Mods for my 2204 build - switchable JEL and #34?

SpiderWars said:
Yeah I hear you on the more classic sounding Marshalls.

Are you also trying boosts with the mods? When I did my version of the JEL I wanted to be able to just have a stock 2203 so I could boost it with an SD1. That's still probably my favorite tone out of that amp but the tweaked JEL mode is really close.
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Yep, I like it with an SD1 or TS out front. What tweaks did you do to the JEL mod?
 
ledvedder said:
Yep, I like it with an SD1 or TS out front. What tweaks did you do to the JEL mod?
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Mine was a slight compromise due to the dual input jacks (extra 1M to ground there) and extra gain control for the Lo gain modes. So I increased that 220k to ground to 330k and added the 470pF snubber across it. The fat cap is only 5uF but I doubt that sounds much different than the 25uF Dave used.
 
SpiderWars said:
Mine was a slight compromise due to the dual input jacks (extra 1M to ground there) and extra gain control for the Lo gain modes. So I increased that 220k to ground to 330k and added the 470pF snubber across it. The fat cap is only 5uF but I doubt that sounds much different than the 25uF Dave used.
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Since you’re more familiar with the JEL I think I’ll bow out now and let you fill in from here Matt. The circuit I built isn’t an anything - it’s my own design.
 
I've been comparing some hot-rodded Marshall schematics, and I notice some have a 0.0022uF cap on v1a, while others have it on v1b. Is there a noticeable difference either way?
 
ledvedder said:
I've been comparing some hot-rodded Marshall schematics, and I notice some have a 0.0022uF cap on v1a, while others have it on v1b. Is there a noticeable difference either way?
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Jeremy mentioned this earlier in your thread somewhere. Basically some amps like one location of a smaller coupling cap over the other. Personally I use a small cap after the 1st stage not the second, but that’s for stability reasons and less tonally. Try both and see what you think.
 
Some even have all couplers and cathodes up to the PI at .0022 and 2.7 // .68, like BE100/Marsha. Seems like it would make a fairly bright sound with hardly any bottom end, but I guess at that point it starts to depend on the rest of the circuit and the anticipated speakers being used.

I've [accidentally] tried .0022 at both positions, but didn't really notice a tonal change
 
Just a small note. Every modder is trying to beat the shit out of an amp. But nowhere I have seen to mention a capacitor at the input, before the first stage. The behavior of the first stage depends on its presence and capacitance too, especially with passive high output pickups. But maybe I just didn't notice that, modding is not exactly my hobby.
 
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