I've recently modded my '77 JMP master volume to a Friedman's Brown Eye spec, or as close as I could since there's no "oficial" schematics around, so I had to dig in photos around the net and try many variations.
I'm very impressed with the results and I think is the ultimate marshall mod.
I've recorded some clips. I couldn't capture the sound as good as it is in front of the amp, but you can get the idea.
First clip: Gain around 8-9, all around 5 in the EQ
https://soundcloud.com/josecarbia/be-rockness
Second clip: Gain around 4, some more bass in the EQ and the rest relatively flat.
https://soundcloud.com/josecarbia/be-acdc
Third clip: SAT switch engaged, gain around 9, bass rolled off to 3, treble and presence to 6, mids at 5.
https://soundcloud.com/josecarbia/be-jivi
Just to finish I have to congratulate Dave Friedman. I think his circuit is SO GREAT.
Ah, and don't ask me to post an schematic, I think Dave's work deserves to be kept in secret.
