Big muff

[AndyG]

Is there a way to get the sustain and drive of a muff but with tighter bass?

Andy

[petemoore]

  muff mod threads, tons.
  "Yun"..
  Some people reported downsizing the value of all the SP caps by a factor of 10x smaller does that.
  Stick a cap in the input wire [splice]. Adding a series capacitor reduces value, two equal value caps = 1/2 the value.

[bumblebee]

Reduce every second 1uF cap to a .1uF cap. If you still want more reduce the others.

[R.G.]

I like reducing only the blue colored caps. 

[petemoore]

  yea, well, you're biased..
  and I like to type, breadboard.
  take a look at all the links, find what caps in series with or in parallel to the signal path do.
  Are they shunting highs to ground? Are they High Pass filters in the SP ?
  Then figure any time you see one like 'that' [say a high pass filter in this case] you can make it go up or down from wherever it is 'indexed' now, in value...related to voice, smaller values raises the frequency at which X amount of attenuation is applied to the bass content of the signal.
  Then take into account that what the last transistor sees is multiplied by the last transistor [once], what the input transistor sees is multiplied [amplified] by all 4 stages, each gets the chance to boost, two have clipping distortion, reducing bass here may make the later sections less prone to being 'swamped' by bass distortion, however there may be some use for allowing some of that activity, you can always add the HP later.

[bumblebee]

IMO its best to leave the 1uF caps in series with the diodes at 1uF, going to .1uF - .047uF results in a boomy horrible sounding big muff, I forgot to mention this in my first post. Sovteks have this value here and its the first thing i swap out on them.