Big Muffs and Pot Values

[trad3mark]

Hello all!

I'm starting work on a Muff today. I've some nice russian germanium diodes and transistors, and i've been meaning to make one for a while now. I'm basing it on the Violet Rams Head model, cos i think it's smoothness will be a nice contrast to the Muff I have at the moment; the one with Tone and Wicker.

I've a little question about the pot values though. I know the Muff calls for 3 100k pots; 2 logs and 1 linear one. I understand the relevance of the tapers, and that's grand, but what about the values? I know that having a larger value for Volume will make it louder, but what about for tone and sustain? To be honest, changing the values for Volume was the only one i ever understood with pot values. I always try to stick with what's already there, but in this case, i just happen to have loads of values that aren't 100k. I know i could use resistors across the pots to get it to 100k, but what about putting in other values?

Cheers,
N

[John Lyons]

Linear pots all across is what I like.
The originals used these as well.
The Sustain pot is best at full up. With a linear pot you have a better range, bringing the
"good" range more towards the center of the pots travel rather than all at the end.

The stock BM has plenty of output level. With a Linear taper pot on the volume control
you get unity around 12 o'clock, perfect! With Audio taper unity is past noon...maybe 2pm.

Back to your question.
Making the pots larger will change impedance and maybe more output, but you don't need that anyway.
Making the Sustain pot larger will make the pot work "slower". The gain will still pile up at the end...
even more so.

You can use a 50k pot for the tone and then 25K resistors at each outer lug. This narrows the tone sweep
(a good things since it's not that useful) and gives you a wider sweet spot. (don't tell anyone).

John