Category Archives: Pedals

Behringer FX600

Reader asked a question and its been a while since I thought about circuit bending guitar pedals, but here is some general knowledge that may be useful for someone to take the mystery out of this process.

“Usually most modern pedals are completely digital with 1 or 2 chips making the whole thing go. So if you start poking around you will simply crash it because you interrupt the CPU frequency crystal timing. Not much there except maybe adding the LTC Precision oscillator to pitch the whole thing up and down.

There are OP amps here and there to amplify the signal and that will give you some feedback bends.

The glitchy bends in digital equipment come from messing with the ROM chips where waveforms are stored or RAM chips where the input audio gets held up for delay effects and loops etc. However in modern electronics those are extremely small and hard to work with.

A reasonable way to get  interesting sounds out of modern guitar pedals is to have a signal feedback mixer and also explore adding some LFO variations to the knob parameters or CV inputs and Gates controlled by an external Modular Synthesizer.

I think that’s about all you can really do with that aside from reprogramming the flash of the chip which is basically impossible. “

Crazy awesome DIY pedals.

While doing some research for GetLoFi I came across a spectacular page full of DIY guitar effect pedals. The contains not only neat pictures and sounds but also schematics and inside shots that will make you drool all over the keyboard. Everything seems fairly simple with some amazing sounds. The Tri-negistor was my favorite, all transistor device that uses negistors and negative resistance to oscillate like crazy. Each pedal is very well documented and referenced. There are also a few mentions of the StompBox Cookbook with pictures and schematics.
[Found through]

*Updated 03/09/2010 * Fixed the URL; schematics seem to still be up