Guys, been trying a lot of stuff in my metal panel JMP50 but I'm not getting the results I want... Looking for a classic hot hodded marshall tone like old accept's tone, or some old bogner modded marshall tones, but I don't want to add an extra tube nor make it a 4 stage plate fed, mainly because somehow I want to keep a low input working as a clean-ish channel (bypassing 1s stage). I was wondering if you guys can point me to a mod that really works for that... just pure simple specs, no need for footswitchable channels or what so ever, I want to keep it as simple as possible.... Any Ideas? It's like this now (and sounding too squishy with gain past 6 on both pots - it's a 4 holer)
1st stage:
100k plate
3k3/1u
470pf/470k + 47n coupling
1M pot
2nd stage
470k/470pf grid stopper
100k plate
820r/.68u
47n coupling
1M pot
3rd stage
100k plate
820r/.68u
TS and the rest are stock plexi specs... it also has a variable NFB 1Mpot in series with a 100k @ 4ohm tap (this is working fine). NO PPIMV and no intention of adding one unless it is crucial to fix problems like high end squish or flubby low end , etc....
Thanks !!
3 stage+cf hot hodded marshall tone - HELP
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3 stage+cf hot hodded marshall tone - HELP
76' JMP 50w w/ 71' metro board
93' Fernandes SSS strat
93' Fender Japan HSS Strat
4x12 w/ 2x 25w rola creambacks /2x 25w m75 Scumbacks
93' Fernandes SSS strat
93' Fender Japan HSS Strat
4x12 w/ 2x 25w rola creambacks /2x 25w m75 Scumbacks
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Re: 3 stage+cf hot hodded marshall tone - HELP
you could try raising your plate resitor/s to 150k or 220k . doyou have a bright cap on your gain pot? try a 1n or 5n
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Re: 3 stage+cf hot hodded marshall tone - HELP
You likely need m ore attenuation between stages, especially second to third. Also, roll off as much low end in the preamp as you can bare to lose and bring it back later in the circuit. Otherwise, blocking distortion becomes an issue.
There is a ton of gain from three gain stages. Surely enough for old Accept tones.
Your third gain stage is going to be hit hardest and clip earliest. Keep an eye on how input signal drives the cathode voltage lower. You'll hear a point where things get mushy and bad distorted. Use attenuation to keep things just shy of that point. You can also use a zener from grid to cathode to clamp this as outlined in Merlin's book.
Good luck!
george
There is a ton of gain from three gain stages. Surely enough for old Accept tones.
Your third gain stage is going to be hit hardest and clip earliest. Keep an eye on how input signal drives the cathode voltage lower. You'll hear a point where things get mushy and bad distorted. Use attenuation to keep things just shy of that point. You can also use a zener from grid to cathode to clamp this as outlined in Merlin's book.
Good luck!
george
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Re: 3 stage+cf hot hodded marshall tone - HELP
Thanks a lot George! I've been doing some research on 3 stage circuits and have some ideas... most of them use dividers to attenuate signal before the grids between stages and bigger ck at the last preamp stage to bring back some low end.... will mess with that and let you guys know the results.
Thanks!
Thanks!
76' JMP 50w w/ 71' metro board
93' Fernandes SSS strat
93' Fender Japan HSS Strat
4x12 w/ 2x 25w rola creambacks /2x 25w m75 Scumbacks
93' Fernandes SSS strat
93' Fender Japan HSS Strat
4x12 w/ 2x 25w rola creambacks /2x 25w m75 Scumbacks