Sounds of Nature with the SoundSpa

After finishing the Black Widow, Mk II, I had some fun using natural sounds with it – rain, birds singing, that kind of thing.  The final feature I had added to it was the ability for it to play automatically, which, though not quite as good as manipulating the samples with the Flight Controller throttle and joystick, would allow the Black Widow to keep operating, leaving the hands free to play other instruments at the same time.

While I was thinking about natural sounds, I came across an interesting-looking device called the SoundSpa, which is designed to soothe you to sleep with sounds of nature, including rainforest, ocean, rain, waterfall and ‘summer night’.  This sounded like a good candidate for some circuit-bending!

These machines do appear on eBay from time to time, and I was very fortunate to get one there for three or four pounds, including a handy mains adapter.  I hadn’t really done any circuit-bending, except for my work with Stylophones – like the Alien and the Hedgehog – but I described that as modification, in the sense that I knew what kind of circuit I was dealing with, and I knew more or less what I wanted to do with it.  The art of circuit-bending is, by tradition and by its very nature, more experimental.

As it happened, just at this moment, I came across an ad for a circuit-bending workshop, which I decided to attend.  So the story of the creation of the BentSoundSpa is also the story of my day at the wonderful Music Hackspace in Cremer Street, London.

The workshop was organised by Susanna Garcia and run by Tasos Stamou.  Tasos has created some great music, partly using circuit-bent instruments; you can read about him and hear some examples of his music on his website: http://www.tasosstamou.com and some examples of the circuit-bent instruments he uses here: http://stamouinstruments.blogspot.co.uk.

There were about a dozen of us taking part, and enough musical toys to go round.  I took the SoundSpa along and worked on that.  First we were encouraged to start our devices playing, take leads with crocodile clips and find connections which produced effects that were, well, interesting, unexpected, dramatic . . . all of which we did. There were glitches, repeats, jumps and crashes  - but the devices seemed surprisingly resilient: when they crashed, it was just a matter of taking a battery out for a moment, putting it back, and everything would be working again.

The workshop was designed to be suitable for complete newcomers – which several of us were – so we were deliberately encouraged not to speculate on what the parts of the circuits were for, and proceed by exploration.

Nothing very exciting was produced by the SoundSpa until we looked specifically at making pitch changes, dabbing at resistors with a damp finger.  Having found the right one, we cut it from the board and replaced it with a potentiometer.  A range of values was provided, so we could pick the most suitable, and soldering irons were available to replace the crocodile clips when we were happy with our choices.

I found a very high value, 2.2M, which took the pitch of the sounds right down to almost standstill.  The only problem with taking the pitch up high was – just as I had experienced with the Stylophones – the resistance was so low the device crashed, so a small resistor was needed to stop this happening.  I calculated this would be around 10k.  On the day, I found a value high enough to prevent crashing, and when I got home I replaced this with a 10k preset, setting it just high enough to keep the device running when the potentiometer was at maximum.

After this picture was taken I decided to add a second, smaller potentiometer – 100k – in series with the large one as a kind of ‘fine-tune’ control.  This has a much larger effect at higher pitches when the resistance is low on the bigger one.

Then, to finish, we went down to the workshop, drilled holes for the potentiometers and added a 3.5mm output socket which would cut out the speaker when plugged in.

I considered replacing the original on-off switch/volume control since it was a bit dodgy – as was the one on Tasos’s example, one of several of his instruments which he brought in to show us – but it works OK with a little persuasion.

Obviously, the effects available from it depend on the wide pitch and speed variations available.  Like the Black Widow, the addition of a variable filter such as the StyloSim or the Active Low-pass Filter would add to its versatility.  I haven’t used it properly yet, but I’ll post a sound file as soon as I have one.

The Touch-Radio

The Touch-Radio was, design-wise, by far my easiest project to date.  This was for the simple reason that it’s essentially the circuit board out of an old transistor radio, more or less unaltered!

I had had the radio for about 40 years: about 20 years ago, I took it out of its case – which has subsequently disappeared – and rewired the tuning and volume controls, evidently intending to do something with it.

I forget now whether I ever did – probably not – but I found it again recently, just as I was finishing the Cracklephone, and thinking about touch-controlled sound-makers; so I decided to connect a battery clip and speaker and see if it made a noise.

It did!  And I soon discovered that by touching certain parts of the exposed circuit board interesting sounds could be coaxed out of it – often not entirely unlike the Cracklephone, but with an element of speech incorporated.  Touching the aerial did frequently amplify the received radio signal, but it was rare for speech to become readily intelligible.

So I decided to leave it at that! – apart from putting the speaker, volume control and power in a box, to keep it neat.  A PP3 battery would just about fit inside, but it also has a socket for  external power.

I’d recently obtained some small plastic jewellery boxes, which looked good for small projects (some more are described elsewhere in the blog), so I used one of these.  There was also room for two 3.5mm sockets and two 4mm banana sockets, which I added, as I had done for the Cracklephone, to allow a microphone to be attached to the Touch-Radio or the Touch-Radio to be connected to an external loudspeaker.

I’ve always been interested in manipulating speech sounds, and have a number of projects in mind utilising radios in different ways.  I haven’t started working on these yet, but the Touch-Radio is the first in the series.

Circuit-Bending

Circuit bending is rather nicely described in the Wikipedia (at http://en.wikipedia.org/wiki/Circuit_bending) as the ‘creative customization’ of electronic devices such as ‘low voltage, battery-powered guitar effects, children’s toys and small digital synthesizers to create new musical or visual instruments and sound generators’.

The true method of approaching circuit-bending (IMHO, as they say) is experimental, without having – or without deliberately using – knowledge of the circuit you’re working on; the enjoyment of chance discovery is an important element of the experience, which is why I have distinguished it in my projects from ‘modification’, where I felt a knowledge of electronics and the circuitry being worked on was a useful thing.

The guru of circuit-bending is Qubais Reed Ghazala (http://en.wikipedia.org/wiki/Reed_Ghazala), and his book Circuit-Bending : Build Your Own Alien Instruments (pub. Wiley, 2005, ISBN 978-0764588877) is the standard work on the subject.  It explains how he came to discover the idea of ‘bending’ – leaving a small, battery-powered amplifier in a desk drawer, the power on and the back off, where a metal object in the drawer touched parts of the circuit and produced marvellous noises – illustrates some of the instruments he has created over the years, and gives detailed instructions on how to ‘bend’ some popular electronic instruments and toys available today.

If you’re not able to obtain a copy of Reed Ghazala’s book, you can read about it on his website at www.anti-theory.com, and follow a step-by-step tutorial at www.anti-theory.com/soundart/circuitbend/cb01.html.

A fabulous website for electronic music fans is www.electro-music.com; in this case a browse through their Circuit-bending forum at http://electro-music.com/forum/forum-113.html will throw up heaps of advice on what devices to get and what do with them once you’ve got them.  This may at the outset involve only making sure it’s using batteries, not plugged into the mains, switching it on, wetting your finger and poking the circuit board until something interesting happens.

So, if you’d like to get into electronic music, but are put off because you know nothing about electronics, then circuit-bending may be the thing for you, as Ghazala emphasises the fact that no knowledge is required!  Right at the beginning of Chapter 1 of his book he tells the story of taking his first circuit-bent instrument to school, ‘synthesizing birds, helicopters, and police sirens on the instrument, and running electricity through several people at a time so that we could play the device by touching each others’ bare flesh.’  His teacher is very impressed, looking at the dials and switches and hearing the extraordinary sounds.  ‘Mr Ghazala,’ he says, ‘I didn’t know you knew anything about electronics.’ ‘I leaned forward’, Ghazala tells us, ‘looked him straight in the eye, and said, ‘I don’t.’

At the time of writing I haven’t begun any of my planned projects in circuit-bending, but I’ve been collecting some suitable devices to work on.  I’ll report on these as soon as I’ve been able to get started; in the meantime, here are some of the items I’ve acquired.  I’m particularly interested in the human voice in this context, so you will see a Texas Instruments ‘Speak and Spell’ amongst them, a Vtech ‘Alphabet Apple’ and a Casio SK-60, famous for its ‘human voice’ presets.