Guitar with built-in synth fuzz pedal

[Timodon]

Hello there

Although this technically isn't a DIY synth it's based on a Hex-Schmitt so this seemed the most appropriate place to put it.

It's my guitar with built-in homemade fuzz pedal. This project took me a couple of years to fully realise (i started before I got into circuit-bending) and it's been through three different incarnations to get here, but I'm really happy with the final result.

The Fuzz pedal is based on a design from the Nic Collins book with a few additions I made myself, the main one being that as well as clipping the signal with the Hex-Schmitt the oscillator is also running so it fights with and sometimes tracks the guitar signal. Here it is in action. The basic sound from the amp is fairly crunchy to start with but you can still hear some of the sounds this pedal produces. Warning, it's a noisy beast!:-

War Bastard.mov

hope you enjoy!

[Remork]

way to revive an old thread.
any explanation on the controls?
sounding great!

[stealthbopper]

Fantastic sound, inc the end dive upwards! Nice

[Timodon]

Thanks for the kind words, sorry for the late reply

The silver knob is the oscillator pitch, the first white knob is volume. There's a choice of insertion point into the fuzz circuit for the guitar signal controlled by a rotary switch (the second white knob), offering differences in tone and response. The spring loaded button is wired to add a resistor to the oscillator circuit giving the pitch of the oscillation an instant drop, switching it in and out quickly gives a step filter-ish sound. Then there's a true bypass switch.

The biggest problem with this (and all Hex-Schmitt based synths that I've heard) is it's extreme ear-raking harshness at higher osc frequencies. This is certainly one application of this sort of circuit where a Lo-pass filter would come in really handy, one day I've promised myself I'll build that extra circuit and incorporate it into my guitar. Space is really at a premium in there though!

[Timodon]

Almost forgot to mention - the patch cord across the front! It's been a while since i used the guitar in anger.... that was to let me repatch things on the fly and plug my keyboards into my guitar and have them go through my multi-FX and come out the amp. I used it this way on stage a good few times, lots of fun!