Marshall JCM 800 4010... mods

[Garydean]

I've been pokin around trying to obtain a tone solution to this line of Marshall amps. I get one in every once and a while. Usually it's the 6550, 50w combo version with the jacks soldered to the circuit board. Beside clipping out the brite cap, which works, what have you guys done to warm these buggers up?

thanks,

Gary

[drewl]

Remove the treble peaking circuit (470k/470uf combo)
Change the tone stack slope resistor
Bypass V1B 10k cathode resistor with a large value cap (increases gain also)

Search for the Viva Analog site they have alot of great Marshall mods.

[Garydean]

Thank you. I down loaded and printed out pages and pages of ideas. Trial and error at this point to see what sounds the best.

thanks again,

Gary