Putting a gain control on the Mini Muffin

[Tremster]

Hey,

what would one do if you wanted to have not just the volume knob on the Mini Muffin, but make the gain adjustable?
Just using a pot for R2? If so, which value?

JMK pedals had a PCB for this years ago, with gain and volume knobs. Theirs was the transistor version of the Muff Fuzz, not the IC version (Mini Muffin).

Thank you!

Edit:
Oh Geez. Too many options being discussed on this topic.

 

[manfesto]

A good starting point would be to replace the 470K resistor with a 500K pot, that sets the amount of gain for the first op amp stage

 

[Tremster]

Cool. Thanks!