‘In’ socket; if you wanted to control another device with the Big Button, you would connect the other device to the DB9 ‘Out’ socket; and to use the UCreate as normal, just connect the two sockets together with a DB9 cable.

In order to make space for the DB9 sockets, which are quite big, I had to remove part of the bottom half of the case, which stuck up inside:

Inside sawing IMG_1341

I think this was probably a carrying handle, but I didn’t think I needed it, so I sawed it off and created a lot more space in the back of the case.

In fact, I didn’t connect the Button directly to the ‘Out’ socket.  Although the Button works brilliantly well for the Reverse and Rewind ‘stuttering’ or ‘scratching’ effects, there was a lack of precision when it came to such things as the filter cut-off frequency, speed and depth of flanging, and so forth.  Apart from anything else, joysticks don’t usually use much of the possible travel of  an ordinary potentiometer, so there was also a restricted range over which the Button was operating.

So I decide to squeeze a couple of potentiometers into the case, which would be selectable in place of the Button.  The two connections for the centre tags of the potentiometers (‘Line 2’ and ‘Line 3’)  coming from the Button PCB went to one side of a DPDT switch, and the poles went to the DB9 ‘Out’ socket.  The wires from the other side of the DPDT switch went to the centre tags of two potentiometers, which I squeezed in the front of the case.  The two connections for the ends of the potentiometers went to the potentiometers and to the socket.

In the event, I also added a 10k preset, set at about halfway, in the circuit at the potentometers’ ‘bottom’ end: it seemed to me that some parameters – e.g. the filter cut-off frequency, and the volume pot when using the tremolo effect – were going too low, at the expense of effects that could be obtained with higher resistance.

The way the UCreate works, the potentiometers  – and the potentiometers under the Button, come to that – have no effect unless one of the ‘Hold’ buttons is pressed, so I needed to add a momentary button, preferably somewhere near the potentiometers.  There was just about room, and what I decided to use was a toggle switch with a centre off position, momentary on in one direction, latching on in the other.  This would enable me to engage the momentary switch, adjust a potentiometer, then when I had exactly the sound I wanted, latch the switch on.  So the two connections for the switch went both to the DB9 socket and to this new switch.

In fact, they went to a third place: a standard (1/4″ or 6.35mm) mono jack socket to which a ‘Hold’ footswitch could be attached.  I used a standard size jack in this instance because I had some nice ready-made footswitches: they’re apparently sold for use with tattoo machines, but come with standard jacks attached, which is very handy.

Hold Pedal IMG_1356

So that’s how I modified my UCreate, producing a versatile and quite easy to use multi-effects device.  This picture summarises most of the changes I made:

Inside closeup w. captions IMG_1346

I don’t know if they’re all the same, but the grille on the front of mine came off very easily, so I took the opportunity to remind myself of what the 8 effects are, and what order they come in.

Front grille off IMG_1324

The front and back of the device now look like this:

Front and back IMG_1352

and here’s what it looks like in operation:

In operation 2 IMG_1348

Read the UCreate User Manual here: N9496 UCreate Music Manual 1L-English

In Part 2 of this series of articles I describe modifications made to some other devices in order to work with the UCreate.

23
Nov
12

Stylophones 4 – The Stylophone 350S, Part 2: Simple mods

After opening my 350S and giving it a good clean, I decided to carry out a few simple mods before putting it back together again.

The first thing I did was to detach the external connections to the two circuit boards to make it easier to take everything apart and get at.  These connections were:

  • keyboard
  • speaker
  • power
  • styluses
  • pitch

I carefully desoldered the wires, and replaced them with 2 or 3-way Molex connectors, like these:

Molex connectors IMG_1230

*

At this stage I decided not to make any further modifications to the keyboard.  The keyboard PCB now plugs into the main circuit board and is much easier to remove for cleaning and for further potential modifications.

This picture shows the front and back of the keyboard PCB with a 2-way Molex socket fitted, connecting top and bottom of the chain of resistors which produce the different notes:

Keyboard PCB complete

*

In the case of the speaker wires, the Molex connector makes it easier to move the main circuit board around while working on it, as the wires are no longer than absolutely necessary and the speaker is firmly fixed to the top half of the Stylophone body.

The modification I made to this – which I’ve done with several of my instruments recently – was to add a switch to swap between the internal speaker and a larger external speaker (as described here).  I chose a large DPDT rocker switch, which seemed to be in keeping with the 350S’s style.  I don’t know how necessary it was, but as the internal speaker is 35Ω and the external speaker is 8Ω , I added a 3W 27Ω resistor in series with the output, which is a pair of 4mm banana plug sockets.

*

As far as power was concerned, I first wanted to replace the large PP9 batteries.  Not only are these heavy and expensive, but they take up a lot of room inside the Stylophone case, which might be needed to house extra circuitry.  So what I decided to do at this stage was to replace them with something more practical: rechargeable PP3’s.

I wasn’t sure these would be powerful enough to allow the 350S to function properly, but I exchanged the PP9 wiring for PP3-sized battery clips and everything seemed to be working.  I then looked for some PP3 holders that would provide a more permanent fixture for the batteries.  This type seemed to fit the bill:

There was just enough room to fit these side by side into one of the covers formerly used for access to the PP9’s, each one attached with 4 small nuts and bolts.  Although opened from the outside, these battery holders occupy the internal space originally taken up by one of the PP9’s.

Battery holder panel complete

Clips for the two PP3’s are connected to the power Molex connector via a 3.5mm mono socket with an integral switch, so that anything plugged into the socket automatically disconnects the internal batteries.

Battery clips IMG_1220

Later, the socket might be used for an 18v power supply, but for the time being I attached the discarded PP9 wiring and clips to a 3.5mm plug, so that PP9’s can still be used, but don’t have to be installed inside the body of the 350S.

*

Unlike the regular Stylophone, the 350S has two styluses: one for normal playing, sounding continuously for as long as the stylus is in contact with the keyboard; and one for ‘Reiteration’ mode – with the appropriate switch selected – producing a fast or slow series of pulses, in imitation of a banjo or mandolin, on which it’s common to pluck a single note repeatedly.

However, I had found while modifying normal stylophones, that it was sometimes handy to have two styluses, one in each hand, for playing quicker or more intricate passages; so I decided to rewire the two existing styluses as standard, and add two extra ones for Reiteration mode.

With the Molex connectors in place, it was easy to wire all four styluses up, but not so easy to find a way to secure the extra two to the Stylophone in such a way that they would be easy to reach.  In the end, I used a pair of clips like this, sold on eBay as penholders and meant, I think, to clip onto a pocket:

Pen holder

I had some spare white styluses, so the ‘normal’ styluses are black, and the ‘reiteration’ styluses are white.  I attached a holder each side of the Stylophone in which the white styluses sit.  The long wires attached to these can be pushed inside the body of the Stylophone when not in use.

I wasn’t able to find an exact match for the wire used by Dübreq for attaching the styluses.  It’s only just over 2mm in diameter, and very flexible; there are no more than 10 or 11 strands of wire inside quite a thick outer layer, and a non-conductive cord running along the length of it, on the inside – presumably for strengthening.  If I ever find out where to get it, I’ll add it as an Edit to this post: in the meantime I had to make do with a standard multi-stranded white ‘hook-up’ wire of about the same width.

*

Dealing with the pitch of the 350S didn’t involve detaching external wires, in fact, but I added a 3-way Molex connector to the tuning control to make it easier to experiment with.

Unlike some of my previous Stylophone mods, I wasn’t looking for extreme pitch changes this time, but something more along the lines of a synth modulation wheel.  Strangely, these seem to be very rare, but I found one produced by the German company Doepfer, described here.  It comes as a kit of parts, like this:

Doepfer Mod Wheel Kit

The pot supplied with it is a 10k, which has a knurled shaft fitting tightly inside the hole in the ‘half-wheel’.

I  wired the wheel in parallel with the existing tuning control, and its effectiveness depended on three things:

1.  The setting of the tuning control: the higher it was set, the less variation produced by the wheel.  Not much I could do about this, as the tuning control is used to set the 350S to the correct pitch, compared to other instruments.  If it proves a problem, it could perhaps be solved in the future by a slight adjustment to the keyboard resistor chain.

2.  The value of the pot.  I found that a 2.5k pot was the most effective, but couldn’t find one with a shaft compatible with the Doepfer wheel.  So I added some 10k resistors in parallel with the 10k pot.  Originally I added 3, which would have made the pot 2.5k, but 2 seemed to be enough (3.3k), and took up less space, so I left it at that.

3. The part of the potentiometer track covered by movement of the wheel.  The wheel wasn’t able to move the wiper of the potentiometer round the whole track – which is normal for mod wheels, joysticks, etc.  It took a bit of experimentation to find the right place, which essentially meant turning the potentiometer to exactly the right position before attaching the wheel.  It needed to be at zero when the wheel was deflected fully down, and eventually I found the right place, wired leads and a Molex plug to it and fixed it in place with small nuts and bolts.

The whole construction took the place previously occupied by the left-hand PP9, with the wheel appearing through a slot in the top of the 350S .  The Doepfer kit cost about £10, so it was a bit of an extravagance, and something like it could probably be rigged up more cheaply.  However, it adds an interesting feature to the 350S which it never had before.

This picture shows the pitch wheel assembly in place and also, in the background, the speaker switch and banana sockets.

Speaker switch & wheel IMG_1219

This picture shows the top half of the 350S body, with the new components and the Molex connectors in place, with the circuit boards removed:

Inside no PCBs IMG_1218

*

After fitting everything, it was time to put the 350S back together.

The first item to go back into place was the main PCB.  This picture shows the board in position, with the 6 fixing screws marked:

Main PCB in place IMG_1233

Next, the Keyboard PCB was installed.  The 4 fixing screws are marked:

Main & Keyboard PCBs in place IMG_1234

Before the bottom half of the 350S body was attached, the PP3 battery clips were fed into the battery holders:

Inserting battery clips IMG_1235

The two halves of the body were fitted together and batteries inserted:

Battery inserted IMG_1237

Finished and ready to go!  The underside of the 350S now looks like this:

Back with battery holders IMG_1221

and the front and back like this:

Front & Back finished IMG_1240

This gives a good view of the power socket on the back left, as you look at it; the speaker switch and sockets on the back right; the pitch wheel on the top on the right; and the white ‘reiteration’ styluses in their holders.

*

Finally, with the 350S back together and in operation, I looked at the suggested external addition, a volume pedal.  According to the 350S manual, this would replace the photo control, and adjust not only the volume, but also the waa filter and the vibrato depth.

The manual recommends a ‘standard Foot Pedal’: but what was a standard foot pedal in the 1970s is not what we might consider a standard foot pedal – or ‘expression’ pedal – these days.  What’s required here is a 50k-100k log pot, which plugs into the 350S via a 6.35mm (1/4″) mono jack plug.

I had an old volume pedal (probably dating almost from that era!) which I was able to adapt.  The original cable was crackly and the pot was scratchy, so I shortened the cable to remove the section that was obviously damaged inside, and replaced the pot.

I didn’t have a 47k or 50k to experiment with, so I used a 100k, but that seemed to be fine.  The only oddity is that the ‘waa’ works backwards, in that the filter is at the ‘high end’ with the heel down – as compared to, for example, a guitar wah pedal, where heel-down is the low end, and toe-down is the high end.  I tried putting a polarity change switch in the pedal, but that didn’t work, as the pedal mechanism – just the same as the pitch wheel described earlier – is set to reach its minimum when the heel is fully down, and doesn’t cover the full travel of the pot, so when the two ends of the pot were swapped, the pedal wasn’t reaching zero, which it needed to do to produce the full ‘waa’ effect.  I’ll just have to get used to it.

After playing the instrument for a while, I noticed that one of the switches was a bit crackly, so this is something I might tackle later on, together with a couple more mods I have in mind.

12
Oct
12

Bigfoot – automatic/remote stylophone control, Part 2

As described in Bigfoot, Part 1, I was  constructing a device to play a modified stylophone remotely and automatically.  Using a 16 way analogue switch, the 24-pin 4067 chip, I designed a device where any one of 15 intervals on a 2-octave tonic sol-fa scale would be triggered by changing the chip’s 4-bit binary input.

First of all, I had used a physical control, a 16 position binary or hexadecimal rotary controller; what  I needed next to find was chips that could be made to output sequences of 4-bit binary numbers.

There are several of these, and I went for the 4516, which is a pre-settable binary counter.  It can, if left alone, repeatedly count upwards from 0 – 15, outputting numbers in binary form (‘0 0 0 0’ to ‘1 1 1 1’) on the pins marked ‘Q1’ to ‘Q4’ in the diagram below at the speed of a pulse connected to its clock input (Pin 15); or downwards from 15 – 0.  But by pre-setting a certain number, in binary form, on 4 extra binary inputs, marked ‘P1’ – ‘P4’ in the diagram, it can also be made to count upwards from this number to 15; or downwards from this number to 0.

This is how the 4516 is usually represented in circuits:

Q1 – Q4, as mentioned above, are the outputs, and P1 – P4 are the inputs for the number the count starts from, both in the form of a binary number.  The ‘Preset Enable’, pin 1, is usually held low (0v): when it’s taken high (+v) the number on the inputs P1 – P4 is loaded in and the next count starts from that number.  ‘Preset Enable’ is sometimes referred to as ‘Load’ for this reason.  The ‘Carry Out’ is normally high, but goes low when the count ends.

The ability to count downwards from a set number would be useful for an arpeggiator, which could be set to repeat a sequence with a length of 2 – 16 notes, using the rotary encoder, described in Part 1, connected to the 4 binary inputs to preset the sequence length.

The circuit for this device was extremely simple, requiring only the rotary encoder, a momentary switch to tell the 4516 to load the sequence length number, an on/off switch and two inverters from a 40106 (which has 6 in it altogether) .  One of the inverters was connected as an oscillator, which was connected to the 4516’s Clock input: this determines the speed at which notes sound; the other inverter was connected between the ‘Carry Out’ and ‘Preset Enable’ pins: the ‘Carry Out’ is normally high, so the inverter keeps the ‘Preset Enable’ low; when the count ends the ‘Carry Out’ goes low and the inverter sends a ‘high’ pulse to the Preset Enable, reloading the start number.

Encoder_4516

Pin 10 is connected to 0v in this circuit, which tells the 4516 to count down, not up: this was the easiest way to make sure it counted the right number of notes in the sequence.

In fact, counting up or down would result  only in a scale or part of a scale being played, so I made the output a bit more interesting by reversing the 4 outputs.  Instead of connecting the A output of the 4516 to the A input of the 4067, the B output to the B input, etc., I connected it so that A B C D were connected D C B A.  In essence this meant that consecutive notes in the sequence would not be consecutive notes in the scale, which I thought would be more interesting.

This produced method 2 of controlling the Stylophone: automatic arpeggiation.

*

The third method of controlling the Stylophone automatically used 3 more of the inverters in the 40106 which had been used for the 4516 clock and ‘Carry Out’ inverter.  The inverters were wired as oscillators.

This was the idea that came from the ‘Slacker Melody Generator’, described at http://electro-music.com/forum/viewtopic.php?t=27239&postorder=asc&start=50.  Each of the 4 oscillators is connected to one of the 4 inputs of the 4067; each runs at a different speed, changing the value on that input from low to high, or 0 to 1.  The different successive combinations of 0s and 1s produces a random melody, which can be changed by adjusting the speed of the oscillators, increasing or decreasing the rate at which each particular input changes from ‘1’ to ‘0’.

40106

The reason the four oscillators have two capacitors each is simply because the original circuit I used suggested values of 220n; I soldered these in place, but the oscillators seemed to run too fast for my liking, and it was easier to add new ones in parallel than take the old ones out and replace them.  The result of putting capacitors in parallel is the opposite of putting resistors in parallel – instead of the overall value decreasing, it increases; the capacitance is larger and the oscillators run slower.

Having put the 4067 and the five DPDT switches in place, I then had to connect the relevant input/outputs to 24 different resistors, in a chain (or ladder) like the original one inside the stylophone.  I suppose it would have been possible to calculate the exact resistances, but I had some time ago obtained a hundred 10k presets for about 7p each, for exactly this kind of situation, so decided to use those and tune it by ear.

This took some time, but at the end of it I had a substitute resistor chain for the SoftPot Stylophone and some methods of controlling it automatically.

*

It then occurred to me that with this arrangement, all this extravagance could only control one stylophone at a time, so I had a think about how to connect more instruments (and possibly instruments other than stylophones!).

The way to do it, it seemed to me, was to use the binary inputs to the 4067 as an output: any device could then be controlled, just by installing the 4067 and the five ‘major/minor’ switches in it – or perhaps some other suitable arrangement.

So I added two 5-pin DIN sockets as outputs, the five terminals being A, B, C, D and 0v.  Each of the four A, B, C, D outputs was buffered, using four of the six buffers in a 4050.  The 4050 is similar to its sister chip, the more well-known 4049; but whereas the 4049 inverts its outputs, the 4050 doesn’t.  This chip has even cleverer properties, which I will be using in a later project, but here I used it to ensure the binary outputs were of sufficient strength to make their way through a connecting cable and satisfactorily operate external circuitry.

I also added at this stage Clock In and Clock Out sockets, which would enable Bigfoot to set the tempo of a piece involving different instruments, or follow the tempo set elsewhere.  These two input/outputs passed through the remaining two buffers on the 4050.

The final thing was to add two more 5-pin DIN sockets, this time as inputs.  This would enable external circuitry to control the 4067s.  I had several more ideas of suitable external devices which could be used to do this, and I hope to be able to get around to making these quite soon.

The only other unusual component needed to get all this to work was a suitable master switch, to select the various external and internal inputs to the 4067s.  This had to have 4 poles – the A, B, C, D binary inputs – and 5 positions.  4 pole, 3 way rotary switches are easy to come by, but 4 pole, 4 or 5 way are not.  Fortunately, I was able to source a 4 pole, 5 way switch on eBay from a supplier in Hong Kong for just a couple of quid, so everything was in place.

With a circuit like this – just a handful of chips and a few external components – you either get a neatly laid out PCB or a rats’ nest of wiring.  I ended up with a rats’ nest of wiring . . . however, it worked, even when crammed into the case, with the addition of an extra section underneath the ‘big foot’ I had selected.

This picture shows the two binary input sockets on the left.  The 5 way switch is the knob on the front of the Bigfoot, just the right of centre in this picture.

Bigfoot Left DSCF0002

Due to a certain amount of experimentation along the way, some changes of mind about the functions, and some difficulties in getting all the switches and sockets to fit, there were some extraneous holes which I had drilled in the case.  The plastic frogs are there to hide the holes.  I also added a square of velcro on the back where I could attach a battery holder, as I had done with a number of previous projects.

DSCF0004*

This is what Bigfoot sounds like, controlling the SoftPot Stylophone and the StyloSound at the same time:

 [Edit: there is now a link to a short video of the Bigfoot in action at the bottom of this page].

12
Oct
12

Bigfoot – automatic/remote stylophone control, Part 1

I’d made enough instruments for the time being, and it was time to construct some automatic controllers – sequencers, arpeggiators and the like – as an alternative to playing them by hand.

When I made the SoftPot Stylophone, I had added a socket which allowed external circuitry to replace the chain of resistors which govern the pitch of the instrument.  This project was to make a device which would be able to use this feature to operate the SoftPot Stylophone remotely, and this rather blurry photograph shows the result – Bigfoot:

DSCF0005

I got the inspiration from several places: the arpeggiator and sequencer from Fun with Sea-Mosshttp://milkcrate.com.au/_other/sea-moss/; the melodygenerator by Slacker described on the electro-music.com forum: http://electro-music.com/forum/viewtopic.php?t=27239&postorder=asc&start=50; and the Intro to Lunetta Synths at https://docs.google.com/document/edit?id=1V9qerry_PsXTZqt_UDx7C-wcuMe_6_gyy6M_MyAgQoA&pli=1,  All these sites are full of great ideas and practical examples.

The main chip used in the circuits described above is a 4051, which is basically a single-pole 8-way switch.  It’s usually depicted in circuits like this:

The way it works is like this: it’s an analogue switch, not a digital switch, meaning you can connect anything you like to the pole (pin 3, marked Z in the diagram) and the 8 switch input/outputs (on the right-hand side, marked Y0 – Y7).  It doesn’t have to be logic high or logic low (i.e. +v or 0v) , it can be any voltage, an audio signal, anything – just like a physical switch.  Any one of the 8 input/outputs can be connected – one at a time – to the pole, not by turning a physical switch, but by the logic high or logic low status of the 3 ‘Select’ inputs (pins 9, 10 and 11, marked S1 – S3).

You can have every combination of logic high and logic low on the three Select inputs, ranging from 0v on all of them, 0v on one of the three and +v on two of them, +v on two of them and 0v on one, or +v on all of them.   There are eight possible variations, starting with 0v on all of them, which you could represent as ‘0 0 0’ or the binary equivalent of the number zero, to +v on all them, which could be represented as ‘1 1 1’ or the binary equivalent of the number 7.

If you feed 0v to all three of the Select inputs, or ‘0 0 0’, this is lowest possible binary number, so the lowest or first input/output is connected to the pole (Y0, pin 13); if you connect, say the one on pin 9 (S3) to +v and the other two to 0v, this would be the binary number ‘1 0 0’, the equivalent of the number 4.  Because the sequence starts with ‘0 0 0’ , or zero, feeding in ‘1 0 0’  connects the 5th rather than 4th input/output to the pole (Y4, pin 1).  By connecting all the Select inputs to +v, or ‘1 1 1’ (the number 7), the 8th input/output is connected to the pole (Y7, pin 4).

In the circuits I looked at, a common type of connection would be to have the pole connected to the part of an oscillator circuit that determines the pitch, and 8 input/outputs connected to different value resistors.  This would mean that a different resistance would be connected to the oscillator and a different pitch would be sounded when each of the 8 input/outputs was connected to the pole.

You could determine whether each of the Select inputs was a ‘1’ or a ‘0’  with  three 2 way switches, +v one way, 0v the other way, and change the notes by moving different switches up and down.  But this would be rather tedious.  By adding a circuit that automatically changed the ‘1’s and ‘0’s, you have a melody generator, arpeggiator or sequencer.

This was the kind of circuit I was after.

However, 8 notes was bit restricted.  Not restricted because there are 12 notes in one octave, though: I reasoned that you could make life easier for yourself by only allowing notes in a single scale – the ‘do’, ‘re’, ‘mi’ approach so succinctly captured in the Rodgers and Hammerstein song from The Sound of Music (‘Do a deer, a female deer/Re, a drop of golden sun’, etc.).  There are only 8 notes in a  ‘do’, ‘re’, ‘mi’ scale, including the next ‘do’ up from the one you started from.  If you just use those, you’ll never get an ‘out of tune’ note in your arpeggio or sequence.

The proper name for the ‘do’, ‘re’, ‘mi’ system, by the way, is ‘tonic sol-fa’, and was invented here in East Anglia by Sarah Ann Glover of Norwich, who lived from 1785 to 1867.  This 1868 woodcut shows Sarah Ann teaching ‘do’, ‘re’, ‘mi’ to the musical children of Norfolk:

(Why this public domain picture  is held by Music Department of the Bibliothèque National de France is not adequately explained by the Wikipedia, where I found it.  I suppose the fame of ‘do’, ‘re’, ‘mi’ is international).

No, it was restricted instead because the SoftPot Stylophone has 12 ‘do’, ‘re’, ‘mi’ steps from the bottom of the keyboard to the top – and in any case could be made to produce notes outside the range of the built-in keyboard.

So I decided I needed 16 steps (2 octaves, including ‘do’ two octaves up from the start), and found a chip, the 4067, to do the job.  The 4067 is a single-pole switch like the 4051, but with 16 switches instead of 8.  The only way it differs in operation from the 4051 is that it requires 4 Select inputs in order to go all the way from ‘0 0 0 0’ (zero, meaning the first input/output is connected) to ‘1 1 1 1’ (15, meaning the 16th input/output is connected).

The 4067 usually appears in circuits like this:

It’s very similar to the 4051: there’s a Pole (pin 1, marked Z); 16, instead of 8, input/outputs (right-hand side, marked Y0 – Y15); and 4, instead of 3, Select inputs (pins 10. 11, 13 and 14, marked S0 – S3).

I also decided to make things slightly more complicated by considering alternative scales.  If you follow the ‘do’, ‘re’, ‘mi’ scale of the Rogers and Hammerstein song, this is a major scale.  If, on the other hand, you wanted to play, for example, a minor scale, you would find that ‘mi’, sometimes ‘la’ and sometimes ‘ti’ have to be changed to be a semitone lower.  And occasionally you might feel like making ‘re’ and ‘so’ lower as well.  (‘Do’ and ‘fa’ can be left alone!).

I’ll explain in a minute exactly what scales I had in mind when doing this, and where I got the idea from, but adding the ability to sharpen or flatten certain notes of  the scale meant that I needed 25 notes instead of 15, so the 4067 was wired up like this:

4067 1 Edit

The notes depicted are the notes that would be used in the key of A.  Since the SoftPot Stylophone has a tuning control (in fact two tuning controls!) on it, it can be made to play in any key, not just A; the circuit here doesn’t need to be changed, only the tuning on the SoftPot Stylophone itself.

Each of the 16 outputs of the 4067 is connected to a resistor in a chain.  The top of the chain is connected to the tip of a 3 way (‘stereo’) 3.5mm socket; the bottom of the chain is connected to the ring, and the sleeve is connected to pin 1 of the 4067 – the pole of the 16-way switch.  When plugged in, it takes the place of the Stylophone’s own resistor chain.

Note that switches allow you to choose between 1) major and minor 2nd (‘re’); 2) major and minor 3rd (‘mi’); 3) major and minor 5th (‘so’); 4) major and minor 6th (‘la’); and 5) major and minor 7th (‘ti’), as you see fit.  C1/C#1 and C2/C#2, D#1/E1 and D#2/E2 etc. use the same switch, so there are 5 of these switches, not 10.

The reason I chose to do it this way is because of an extremely interesting article – series of articles, actually – which I read on The Tonal Centre website, written by Andrew Milne.  I’m not in the slightest bit concerned that the theory described there is ‘unconventional and some of the concepts . . . quite novel’, as it seems to me to make perfect sense, and presents a coherent view of scales and chords which I’ve found quite easy to understand, and useful to use.  Furthermore, Milne’s motives for writing the articles are ones with which I would hope none of my readers could disagree: ‘not for theory to be an intellectual straight-jacket which smothers spontaneity, but as a springboard for creativity and, even more importantly, as a foundation for exploration’.

Essentially, the articles do precisely as the author says in his introduction: ‘convince you that there is a lot more for the tonal composer to experiment with . . . than just the major and the minor scale.’

I can’t explain everything in the articles because a) there is too much, and b) I don’t understand it all; but essentially, the points I want to draw attention to are these:

1. What constitutes a useful and versatile scale?

A scale should constitute ‘a unified collection of notes – a selection which is in some sense complete and to which any addition is heard to be extraneous’.

2.  What makes a scale useful as a melodic resource?

A scale should be ‘reasonably smooth and even, without sudden gaps which sound as if a note has been omitted, or sudden concentrations of notes which sound as if an extraneous note has been added’.

3.  What makes a scale useful as a harmonic resource?

Because three-note major and minor chords are the basis of our kind of western music (like C-E-G and C-Eb-G), a scale shouldn’t have any notes which aren’t part of a three-note major or minor chord.

Of all possible scales there are only five prime scales which satisfy Milne’s criteria, as above. (These are the main criteria, but see the full article for a couple of others).

All of these scales contain, as it happens, seven notes, and these are clearly the most useful and versatile scales to use.  This was good news for me, as the Bigfoot would inevitably use 7-note scales.

There are 8 different scales altogether in Milne’s system, not just 5, because of  differences between major and minor, and so on, and these 8 variations of the 5 ‘prime scales’ (in the key of C) are:

1.  The diatonic scale, major and ‘aeolian’:

C-D-E-F-G-A-B

C-D-Eb-F-G-Ab-Bb

2.  The harmonic minor scale:

C-D-Eb-F-G-Ab-B

3. The harmonic major scale:

C-D-E-F-G-Ab-B

4.  The melodic scale, major and minor:

C-D-E-F-G-Ab-Bb

C-D-Eb-F-G-A-B

5.  The double harmonic scale, major and minor:

C-Db-E-F-G-Ab-B

C-D-Eb-F#-G-Ab-B

So, there are 8 different scales you can use, which all allow you to make interesting melodies and chords.  Each one has its own ‘character’, and some are much more commonly used than others.

This series of articles seemed to me when I came across it to be an extremely good guide to useful scales, and could be a help to anyone: you could use the description above to work out what scale or scales you commonly use, and then try writing a composition or improvising a solo using a completely different one.  There’s bound to be at least one you’ve never thought of using before!

Bigfoot allows the 2nd, 3rd, 5th, 6th and 7th (D, E, G, A, B in the above examples) to be individually adjusted, so arpeggios and sequences in all – well, almost all! – of these scales are possible.  The double harmonic minor isn’t possible because Bigfoot can’t produce F# and G at the same time; but 7 out of 8 isn’t bad!

So, 16 individual intervals are available  from the Bigfoot, spread over two octaves; the tonic is repeated 3 times, at 3 octaves; the 4th is repeated twice, at two different octaves; the other 10 notes are switchable between a ‘normal’ or ‘flattened’ version, which is semitone lower.

Hang on, that’s only 15 intervals . . . Well, since all 16 Select input combinations from ‘0 0 0 0’ to ‘1 1 1 1’ could be used to produce notes, there might in some circumstances be no way of stopping the Stylophone from sounding; so what I did was to start with ‘0 0 0 1’ (the second output) and make that the lowest note, reserving ‘0 0 0 0’ (the first output) for a rest where no note would sound.  I added a switch so that the first and second inputs could be connected together for those situations when this would be better.

I also added a START/STOP switch, which is what pin 15 of the 4067 does: if connected to +v it stops, and all the switches are disconnected, regardless of the state of the Select inputs; if pin 15 is connected to 0v the switches start to work.  (The 4051 also has this feature).

In practice, I actually installed a second 4067, with the two 4067’s being connected only at the 4 Select inputs (pins 10, 11, 13 and 14).  I wanted to have an LED indication of which switch was connected, and had to separate this function from the resistor chain that produced the notes.

So the pole pin of the second 4067 was connected to +9v via two 1k resistors [not one, as shown in the diagram], and each of the 16 outputs was connected to a green LED (matching the green case the circuit was built into).

4067 2

In order to test the LEDs – and later to test the notes which were being produced – I needed some way of connecting exactly the right input/output to the pole of the switch, so I would know I was adjusting the right preset.  This meant feeding exactly the right combination of  +v (‘1’s) and 0v (‘0’s) to the Select inputs, to get exactly the right output.

I considered four 2-way switches, +v one way, 0v the other way, and changing the notes by moving different switches up and down, as I described before – but it turns out there is a device which does this job very simply, just like turning a rotary switch: a 4 bit binary (sometimes called hex) rotary encoder.  I wouldn’t say these are extremely easy to come by, but this is the one I got:  http://uk.mouser.com/ProductDetail/Alpha-Taiwan/RE2001F-40E2-20F-4B/?qs=yA6kp8fx8Y4fjZ7sDt2l6A%3d%3d.

rotary encoder2

(The above picture shows a typical rotary encoder made by Alpha Electronics.  RS online sell a couple, but looking at the product details, I don’t think the connections of the ‘Code 033’ version they sell is right.  There are lots of 2 bit encoders, and lots of encoders which are not binary or hex.  They won’t work – it has to be 4 bit binary with 16 positions, starting with ‘0 0 0 0’ at position 1 and stepping through the binary numbers 1 – 15, ending up at ‘1 1 1 1’ at position 16. These are referred to as ‘hex’ because the hexadecimal system has 16 numbers in it [usually written as ‘0 1 2 3 4 5 6 7 8 9 A B C D E F’ – a more user-friendly way of depicting ‘0 0 0 0’ to ‘1 1 1 1’]).

I needed to use the encoder for another part of the circuit, which I’ll come to later, but for the time being its 4 outputs were connected directly to the 4 Select inputs, ‘A B C D’, of the 4067s.  Its other connection, ‘Common’, was connected to + volts.  To test it, I used  4 LEDs, and could see that turning it from position 1 to position 16, it automatically output the binary numbers in order from ‘0 0 0 0’ to ‘1 1 1 1’.

It’s worth mentioning an important point, to avoid later confusion, which is that ‘D’ is actually the bit on the left in a binary number such as ‘1 1 0 0’, and ‘A’ is the bit on the right.  You might sometimes see ‘D’ referred to as the ‘Most Significant Bit’ (or ‘MSB’) and ‘A’ as the ‘Least Significant Bit’ (‘LSB’).  That means the number sequence goes like this:

D  C  B  A

0  0  0  0

0  0  0  1

0  0  1  0

0  0  1  1

0  1  0  0

etc.

The other thing about rotary encoders is that they don’t usually have a stop, they just go round and round.  This is fairly useless if you need to know where ‘1’ is, or where ’16’ is, and this is the main reason why I decided to incorporate the LEDs as a visual indication.  The other reason is that sequencers and so forth really ought to have flashing lights on them.

The rotary encoder is the knob on the right-hand side of the Bigfoot, just to the right of centre in this picture:

DSCF0003

I glued the LEDs in place on the top and connected up the rotary switch.  Sure enough, with each turn the LEDs lit up one by one, one at a time, and now it was possible to tell which was position 1, which was position 2, etc.

Not only that, with the lack of a stop at 1 and 16 – which you would expect with a normal rotary switch – if nothing else I had Method 1 of controlling the Stylophone remotely: a manual method of arpeggiation by spinning the encoder backwards and forwards! . . .

. . . Entertaining, but not the automatic method I was looking for, however, so I moved on to Part 2 of the construction.

23
Aug
12

BigBoy BeatBox

You’ve got a Stylophone, you’ve got a Stylophone Beatbox – but don’t you sometimes wish the two could be combined into one instrument? . . .

Well, now that wish has become reality, with the ‘BigBoy BeatBox’: two great Stylophone products in one!

New Front IMG_1128

As the picture suggests, the BigBoy BeatBox is, in fact, two great Stylophone products literally glued and bolted together, with some of their internal circuitry combined.  The way it was created was like this:

1.  The Stylophone

The Stylophone half of the instrument is, in fact, a recreation of the original ‘Big Boy’ – a regular Stylophone S1 inside a Beatbox case.  As mentioned in an edit to the original post here, I managed to inflict terminal damage on the ‘Big Boy’ by reckless experimentation.  I normally do this before finishing an instrument, this time I contrived to do it afterwards . . . so the first thing I had to do was remove and replace the electronics with a new donor Stylophone I had lying around.

The actual process closely followed the construction of the original, but was made easier because of the sockets and wiring still remaining in the Beatbox case.  First of all, the end had to be sawn off the Stylophone circuit board, which is too long to fit in a Beatbox case; then the lowest 12 notes of the keyboard were connected to the 12 outside pads of the round Beatbox keyboard.  Fortunately, the wires attached to the Beatbox keyboard remained in the case, and just needed connecting to the appropriate Stylophone keys.  The Beatbox’s amp circuit board was taken out, but the Stylophone’s was kept and connected to the Beatbox’s speaker.  A power socket was connected to the Beatbox’s on/off switch, and the Stylophone’s on/off and vibrato switch circuit board disconnected.

I decided to replace the ‘Big Boy’s troublesome original 3-way octave switch with a simple  pitch potentiometer.  I used a 100k for  coarse tuning, in series with a 10k for fine tuning and a 100k variable preset to fix the highest pitch available.  Previous experimentation with Stylophones had taught me they have no objection to going down to very low pitches, but they cease to function – usually temporarily – if the pitch is taken up too high: on resetting, when this happens – by switching the power off and on – sometimes they will begin to work again, sometimes they won’t.

That’s what I did to the original ‘Big Boy’, and there’s no cure apart from throwing the circuit board away and starting again.  The likelihood of this happening is increased because I don’t just replace the tuning potentiometer pin-for-pin – the range of voltages available between the two pins the Stylophone uses isn’t wide enough for very large pitch variations, so I use only one of the pins that the original tuning potentiometer was connected to – the left-hand one – but connect the other one to +v.

The two new pitch controls were fixed to the front (the rounded end) of the Beatbox case, as was a replacement 10k log volume control.  The problem with the Stylophone’s original volume control was not that it wouldn’t work perfectly well, but that it would have had to be on the side of the case which I was intending to fix permanently to  the other Beatbox.

The original ‘Big Boy’ had no vibrato, but I decided the recreation should have a variable control, as fitted to the ‘Alien’, my first Stylophone modification project.  All this involved was connecting a 1M potentiometer instead of an on/of switch between the two vibrato connections next to the power connection on the main Stylophone circuit board.

Apart from an output socket and a switch to cut out the internal speaker, that half of the BigBoy BeatBox was done.

Stylophone half IMG_1132

2.  The Beatbox

The other half of the instrument was a plain Beatbox, with very little in the way of modifications.

(I don’t seem to have written specifically about the Beatbox in the blog, by the way.  Read the user guide here!)

The first thing I did to it was to replace the tuning potentiometer with a larger one of 100k (a direct pin-for-pin replacement this time), allowing for considerable slowing down and lowering of the pitch of the drums and other sounds.

I also followed an excellent example in this YouTube video: http://www.youtube.com/watch?v=xXdelnxXF7A to add buttons in parallel with the ‘Record’ and ‘Play’ pads normally operated by the stylus.  The trouble with the stylus-operated method is the delay in time between activating ‘Record’ with the stylus, and then using the same stylus to stop recording and begin playing the pattern you want to  be looped, as the loop begins the moment ‘Rec’ is selected.  With a small normally-open tactile switch as an alternative method of beginning and ending the recording period, you can be much more accurate as regards timing.

It’s worth mentioning at this point that, like the original Stylophone itself, the Beatbox comes in more than one variety, as far as circuitry is concerned.  I noticed two significant variations between the Beatbox I used in my ‘test to destruction’ phase, and the one that eventually found its way into the finished instrument: in one case, there was a tap from the battery compartment at 3v, which fed into the circuit (via the 3-way tone control) as well as the full 4.5v; and the layout of the circuit board was different.  As it happens, spots on the board marked ‘Rec’ and ‘Play’ were easily accessed in one case – the test unit – but not in the other – the one I was eventually to use.

In my experience, the Beatbox is a very delicate circuit, and it doesn’t take much to do something to it that will cause Record or Play to malfunction, or the output quality of the sound samples to degrade; so, proceed with caution, I’d say.

A third new button I added to this unit was ‘Reset’.  The Beatbox’s method of erasing an old loop and re-recording a new one is to switch the power off and on again.  The original power switch had to be removed as it was on the side of the case which was going to be fixed to the other Beatbox case – and there would, anyway, be a single power switch for both units: so the third button is a direct replacement for the Beatbox power switch, but now a normally-on, push-to-break, supplying power to the Beatbox side only.  To reset and re-record just takes a quick press and release of this button.

Finally, a new 10k log output volume pot was fixed to the front of the unit.

Beatbox controls IMG_1131

Beatbox halfIMG_1131

3  Joining the two halves

Superglue and two bolts was all that was required to physically join the two Beatbox cases, plus a couple of holes through which wires could pass from one side to the other.

The easiest way to connect the power seemed to be to detach the +v and 0v wires from the battery compartment on the Beatbox side and attach these to the original ‘Big Boy’ Stylophone side, which had a power input socket.

In the end I decided that whereas the battery compartment of the Big Boy Stylophone had to be removed – there was no room for batteries as well as the Stylophone circuitry – the one in the Beatbox could be used.  So I wired in a power cable which ran out of the back and was just long enough to reach the power socket in the other half.  In this way the instrument could be powered from an external source, or from internal batteries, and there was no need for a switch to change from one to the other.

The two 10k volume controls were taken to two individual tone controls.  I just wanted something fairly rudimentary, so I used a circuit from http://www.muzique.com/lab/swtc.htm called the ‘Stupidly Wonderful Tone Control’.  The component values I used were quite different – and I have no idea why – but the format of the circuit was more or less the same, and gave a little bit of variation to the tone.

After the tone controls, the two outputs were joined with 10k resistors to the original Beatbox volume control, and then the ‘Big Boy’ Stylophone amp circuit board.  This meant that the sound from both units was going to the ‘Big Boy’ half , and the volume and tone of each unit could be independently varied.  The input to the Beatbox amplifier was disconnected, and the speaker removed.

Now I had an instrument in a single conjoined case, with a single power supply and output through a single speaker or output socket.  There were two styluses and two keyboards, and – as I had hoped, but not expected with any confidence – both styluses work on both keyboards!  This means that both units can be played with a stylus in each hand, and quicker and more rhythmic patterns can be played.  I extended the wires to the styluses slightly to make sure they could reach right across both keyboards.

When using two styluses on the ‘Stylophone’ side of the unit, the ‘Beatbox’ side needs to be set to ‘Play’, otherwise that stylus will only work for a very short period and then not sound any more.  I haven’t timed the ‘very short period’, which might give a clue, but this is probably to do with the circuitry which regulates the maximum of 8 seconds (at ‘normal’ tempo) for which the Beatbox can record.

The complete circuit looks something like this:

BigBoy Beatbox circuit 2 Corrected sm

The following pictures show the inside of the instrument shortly before it was finished:

Inside Stylophone half with numbers 6 in IMG_1127

This is the ‘Big Boy’ stylophone half.

1 = speaker cutout switch

2 = socket for external 4.5v power source

3 = 3.5mm sound output socket

4 = Stylophone S1 circuit board with permanently soldered connections to first 12 keys

5 = socket for extra stylus, remaining from original ‘Big Boy’ design – not really needed now

6 = fine tune pitch control

7 = variable preset to prevent the Stylophone’s highest note from being too high and causing the circuit to malfunction

8 = coarse pitch control

9 = Stylophone volume control

Beatbox half with numbers 7 in IMG_1126

This the Beatbox half.

1 = the original Beatbox output and ‘mp3’ input sockets, no longer used

2 = Stylophone tone control

3 = Beatbox tone control

4 = Original Beatbox volume control, now master volume

5 = ‘Reset’, push to break switch

6 = wires going to ‘Play’ and ‘Record’ push to make switches mounted on top surface of Beatbox

7 = original Beatbox tempo switch, still in-circuit, but no longer used

8 = Beatbox pitch control

9 = Beatbox volume control

The features visible on the outside were these:

Front DSCF0003 3

Before finishing I gave the speaker grilles a coat of blackboard paint.  The reason I used blackboard paint was a) it was the only black paint I found in my garage not in a spray can, and 2) it gives a pleasing matt finish, but is more durable than water-based matt emulsion.

The rear of the instrument was sprayed black and the holes masked with painted material.

New Back IMG_1130Front & Rear View IMG_1129_30

22
Aug
12

Stylophones 3 – The Stylophone 350S, Part 1

A series on the Stylophone can only reach a climax with the mighty 350S!

The question of why the original Stylophone sold in its millions and became a world-wide success story, and the 350S didn’t, has long been debated.

According to http://stylophonica.com (‘The official home of the Stylophone’), it was ‘too costly, and lost the key uniqueness of the Stylophone itself, which was its small size and mass-market appeal’ – but it certainly wasn’t through of a lack of features.

You may be familiar with the Stylophone, but not the 350S: if so, then to start with, a run-down of its capabilities is required:

First of all, it’s certainly true to say that it’s much larger than the regular Stylophone – which is, after all, about the size of an inch-and-a-half thick postcard.  Here’s my 350S together with the regular-sized ‘New Sound’ Stylophone with which it shares many of its design cues:

350s + New Sound IMG_1050

The 350S is a souped-up Stylophone in every way: instead of the Stylophone’s 20 notes – an octave and a half – the 350S has 44.  That’s three and a half octaves, and you can see in the picture the difference in length between the two keyboards.

Not only that, the 350S has eight voices, as opposed to one (or even the S1’s three), and some of these are themselves in different octaves.

The voices are designated ‘woodwind’, ‘brass’ and ‘strings’.  In these days of sample-based synths, none of these sound terribly much like what they say they are, but they have the general qualities of these instruments – and, despite what you may read, one or two of them are quite like the distinctive tone of the regular Stylophone that we all know and love!

These voices are:

four ‘Woodwind’ voices pitched at four different octaves, and described (like organ stops) as 16′, 8′, 4′ and 2′;

two ‘Brass’ voices at 16′ and 8′; and

two ‘Strings’ voices at 4′ and 2′.

Because these voices are pitched at different octaves, from 2′ to 16′, in all no less than six and half octaves are available from the bottom of the keyboard to the top.  This is almost as large as a ‘professional’ 88-note synthesizer keyboard.  Up to two of the voices can be combined at any time, one each of the four octaves.

As well as this wide range of voices, the 350S has a variety of built-in effects.  Like the regular Stylophone, one of these is Vibrato – and two speeds are available, rather than one.

There is also a two-speed ‘Decay’ facility: as well as the usual Stylophone ability to hold a note as long as the stylus is in contact with the keyboard, when the Long or Short (actually, ‘short’ or ‘very short’) Decay button is pressed, the note will fade out while the stylus is still in contact.  According to the nicely-produced, LP-sized User’s Guide that comes with it, this enables the player to obtain ‘a percussive effect rather like  piano.’

350s rocker switches IMG_1053 sm

However, as can be seen from the above picture, this is only the beginning of the 350S’s abilities.

The fast or slow ‘Reiteration’ button (second from the left) can be used to imitate the sound of a banjo or mandolin, and the 350S even has a second stylus which is used to produce these effects.

Normally, whichever stylus is being used, the ‘regular’ or ‘reiteration’, it’s held in the right hand; but it’s possible to play two notes at once in reiteration mode by using the reiteration stylus with the right hand, and playing lower notes with the regular stylus in the left hand.  It doesn’t work the other way round, and it doesn’t work in ‘normal’ mode, i.e. without either the fast or slow reiteration switch pressed.

The white tuning control can also be seen in the above picture – handily placed on the front of the instrument, unlike its counterpart in the regular Stylophone, which is always hidden underneath.

The most unusual effect, though, has got to be this:

350s Photo control IMG_1052

Above the volume control is the 350S’s secret weapon – the ‘Photo Control’.  This device, operated with the player’s left hand while the stylus is wielded in the right, can be set to control the volume, amount of vibrato or low-pass filter cut-off point – acting as a ‘waa waa’.

On the side of the 350S, next to the Photo Control, are three 1/4″ mono jack sockets.:

350s sockets IMG_1051

While one of these is ‘sound in’ and another ‘sound out’, the middle one is a socket for a foot pedal that replaces the Photo Control – either because the player would prefer to control volume, vibrato or waa with their foot, or because the ambient light level is too low for the Photo Control to be effective.  A 50k – 100k potentiometer does the job, according to the User Guide.

My experience of light-dependent controls like this – and I’ve made a number of them – is that they are really only fully effective when quite a bright light is shining on them, which is not always the situation when you sit down to play.

Unsurprisingly, this magnificent machine requires a fair amount of juice, so it’s powered by not one, but two weighty PP9 batteries, connected in series to provide 18v of power to the 350S.  [Edit: but see notes below about powering the 350S].  The batteries are housed underneath the rear of the instrument:

350s back IMG_1056

The battery covers look as if they’re held in place by screws, but these aren’t really screws: they click into place when pushed, and just require a slight turn with a screwdriver or a thin object to loosen them.  (The User Guide suggests a coin, but in my experience modern coins are too thick to perform this function.  Maybe a 5p would do it).

This is the User Guide that came with the 350S:

p1

350sBooklet

Reliable information on when the 350S first came on the market, how many were sold, etc. seems hard to come by.  http://stylophonica.com says: ‘No more than a few thousand 350S’s were ever sold’; http://stylophone350s.com/ says ‘Dubreq, the manufacturer of the original Stylophone created and produced the Stylophone 350S beginning in 1971 . . . fewer than 3000 were ever produced’ and quotes a Ben Jarvis (son of Stylophone inventor Brian Jarvis and re-founder of Dübreq in 2003) estimate that only 200-300 working units are probably still available worldwide.

I’d be surprised if the numbers were quite this low, but they’re certainly not common, and those that appear on eBay in the UK frequently command in excess of £100, rarely less than £70. Stylophone350S.com in the States have access to a recently discovered cache of mint condition boxed examples, which are now on sale.  Their website tells the story of this amazing find.  [Edit: this site is now defunct, unfortunately.  I don’t know what happened to the mint condition 350S’s that were for sale there].

The back of the 350S is removed by undoing 4 large screws in the corners and two very small screws under the front, and reveals two printed circuit boards: a thin, narrow one at the front containing the keyboard and the resistor chain – not discrete resistors, but what I’ve previously called ‘resistor modules’, since I can’t remember what the proper name for them is – and a large, rectangular one with everything else on it, including potentiometers, sockets and switches:

Just opened IMG_1068

The circuit boards themselves come away quite easily: there are 4 screws, clearly visible in the above photograph, which hold the keyboard in place, and 6 similar ones for the larger board.  The volume control knob doesn’t need to be taken off – it fits through the hole surrounding it – but the plastic nuts on the three sockets need to be removed.

This is what the other sides of the boards look like:

Component side IMG_1070

Here we see the larger items across the middle of the board, from left to right: the three sockets, the volume control, the eight voice and effect switches, the pitch control and the on/off switch.  If I was an electronics expert, I could tell you what the rest of the components do; but I can’t.  I can only surmise that the round inductor next to the left-hand switch is to do with the waa circuit; the LDR (light-dependent resistor) to the left of that is the ‘Photo Control’.

LDR & Ind New IMG_1144

The black ‘hood’ that partly surrounds the LDR was slightly damaged when I came to look at it, and it’s quite possible that I did this myself when I opened the case.  It was easily repairable with a spot of superglue, but watch out for this if you’re looking inside yours.

The ferrite core inductor is a Mullard FX2236.  In this close-up you can see that mine looks a bit broken.  I don’t know enough about these things to know if this means it isn’t working properly, but, while by no means common, they can be found – perhaps more easily in the UK than elsewhere – so I shall certainly consider replacing it.

According to the experts at www.stylophone.com, under the heading ‘VITAL INFORMATION WHEN BUYING A 350S… PLEASE READ CAREFULLY!’, one of the components you can see here – which they describe as the ‘Amp-ic’ – is highly prone to failure.

The related website, the Stylophone Information Centre at www.stylophone.fsnet.co.uk says: ‘The circuit board carries an IC which controls sound output, and this component (long since obsolete) is the single- most likely cause of the 350S to break down. If this happens . . . the unit will only be heard if played through a separate amplifier, if at all.’

The symptoms to look out for are: ‘when the stylus is applied to the keyboard, only a very faint sound is heard (if even audible at all), which fades away rapidly . . . Even with the volume control turned up to max, the sound will still be very low – then quickly fall away. The user will then be left with a ‘dead’ 350S.’

The chip in question is this one – the black one with six legs in the middle of the picture:

MFC6070 New IMG_1145

It’s a Motorola MFC 6070, 1-watt power amplifier  – ‘designed primarily for low-cost audio amplifiers in phonograph, TV and radio applications’, according to the datasheet.

If you don’t know what a phonograph is, ask your grandad, he’ll remember them!  The use of this antiquated vocabulary confirms what is said above.  If you find the datasheet for this chip, it says ‘Device discontinued – consult factory’; if you try to buy one on the Net, you’ll mostly find specialist sites, dedicated to sourcing obsolete parts.

As a matter of fact, you can, at the time of writing, get one on eBay for about £20, but you aren’t going to want to do that: the problem doesn’t arise, apparently, just because 350S’s are now all old – it even used to happen to quite new ones.

Stylophone.com told me that ‘the original chips as fitted . . . were working very close to their breakdown point voltage-wise. Although theoretically all the chips supplied to them should have worked, Dübreq actually had to batch-test the chips to find those with an acceptable working voltage range, especially the maximum voltage’ (which is meant to be 20v). ‘We’ve seen some of these chips.’ they said, ‘ running extremely hot (basically too hot to touch) by simply switching the instrument on, before even playing a note.’

That’s not to say the MFC6070 was a particularly unusual part at the time – they were used all over the place, and even the venerable VCS3 synthesiser used one as a driver for its spring reverb circuit.  However, as the site offering VCS3 spares, http://www.synthi.com, says: ‘The Achilles heel of the VCS3/Synthi AKS are the now obsolete and ultra rare semiconductors that it uses’ . . .

This made me think twice about powering the 350S with a mains-powered adapter: the increased risk of overdoing the voltage and blowing the chip might not be worth it.  Dübreq themselves did apparently produce some 350S’s with an ‘adaptor socket factory-fitted’, but ‘this led to many of them blowing the chip.’

I’m not quite as worried as I was, however, as stylophone.com are now marketing a new module, the ‘Stylophone ACM’, which can be retro-fitted to an ailing 350S – or even to a working one, as a precautionary measure – to get round this problem altogether.

The circuitry inside this unit is not operating close to its limits, and makes it much safer to run the 350S from an 18v adapter.  (And if you buy a reconditioned 350S from stylophone.com, it will already have one of these in it).

[Edit: see comments from Christian Oliver Windler below relating to powering the 350S.  He concludes from his tests that the 350S could – and should – be powered at less than 18v, and preferably less than 15v.  Some of the above problems and their expensive solutions can thus be avoided.

As with the original Stylophone, by the way, there appear to have been various upgrades during the course of production, and it’s interesting to note that some of the components inside Christian’s 350S differ from those in mine].

As a matter of fact, this is not the only ‘obsolete’ component in the 350S.  Although the resistors, capacitors and transistors that fill the circuit board are not commonly used in new designs nowadays, they’re still readily obtainable; the round silver integrated circuit over on the right-hand side, just above the tuning control, isn’t.

AY15051 New IMG_1142

It’s a General Instruments AY-1-5051, and what it does is frequency division (presumably for the 350S’s different octaves) – the kind of thing modern CMOS 4000-series chips do with the greatest of ease.  There’s a description on this website: http://www.divdev.fsnet.co.uk/repair2a.htm of how one might make such a replacement (using the example of a 1960s Elka electronic organ).  All I can say it, it looks feasible in theory, but not something I’d want  to be faced with in practice – let’s hope this isn’t a part which is going to fail!

Returning to my 350s, it looked badly in need of a clean up.  There was a lot of dust inside it, and over the years the keyboard had got very dirty:

Corroded keyboard IMG_1072Dust and corrosion IMG_1076

The switches sounded OK – no crackling or intermittent operation, so I left those, and just cleaned the circuit board and keyboard.  The keyboard in particular needed attention from, in order, a soft brush, switch cleaner, WD40 and Brasso.   This seemed to do the trick, and it began to look shiny again.

I cleaned everything, including the switch rockers, the case and the tips of the styluses, and put it back together again.  It now looked much better, and sounded clearly and reliably on every note.

Outside after cleaning IMG_1091

In my next post in this series, I’ll take a longer look under the bonnet of the 350S and see what there is to see.

21
Jul
12

Stylophones 2 – Variations

As I said in my first post on the Stylophone, there have been a number of variations in Stylophone design over the years, so I thought I would illustrate some of these from the examples in my collection.

The earliest Stylophone – in the days before Rolf Harris adorned the box – looked like this:

Original Stylophone + box IMG_1035

This early variation is distinguished by the non-playable black sections of the keyboard.  There were three types, distinguishable only by the body colour – the black one illustrated was the ‘standard’, but there was also a white one, the ‘treble’, and also a ‘bass’.  I don’t know what colour it was: I’ve only ever seen it in pictures, and it looks like a reddish-brown to me, but I’m colour-blind, so an unreliable witness . . . I hope in time to get hold of one, and somebody will tell me if it is indeed brown!

Here is the booklet that you see pictured above:

p1

Read the Original Booklet.

The black sections of the original keyboard had been a feature of Brian Jarvis’s prototype – which you can read about here: http://www.stylophone.com/Prototype.html – but the next generation of Stylophones dispensed with them.

There were still three types – the black ‘standard’, the white ‘treble’ and the (presumed) brown ‘bass’, and they looked like this:

2nd generation IMG_1057

Note the identical case design to the original, but the keyboard is now completely silver.  (Ignore the switches on the sides of these instruments – they’re a speaker cut-out modification I made to them many years ago).

The circuits in all these early Stylophones were quite similar, although not identical.  The instrument was subject to constant development, and there are versions with all discrete components, including the resistors which determine the pitch of the notes, and versions with different types of resistor modules – rows of resistors in a single unit.

It’s easy to peer into the inside of the original and ‘2nd generation’ Stylophones: the back is designed to be easily removable, in order to change the battery, and the component side of the circuit board is visible.  This is the inside of an original version (the one with the black sections on the keyboard):

Original inside IMG_1060

As you can see, in the middle, just above the piece of foam rubber which keeps the battery in place, there is a row of resistors connected to the keyboard, which determine the pitch.  This arrangement continued with the 2nd generation Stylophones.  This is a view inside the black ‘standard’ version pictured above:

2nd gen black inside IMG_1058

(Ignore the large resistor at the back right-hand side – this is attached to the speaker cut-out mod).

At some time during the production of the 2nd generation Stylophone, resistor ‘modules’ came into use.  This picture of the white version pictured above, shows two orange-coloured blocks in place of the row of separate resistors:

2nd gen white inside IMG_1059

Other slight changes were made to the component layout, and the style of the switches in the bottom right-hand corner is different.  (Once again, ignore the non-original large resistor next to the speaker).

This would be a typical version of the circuit from this period:

Stylophone schematic 2

A slightly different one is illustrated here:

http://www.waitingforfriday.com/index.php/Reverse_Engineering_the_Stylophone.

Also at some point during production of the 2nd Generation Stylophone, there was a major change on the outside.  The shape and colours didn’t alter, but the guide to the notes, printed on the white background piece stuck around the keyboard and switches changed from showing notes (‘A’, ‘A#/Bb’, ‘B’, etc.) to numbers (‘1’, ‘1 1/2’, ‘2’, etc.):

Letters & Numbers IMG_1057

(These are the same two black and white Stylophones shown above).

This was the beginning of the famous Stylophone song-teaching method, which continues until this day.  Whereas the songs you learned from the original booklet were shown with notes, like this:

Original Booklet p7

songs were now shown with numbers, like this:

p8

Edit: However, there is a photograph of an object from the collection of the Museum of Design in Plastic at http://www.modip.ac.uk/artefact/aibdc–002025 which shows an original issue Stylophone (the one with the black sections on the keyboard) in its packaging: and one of the items included is an overlay for the keyboard surround.  First of all, this is white lettering on a black background, rather than black lettering on a white background; secondly, it uses numbers, not letters for the notes.

*

The third distinctly different type of early Stylophone was the ‘New Sound’, which came out in around 1975.  The sound was ‘new’ because instead of the transistor in the original, the oscillator used a 555 integrated circuit.  Mine came in a box featuring Rolf Harris:

New Sound in box IMG_1048

This Stylophone featured, for the first time,a volume control, which can be seen on the left of the front panel, just above the on/off and vibrato switches.

The circuit for the ‘New Sound’ version looked like this:

555-based Stylophone circuit.LARGE

This view of the inside of the ‘New Sound’ shows the black, rectangular 555 chip just above the centre of the circuit board:

New sound inside IMG_1061

The Booklet that came with the ‘New Sound’ Stylophone was more extravagant than the original – although it was only printed in black and white, it was 16 pages long and the pages were about twice the size:

p1

Read the New Sound Booklet.

*

Edit: Not part of my collection, but of interest nonetheless, is a variation made in Hong Kong and sold mostly in the United States.  These are described in detail at http://www.stylophone.ws/hk.html, but a correspondent, ageing60hippy,  has sent me some very nice photos of one that he has.

It can’t be stated for certain if these stylophones were copies as a number were manufactured under licence at this time, but they have several features which differ significantly from the versions being made in the UK.  Note the ® symbol after the Stylophone logo on the front grille, the socket for an external 9v power supply, and the small battery compartment on the back.

Imgp3462Imgp3436Imgp3443Imgp3449

Inside, the circuit board design is different and the construction quality perhaps not quite the equal of the originals, but not bad for this period:

Imgp3458Imgp3450

*

All of these early series of Stylophones offer opportunities for modification and circuit-bending: the electronics aren’t complex, circuit diagrams are often available, and the components themselves are large and readily accessible.

I haven’t worked on these much, but my SoftPot Stylophone is a modified ‘2nd Generation’ treble version.  The ‘Hedgehog’ uses a Stylophone ‘New Sound’.

Production of the original Stylophones ceased in 1980 and the manufacturer, Dübreq, moved on to other things (‘Top Trumps’ playing cards!), but in 2006 the design was revived.

The new ‘Stylophone S1’ had different electronics inside, but a more or less identical case design.  Only by looking carefully can you see the tell-tale signs: the extra socket on the side – an ‘mp3’ input – a volume control on the right-hand side, and a three-way tone switch on the front, none of which is present on any of the 1960s and 1970s Stylophones:

Stylophone S1 2

Several colour variations – sometimes referred to as ‘Special editions’ were produced.  These were all-black (‘ebony’), silver and white:

4 S1s IMG_1044

Unlike the earlier Stylophones, the colour isn’t an indication of different sounds – as all S1’s have 3 tones, there was no longer any need to make three different types.  They’re all identical on the inside – although I did have the impression that a little more care was given to the assembly of the Special editions, compared to the standard version.

*

In Asia an even more completely black version, the ‘Stylophone Studio’ was marketed:

StylophoneSBE_package_Full lge

They’re very uncommon in Europe and I’ve never seen one.

[Edit: I’ve finally acquired one!  Here are some pictures:

IMG_0607aIMG_0612IMG_0613

As you can see, it’s VERY black!  I like the contrasting white switches].

*

This is the booklet that came with the Stylophone S1:

p1

Read the S1 Booklet.

The version that comes with the black ‘Stylophone Studio’ is mostly in Japanese (at least mine is, having been purchased from there; different languages may have been used if it was sold in other countries):

IMG_0609_10IMG_0611_12

*

Another rare variation of the S1 is the so-called ‘Raconteurs Tour edition’ – a special version made to be sold as part of the merchandising connected with The Raconteurs,  a band formed by Jack White after the dissolution of the White Stripes.

Both the colour scheme of the instrument and the package design were unique, with a distinctive black and gold colouring:

Raconteur + box IMG_1036

In addition, the contents of the booklet were customised for the band:

p1

Read the Raconteurs Booklet.

According to a concert-goer (at http://cousinsvinyl.com/2008/dude-check-out-the-merch-raconteurs-and-black-lips-play-the-fillmore-detroit/): ‘I was very curious to see what a Stylophone was.  The box read “The Original Pocket Electronic Organ”.  My friend said, “Dude, you’re going to want to get one of these,” as he opened the box.  It was $40, but worth the money: it’s a working instrument with the Raconteurs logo on it.  The next day, it was worth $200 online.’  Mine was a lucky find on eBay, but these can be very expensive when you come across them, usually more than the original $40 price tag.

[Edit: True at the time of writing, but less so now!]

As an added attraction for those who bought the Stylophone at Raconteurs’ gigs, the band held a competition, inviting fans to submit Stylophone versions of their songs.  The competition was announced on the band’s website:

Raconteurs competition

 The video made by the winner, Zach Herrmann, can be seen on YouTube at http://www.youtube.com/watch?v=2eK17MqWIo0. [link now dead]

The circuitry of the S1 is very different from the earlier Stylophones, being based on a tiny digital chip which you can’t even see as it’s covered in a blob of protective wax.  It has a separate amplifier circuit board.  It also runs on 4.5v, not 9v, so instead of a PP3 battery it takes three AA batteries.  These are not inserted by removing the back of the instrument like the earlier ones, but are held in a battery compartment accessed from outside.  For this reason, the S1 is glued shut and getting to the inside of it for the purpose of modification (or troubleshooting) is not a simple matter.

The only picture of the inside of an S1 I seem to have to hand is this one, which has points marked on it for a ‘feedback’ bend: but it clearly shows the components which are visible on the main circuit board – i.e. not very many! – and the amp board in the background:

Inside stylophone sm

The chip which does all the work is under the black blob; the resistors are tiny surface-mounted (SMD) type.

For this reason, modifications and circuit-bending opportunities are a little more limited than with the early series of Stylophones.  Elsewhere in the blog are one or two examples of my efforts: The ‘Alien’ was my first modification project; the ‘Gemini’ uses two S1 boards in a single case.

And finally, a word about the smallest ever Stylophone, the Stylophone mini:

stylophone-mini

This one really is miniature!  Measuring a mere 8cm x 4.5cm, this is an official Dübreq/re:creation product, and is a perfect reproduction of the regular Stylophone.  Powered by 3 AAA batteries, it has a working stylus and the full complement of 20 notes.  The only thing it lacks is the Stylophone’s traditional Vibrato.

Here is a Stylophone mini with a regular Stylophone S1:

Mini Stylophone IMG_1042

Inside, there seems to be very little indeed!:

Stylophone mini IMG_1094

It looks as though the keyboard is connected to a small piezo element acting a sounder, with very little in between!  I didn’t take the circuit board out on this occasion to look, but I suspect, like the S1, the chip which operates the Stylophone mini is very small and surface-mounted on the other side.  It certainly looks as though modification and bending possibilities are limited.

That’s an overview of the mini and regular Stylophones; my next post on the topic will deal with the amazing machine often described as the Stylophone’s ‘big brother’, the 44-note, 8-voice Stylophone 350S:

Outside angle after cleaning IMG_1089




andymurkin

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