Chubbs
Well-known member
My bad I can’t keep all the SIR mods straight. The one I meant to reference is the #36. It adds a gainstage between v1 and v2
glpg80
Well-known member
Yeah I’m not copying anything from anyone. What I offer is a complete NFB EQ - lows, low mids, and highs. I also have an excursion switch to give the dizzying shaking low end. Definitely agree some type of control is needed because it’s so necessary at volume.
SpiderWars
Well-known member
One thing to keep in mind and something it took me a while to appreciate…that 10k cathode resistor…when boosting the front end…is special. You can go lots of different directions there but when boosted just right the JCM800 boosted is amazeballs. Just ask our friend Euge.
FourT6and2
Well-known member
OP here is asking for some ideas about how to mod his 2203 kit amp that he built. This isn't about how you choose to build your own amps. Not every thread we post in has to be a competition about who offers the best advice or who builds the best amps...
glpg80
Well-known member
I’m sorry - you made it sound like in the past 40 years it’s quite common, and I was not fully aware of the terminology, so it’s certainly value to the thread. I’m just feeding ideas on mods that I do just as you’re posting mods you do. Explain to me where the pissing contest is please?
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ibzprestige
Active member
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jasonP
Well-known member
Thats a nice build you got there, it's a perfect modding! I have some schematics of a lot of amps and modded ones I could post up for ya if wanted.
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ibzprestige
Active member
Thanks! Feel free to post them or send them in PM. I appreciate it!
jchrisf
Well-known member
Post em'!
glpg80
Well-known member
I agree with others that’s a very clean build with great components. Would make a great candidate.
I think I have an SIR #36 schematic somewhere I can send in PM if you decide to go that route?
I think I have an SIR #36 schematic somewhere I can send in PM if you decide to go that route?
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ibzprestige
Active member
Thank you! Sure, send it over! Kind of weighing my options still on where to go with it
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ibzprestige
Active member
Any one have any ideas how to get maybe into Bogner blue channel territory?
WarHed
Active member
You would need another gain stage for that. The JEL or #34 circuits are good references for about as hot as you can mod a 2204 topology without going diode clipping/Jose
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jasonP
Well-known member
Looks like you have space for another 12AX7 for 2 more gain stages, just depends on what you want to do. The BE circuit sounds great in my opinion and do a couple things to make it slightly different by using a Rivera focus control in the feedback loop and resonance control (like the BE Deluxe) and take off the snubber (470pf) off the plate of the CF use 150k bias grid resistors. I like using 1M/.0068uf on the resonance control. Gives the amp a little more aggressive and tighter sound. I like it for when you don't want to add another 12AX7 and this circuit cleans up really well with the volume. I have a bunch of schematics you just have to give an idea of what direction you want to go.
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ibzprestige
Active member
Well this will be my first time adding in another gain stage without going off of schematic and layout, so if you have a schematic that’s fairly straight forward that I won’t be banging my head against the desk trying to figure out, I’d be up for that! Haha. I like how simplistic the 36 mod seems…not sure If it’s a tone I will like or not. I do like the Friedman sound for sure.
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