Ge 4 Big Muff - how are the 'bias' and 'volts' effects achievd?

[ribolovec2]

Hello guys..
I've been looking for a schematic of the pedal mentioned above for days in order to see how are those effects accomplished. As i haven't found anything, I'm asking you for help. Is the 'bias knob' just changing the bias for the whole circuit (for example form 50% from the input volatge to, say, 20, or sometihnig) or is it more copmlex? And another thing - is the 'volts' knob just reducing the voltage, or is there some more complex circuity? That's what I suppose these knobs could do, but it sounds suspiciously simple. So, would you please help me?

[Taylor]

I'd guess the same.

Distortion pedals are almost all really simple. Simple is good business. Since a 2k pot wired as a rheostat between the power jack and the +v rail works, it's good. Make the bias resistors at the front end of the pedal a pot - it works, so it's good. They probably have fixed resistors on either side of the bias pot (one from lug 3 to v+, one from lug 1 to gnd) to make sure the user can't do anything too weird.

I doubt you'll see a schem of it just yet as it's new, but I think you're on the right track and I'd recommend you try those mods to a muff clone and see where they take you.