This is my live guitar effects right as of Feb 14, 2009. Please let me know if you find it useful or have any ideas for effects or other improvements. If you make some music with it, I'd love to hear it!
Once I have some more time to program it, my next effect will probably be a Vocoder.
Run effectsrig.pd to load it up. A midi expression pedal is recommended for the best experience - but it's not required.
It contains the following effects:
Digitech whammy style pitch shifter. Allows for smooth changes to the pitch shift amount.
Based on the one posted by "kenn" on the puredata.info forums (which in turn is based on the pd example code).
A "shimmer" synth-like effect. This is done with a pitch shift in a feedback loop of a very short delay.
Octave-up distortion like you can obtained with the classic transform and 2 diodde rectifier circuit. Basically it just full-wave rectifies the audio signal. This one really brings out the high frequencies (some times a little too much!).
A stereo leslie (rotating speaker) simulator. This is one of my favorites. If modulation is turned all the way down it becomes tremolo. Take one of the outlets for mono use. Try it in stereo for super-swirley bliss! When using an expression pedal to control the rate, heel down will bypass the effect.
Expression pedal control is done by expression.pd. It simply reads in MIDI and scales it to a 0->1 range. You can change the midi channel used by editing this file.
The preset system is a little hack-ish, but it works for me. If anyone has any better ideas on how to do this, I'd love to hear them. When you load up the main effectsrig.pd file, you will see a bunch of message boxes. This are quick settings buttons - just click one to apply that effect. They are designed so you can click a couple in a row to quickly apply a few different settings. To start over, click the big "default" one on the left.
It can also load presets based on midi messages. I use this with my Eventide TimeFactor pedal. When I change presets on the TimeFactor, PD follows along. This is handled by the box in the top right. The symbol box is for song titles, and the number boxes show the current TimeFactor preset. Open this box to see how I've done a couple of example midi controlled presets. "pd your_love_never_fails" is a more complicated example that changes the expression pedal behavior slightly.
If you want to use a different midi channel for listening to program changes, just edit preset.pd and presetnum.pd. preset.pd outputs a bang when the preset number supplied as a parameter is chose. presetnum.pd just outputs the number of the selected preset.