Archive for September, 2015

26
Sep
15

Guitar FXBOX – Part 3, developments

After finishing the FXBOX foot controller, I started to use the FXBOX and soon decided on a few changes to the software.  There are now 3 areas in which there are differences from the original description of the software in Part 1 of this series of articles.

1  I had been using external pedals to add and change pitches, so I decided not to implement the ‘Pitch’ function.  I’ve left a reference to it on the main FXBOX screen, as it’s still for the time being referred to on the foot controller – and I may decide to bring it back in future.

ishot-1*

2  The next change can be seen in the bottom right-hand corner of the main screen.  In order to enhance the shimmering effect of the spectral delay and the freeze I added a simple looper.  This would enable the delay and freeze effects to be repeated continuously, providing a background for melody or other sounds.

ishot-5I added a half-speed and double-speed playback facility, to allow for some variation in the sound produced.  The double-speed is particularly effective for higher-pitched ‘tinkling’ sounds.

Section 11 of the foot controller, which wasn’t being effectively used, was altered to allow for hands-off control of the various loop functions.

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3  I added MIDI control for changing the variable parameters – volume, mix, chorus rate, depth, and so on.

I have a set of the original Korg ‘Nano’ controllers, NanoKeys, NanoPad and NanoKontrol, so I used the NanoKontrol for this application.  (This is a great device – very useful and usually quite cheap on eBay.  Versions 1 and 2 seem quite different in various respects, but I don’t think it would matter which you used for this application.  Version 2 doesn’t have the ‘scenes’ concept, but something else instead, I believe).

First of all I used Pure Data’s [ctlin] object to separate the incoming MIDI Channel, Continuous Control (CC) Number and Value information:

ishot-7then sent that information to control the values which would normally be set when the program opened, and altered by hand on the main screen –  a fiddly operation, on  top of having to stop playing in order to do it.

Here are a couple of examples of how it was done.  The calculations after the receipt of ‘midivalue’ are to translate the MIDI scale of 0-127 to the scale of the parameter being changed, which might be 0-1, 1-100, 1-128  or anything else.  The [loadbang] instruction ensures that, in this case, envelope sensitivity is only affected when CC Number 14 is received, and envelope attack is only affected when CC Number 15 is received.

ishot-9

As well as the CC Numbers having to be carefully specified, it was also important to ensure that the FXBOX responded only to messages on its own MIDI channel.  I used Scene 1 on the NanoKontrol; I can’t remember if MIDI Channel 11 was the default, or if I changed it to that using the Korg Editor:

ishot-10

In any event, it was set to Channel 11, and I amended the Setup screen so that the MIDI Channel received by the FXBOX could be changed:

ishot-3The revised files required to operate the FXBOX (the foot controller and MIDI control are entirely optional) are here:

http://www.andymurkin.net/Electronica/FXBOX/abswitch~.pd

http://www.andymurkin.net/Electronica/FXBOX/crossfader~.pd

http://www.andymurkin.net/Electronica/FXBOX/expression.pd

http://www.andymurkin.net/Electronica/FXBOX/FXBOX22.pd

http://www.andymurkin.net/Electronica/FXBOX/Guitar_specdelay~.pd

http://www.andymurkin.net/Electronica/FXBOX/LoopGenerator.pd

http://www.andymurkin.net/Electronica/FXBOX/midiin.pd

IMG_0399IMG_0400

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This edited improvisation gives an idea of the sounds the FXBOX makes:

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