Why does the Tone Wicker Big Muff have a 2.2uf in front of the EQ ?

[Iplayloud]

There's a million pages/threads covering how to do the tone bypass mod, from lifting C8 and R5 or just going around completely, but none of the mods suggest adding a cap before. Why would the actual Tone Wicker pedal from EHX have that cap? Also the Op-Amp Muff from 1978 had a tone-bypass switch, and the bypassed circuit also added a 150n cap (c14). None of the mods suggest adding this. Any reason?

Tone Wicker schematic (C8):
http://mirosol.kapsi.fi/wp-content/u...EHX-BMPwTW.jpg

[Iplayloud]

Another example of not just bypassing the EQ but adding caps:
http://www.bigmuffpage.com/images/sc...0schematic.jpg

[Helmholtz]

Not quite sure what exactly you mean.

The coupling cap C8 before the EQ makes sense to avoid SW3A popping.
The larger its value the lower the bass cut-off frequency.

Just try different values to find out what you like best.

Your second circuit example shows a circuit having higher input impedance after after the EQ, so lower cap value makes sense.

[Iplayloud]

My point is the 40 other versions of traditional Big Muffs don't have a capacitor there at all. Only seems to be the 3-4 models with a tone bypass that have it. I'm about to try the tone-bypass mod so I was wondering if I should add this cap. Can you expand on the SW3A popping you mentioned? I tried to google it and didn't find anything. (Ok keep the switch from popping, got it thx)

[Helmholtz]

Another reason for the input coupling cap is to block DC from the tone pot, which would make it scratchy.
If there is still some switch popping, wire 1M resistors from the negative ends of C8 and C3 to ground.
That is after you reversed the polarity of C3 which is shown with wrong polarity (positive end should go to transistor base).
So the negative end of C8 should go to SW3A and the negative end of C3 should go to SW3B.