Chico Fuzz
I recently was given a dead handmade fuzz (no schematics or any info whatsoever) for repairs. I drew its schematic and found it quite interesting and unusual, so I’ll share it here. The input stage is a shunt-feedback common emitter with a little bit of emitter degeneration and the fuzzy section at the end is based on the CD4049UB CMOS inverter. The weird part is it’s middle “tone” section, which is a full Crybaby style wah-wah down to the component values. The classic circuit can be seen here, and I found the specific 82k//4.7u combination in this one. The pedal resides in a stompbox (interestingly covered by mirrors), so there is no wah pedal, just a potentiometer. Another unusual choice is the inductor used; in this circuit it is actually half of a small step-up transformer (maybe from an electric flyswatter?). I haven’t measured it’s inductance, as I didn’t want to take it out of the PCB, but I guess it should be around the usual 500mH seen in the Crybaby. The end result is a very unique sounding fuzz.
