Control for a fuzz pedal is based on the Fuzz Face circuit

[TimothyEngram]

Hello, I am trying to build a fuzz pedal based on the Fuzz Face circuit, but I want to add some extra features and controls to it. I have found some schematics and layouts online, but I am not sure how to modify them to suit my needs. I have some basic soldering and electronics skills, but I am not very experienced with designing or modifying circuits.

How can I add a tone control, a bias control, and a switch to toggle between germanium and silicon transistors to my fuzz pedal?

[abc1234]

Tone control - It depends on what you want to achieve. If you want more clarity for chords, you can lower the input cap so low frequencies are attenuated when entering the circuit. Then put the original cap in parallel with this new one, but in series with a pot so you can reintroduce lows at a level of your choosing, aka control the tone.

e.g.

Code Select Expand


    Original Cap
     ¦--||--pot--¦
     ¦           ¦
In---¦--||-------¦------
     New Cap


Bias control - Replace the resistor connected to Q2's collector with a pot.

Switch between germ and silicon transistors - On/On DPDT switch connected the collector and emitter of each pair (e.g. the C and E of Q1's germ and silicon transistors; the same for Q2's). This would allow you to have combinations of germ + germ, germ + silicon, silicon + silicon, and silicon + germ. If you just want to switch between germ + germ and silicon + silicon, use a On/On 4PDT switch.

[antonis]