Interesting thought. I don't know anything about PID controllers - are they so compute intensive that they need a processor significantly more expensive than a

Interesting thought. I don't know anything about PID controllers - are they so compute intensive that they need a processor significantly more expensive than a Bluetooth controller? On the guitar effects pedal: Apple has actually run an iPad ad that included a shot of a guitar plugged into an iPad running an "amplifier emulator" (not sure what the right term is for that sort of thing). Not sure which app it is, but it's probably $10 or less. :)