Distortion please...Amp Distortion
Xtrchessreal wrote:
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I have a DIY amp built to Marshall 2204 circuit specs that is about 15 years old now. I use it at my gigs. I want to experiment a bit.
A couple ideas I have barely researched but have in mind:
Add a post PI volume pot - Without seeing a schematic I believe this would allow clipping in the PI while attenuating the AC signal from the output tubes without affecting the negative bias.
** Easy way to do this is with a single, log pot wired between the EL34 grids.
The pot should be about 500kohms, log taper and wired as a simple rheostat.
Attenuating the NFB - Simply adding a pot to do this seems easy but I know there are risks with oscillations.
** I wouldn't bother, Marshalls have low enough NFB as is.
Reducing NFB does not usually cause oscillations - increasing it does.
I wonder what other mods I could play around with to achieve some amp distortion? I have room to add more preamp valves.
** Beware of that idea.
Pedals are your friends.
..... Phil
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