Kapo_Polenton
Well-known member
What is the secret to tight bass when you are doing gain mods? I wanted to hotrod one of my 2204 builds because I have a PTP and it is easy to play around with things. I have done the following;
common fat/lean switch (.022 vs .0022) on first coupling cap. Maybe I need to go even tighter?
fixed resonance off the NFR Friedman style (220k, 0047 cap) coming off my 47 K resistor to 4 Ohm tap.
V1 plate resistor value 110K in series with 220k for total 330k.
1 uf cap over 820 R on V2
V1b 10K to 5K on a switch for more gain
It all sounds good when the preamp is set to around 7 but after that, it goes to mush at around 9 and sounding almost like a fuzz at full gain. I also tried a .68 bypass cap on V1b and I got some oscillation. ( I know 100-500 pf cap over the 330k in V1 is supposed to help with that but its still messy sounding) I’m just wondering what additional tricks of the trade are used to keep it all from falling apart at higher preamp/gain settings? I look at the Friedman and Ceriatone stuff and I know their circuits are even more gained out. How is it not woof city when dimed? Or do those circuits sound crappy/ fall apart past 8 as well? I thought of maybe just bypassing the 10K resistor on V1b with a 1uf as I know that crisps it up but I am interested in how other hot rodded Marshall style amps accomplish this.
Thanks amp nerds!
common fat/lean switch (.022 vs .0022) on first coupling cap. Maybe I need to go even tighter?
fixed resonance off the NFR Friedman style (220k, 0047 cap) coming off my 47 K resistor to 4 Ohm tap.
V1 plate resistor value 110K in series with 220k for total 330k.
1 uf cap over 820 R on V2
V1b 10K to 5K on a switch for more gain
It all sounds good when the preamp is set to around 7 but after that, it goes to mush at around 9 and sounding almost like a fuzz at full gain. I also tried a .68 bypass cap on V1b and I got some oscillation. ( I know 100-500 pf cap over the 330k in V1 is supposed to help with that but its still messy sounding) I’m just wondering what additional tricks of the trade are used to keep it all from falling apart at higher preamp/gain settings? I look at the Friedman and Ceriatone stuff and I know their circuits are even more gained out. How is it not woof city when dimed? Or do those circuits sound crappy/ fall apart past 8 as well? I thought of maybe just bypassing the 10K resistor on V1b with a 1uf as I know that crisps it up but I am interested in how other hot rodded Marshall style amps accomplish this.
Thanks amp nerds!