HI all. Maybe someone can advise me on this. I've build a Fuzz Face clone but it had big hum with my normal power supply so I've put 470uf cap and 470k resistor on the power supply input. Hum is gone and I only get 0.5V Voltage drop so that don't bother me but is ok to put high value caps like this? It's not going to eat up battery or something other I've not noticed? Also is there a way the get rid of that cratching pot fuzz noise? My does it and I've noticed the original Fuzz Face does to. Thanks for any advice Jim
I am not sure if the original FF had a 9V zener diode to protect the circuit, and a 47uF capacitor to filter some noise, both connected from - to +. I think that changing the power supply filtering may have two consequences:
1) As alkaline batteries do sound a little different from ordinary ones because they have different capacitance and resistance, mods to the power filtering "MAY" alter the tone slightly. That is, the battery and the power supply are parts of the circuit.
2) About the voltage drop, you need to check the bias resistors to make sure that Q2's collector voltage is about 4.5 - 5.0V. If not adjust them until you get that values.
If you are happy with it use whatever trick you want to filter hum.
About the pot, I just leave it its maximun and use the guitar volume. I am considering to replace it with a fixed metal film resistor. But the protos I built with the pot did not have the problem you have.
