Thanks for the reply, I built my version with the 'animal' style bost switch and a 250k instead of 500k gain and 50k bass pot, will changing to a 25k bass pot make much difference?
I don't know. I doubt it, but at least you know that if you don't like it you can just solder a 47K resistor across the outside lugs of the bass pot to try it too.
Just built this up and it sounds fab! One thing though, is it normal that the volume is always above unity, even when on 0? This is a loud pedal, but the volume doesn't seem to have much sweep.