I want to buy a big muff to have in the studio. I've seen 3 types: Black
with Yellow writing, silver muff (american model or something) and the green
one (which is not being made any more).

A friend told me that the Green one is the best sounding. But out of the
other two readily available what is the difference between the two? No
literature I've found on them says how they differ. Someone told me one is
for guitar and one is for bass, but which one.

I suppose what I really intend to use it for is bass in rock songs or for
the odd trashy guitar thing where you need crazy fuzz. But primarily I love
them on bass.

thanks,

Martin