S.I.R. 100W SuperLead Schematic pt. II

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lespaul6
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Re: S.I.R. 100W SuperLead Schematic pt. II

Post by lespaul6 » Mon May 09, 2022 9:08 pm

CoffeeTones wrote:
Mon May 09, 2022 8:39 pm
Which scheme are you using? It's possible to do #34 with the master on 2 and the gain on 7 or 8, without a PPIMV. It's hard to give out much info, because too many folks want to start amp companies with other people's work. The Fender / Marshall / Jose trend continues, I guess. There's a guy who sells mostly other people's and company's mods, while pretending to be an expert authority. Sure, he changes a cap or two, sometimes throws a snubber cap here or there. Hard to believe people eat this sort of thing up.
:roll:
I agree... well Ive tried the 34 mod done by RJS and sold it, didnt sound good, too too bright. And I like bright. But this was just dumb and a depth knob was done to try and compensate, which brings in a bunch of other issues with the tone. Then I had friedman do his AFD mod and I didnt care for that either, didnt sound right. I see most other diy guys use a ppimv like the ceriatone afd, again, to most likely tame the high end... but the mod is not right.
I think the "issue" is finding a recipe that will allow you to use that .1uf cap without it overwhelming everything else and losing a balance to the eq/tone. Maybe I just need to do the 36 mod to fill out the eq and round off the strident nature of the 34?

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CoffeeTones
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Re: S.I.R. 100W SuperLead Schematic pt. II

Post by CoffeeTones » Tue May 10, 2022 3:52 am

Nah, the PPIMV just makes the #34 more usable and easier to stay in front of. That mod is unbearably bright and thin until you have the gain cranked way up. Built according to the Santiago schematic, that is just what the amp is when it's in the sweet spot.

A great, accurate #36 sound can be had without the added stage and the issues that come with that added tube.

On another note, I've been holding off, but will now say that everyone including myself, has been doing the 4 stage, #36 mod wrong. If that mod is done right, the amp will make the guitar feel unbelievable with an amp this bright and tight.

:rockon:

rockgod212
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Re: S.I.R. 100W SuperLead Schematic pt. II

Post by rockgod212 » Tue May 10, 2022 4:06 pm

CoffeeTones wrote:
Tue May 10, 2022 3:52 am
Nah, the PPIMV just makes the #34 more usable and easier to stay in front of. That mod is unbearably bright and thin until you have the gain cranked way up. Built according to the Santiago schematic, that is just what the amp is when it's in the sweet spot.

A great, accurate #36 sound can be had without the added stage and the issues that come with that added tube.

On another note, I've been holding off, but will now say that everyone including myself, has been doing the 4 stage, #36 mod wrong. If that mod is done right, the amp will make the guitar feel unbelievable with an amp this bright and tight.

:rockon:
so we have been doing the mod wrong? do tell in what ways. could it be that the xtra stage went before the 1st stage on the input side like a plexi xtra stage mod? could the 36 be more like a mick mars plexi amp mod to where there are 2 2.7k/.68 stages with the normal channel blended in?

a can of worms has been opened, lol.....
"purple power rules"

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Re: S.I.R. 100W SuperLead Schematic pt. II

Post by BRMSlash » Tue May 10, 2022 11:04 pm

I've changed spec again, back to a more typical arrangement. Also managed to get rid of the ringing/clanging sound on the intro of 'welcome to the jungle' by removing the MTK1813's in both my guitar & amp. Now using 225p in the guitar & MKT368 100n as cathode bypass cap. I've moved house recently so haven't got my recording gear set up yet.

1st stage: 33k, hot shield, 2k7/680n, 100k/220p, 22n, 2n2/1M pot, 1n/470k/150k.
2nd stage: 10k/100n, 100k/470p, 22n, 1M pot
3rd stage: 2k7, 100k, 22n, 470p/470k/470k
4th stage: 820R/470n

I still might bump up the 15k PI tail resistor to get a bit more compression.

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CoffeeTones
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Re: S.I.R. 100W SuperLead Schematic pt. II

Post by CoffeeTones » Wed May 11, 2022 1:08 am

BRMSlash wrote:
Tue May 10, 2022 11:04 pm
I've changed spec again, back to a more typical arrangement. Also managed to get rid of the ringing/clanging sound on the intro of 'welcome to the jungle' by removing the MTK1813's in both my guitar & amp. Now using 225p in the guitar & MKT368 100n as cathode bypass cap. I've moved house recently so haven't got my recording gear set up yet.

1st stage: 33k, hot shield, 2k7/680n, 100k/220p, 22n, 2n2/1M pot, 1n/470k/150k.
2nd stage: 10k/100n, 100k/470p, 22n, 1M pot
3rd stage: 2k7, 100k, 22n, 470p/470k/470k
4th stage: 820R/470n

I still might bump up the 15k PI tail resistor to get a bit more compression.
That likely sounds nice. I built a very similar spec. I accidently put a 180k plate resistor on stage 2 (10k//.1uF). Yeah, I didn't have my glasses on, and the color bands are kind of similar, LOL. The 180k was bypassed with a 250pF, X5F ceramic that measured at about 230pF, no bypass on stage 1 plate. I think you should give that a go and see what you think.
Last edited by CoffeeTones on Wed May 11, 2022 1:43 am, edited 2 times in total.

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CoffeeTones
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Re: S.I.R. 100W SuperLead Schematic pt. II

Post by CoffeeTones » Wed May 11, 2022 1:28 am

rockgod212 wrote:
Tue May 10, 2022 4:06 pm
so we have been doing the mod wrong? do tell in what ways. could it be that the xtra stage went before the 1st stage on the input side like a plexi xtra stage mod? could the 36 be more like a mick mars plexi amp mod to where there are 2 2.7k/.68 stages with the normal channel blended in?

a can of worms has been opened, lol.....
Man, I'd like to share the details, but I don't want this mod in someone else's line up. I want it to be clear that I am not referring to anyone who has been a participant / contributor in this topic for a long period of time. Not that I'm aware of anyway.

Unique
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Re: S.I.R. 100W SuperLead Schematic pt. II

Post by Unique » Wed May 11, 2022 2:01 pm

CoffeeTones wrote:
Tue May 10, 2022 3:52 am
On another note, I've been holding off, but will now say that everyone including myself, has been doing the 4 stage, #36 mod wrong. If that mod is done right, the amp will make the guitar feel unbelievable with an amp this bright and tight.

:rockon:
I have been hearing a lot of mice on tread mills since this comment was made. You might have just took this thread on a new turn...

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