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

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

Post by CoffeeTones » Thu Jan 19, 2023 8:32 am

:thumbsup: :toast:

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

Post by georgesvigneron » Fri Feb 03, 2023 7:16 am

Hello everyone,
I've been looking on the page 140 of this thread but links are broken :?

I own an AFD100 but I know it will die at some point (everyone I know who owns one had to repair it at some point), knowing the BIAS pcb is likely to die on me.

I was thinking about buy a plexi 100w kit and apply the 34# mod on it, I know a guy who's very talented at building amps so will most likey use his services...

Do we know a working and approuved #34 schematics for a 100w plexi (4inputs ) ?

Many thanks for the help ! :)
Georges

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A

Post by georgesvigneron » Fri Feb 03, 2023 7:41 am

Hello everyone,
I own an AFD100 but I know the amp is very fragile and a lot of them went to repair.
I would like to sell it and buy a 100w Plexi kit and apply the 34# mod.
I've been looking on the 140th page but I can't find any working links.

I have a very talented friend that would build the kit and do the mod but I need to find the schematic first.
So the base would be a 100w Plexi (4 inpus), not a 2203 or 1987.

Are those schematics available or do we have an update regarding those ?
Thanks to everyone :)
Georges

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

Post by gibsonclassic2001 » Sat Feb 11, 2023 12:16 pm

dukeamps wrote:
Thu Jan 19, 2023 6:17 am
reychapa wrote:
Mon Jan 16, 2023 11:45 am

I keep this tone.. really good :hairband:

Congratulations Duke
:toast:
34 + mystery stage
Is this a 34 with a mystery stage?
Impressive Nigel!
How much of the 34 circuit is kept?
If its just a 34 with a extra stage ill need to open up the old 34 I got from you.
I never got that 34 mod with extra stage to work back in the day. I always changed to many components like the 34 tail etc.

Edit.
Checked my 34/36 amp that got a bunch of switches.
Its a 34 with a 10k100n10k 3rd and 5n bright cap and 10k tail.
Got 22n/2n2 on switch for the first stage

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

Post by dukeamps » Sun Feb 12, 2023 8:41 am

gibsonclassic2001 wrote:
Sat Feb 11, 2023 12:16 pm
dukeamps wrote:
Thu Jan 19, 2023 6:17 am
reychapa wrote:
Mon Jan 16, 2023 11:45 am



I keep this tone.. really good :hairband:

Congratulations Duke
:toast:
34 + mystery stage
Is this a 34 with a mystery stage?
Impressive Nigel!
How much of the 34 circuit is kept?
If its just a 34 with a extra stage ill need to open up the old 34 I got from you.
I never got that 34 mod with extra stage to work back in the day. I always changed to many components like the 34 tail etc.

Edit.
Checked my 34/36 amp that got a bunch of switches.
Its a 34 with a 10k100n10k 3rd and 5n bright cap and 10k tail.
Got 22n/2n2 on switch for the first stage
I have sent you a PM.

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

Post by CoffeeTones » Mon Mar 20, 2023 10:59 am

georgesvigneron wrote:
Fri Feb 03, 2023 7:16 am
Hello everyone,
I've been looking on the page 140 of this thread but links are broken :?

I own an AFD100 but I know it will die at some point (everyone I know who owns one had to repair it at some point), knowing the BIAS pcb is likely to die on me.

I was thinking about buy a plexi 100w kit and apply the 34# mod on it, I know a guy who's very talented at building amps so will most likey use his services...

Do we know a working and approuved #34 schematics for a 100w plexi (4inputs ) ?

Many thanks for the help ! :)
Georges
https://www.google.com/url?sa=i&url=htt ... AdAAAAABAE

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

Post by tpruitt » Wed Mar 22, 2023 8:26 pm

Is there a #39 mod that correct out there?

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

Post by dukeamps » Thu Mar 23, 2023 9:16 am

tpruitt wrote:
Wed Mar 22, 2023 8:26 pm
Is there a #39 mod that correct out there?
yep

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

Post by tpruitt » Thu Mar 23, 2023 10:20 am

Mind helping me locate it?

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

Post by dukeamps » Fri Mar 24, 2023 3:17 am


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

Post by tpruitt » Fri Mar 24, 2023 6:59 am

Thank you.

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

Post by Antonio » Sun Apr 30, 2023 8:46 pm

Hey guys!

I built a #36 SIR amplifier based on all the information in the 765 pages of this thread. I came to the following conclusion:

- V1a
Hot shield trick and 33k resistor
2.7k /.68uf
220pF/100k treble peaker
0.022uF coupling cap

470k / 470pF on preamp gain pot with 5000pF bright cap

-V1b
NO shield trick
10k /0.1uF
0.022uF coupling cap

Straight to second gain pot without bright cap

-V0a
NO shield trick
10k/0.1uF
0.022uF coupling cap

stock 470k / 470k / 470pF

-V2a 820R

250pF/33k tone stack

0.68uF presence

4ohm / 100k NFB

6550s with 150k resistors for bias

I have a lot of gain and some excess bass. What am I doing wrong? Maybe the coupling cap of V1b (first stage) should be 0.0022uF? Maybe reduce the bright cape to 1n?

Could you help me with this?

Thank you very much!
Gibson Les Paul 1959 R9 "Jessica"
SIR #34/#36 Amp Replica

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

Post by CoffeeTones » Sun Apr 30, 2023 9:01 pm

use 1n bright cap, 500p treble cap in tone stack instead of 250p with the 33k slope, 150k or 220k from gain 1 wiper to ground, 5k/.1u presence, or 25k/4k7/.68u presence, try 68k NFB on 4r tap or 100k on 8r tap.

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

Post by Antonio » Mon May 01, 2023 10:36 pm

CoffeeTones wrote:
Sun Apr 30, 2023 9:01 pm
use 1n bright cap, 500p treble cap in tone stack instead of 250p with the 33k slope, 150k or 220k from gain 1 wiper to ground, 5k/.1u presence, or 25k/4k7/.68u presence, try 68k NFB on 4r tap or 100k on 8r tap.
Hi Coffee!

My presence is 25k/4k7/.68u and I have a 100k linear potentiometer in series with a 27k resistor for the nfb (4 ohm tap). This way I can adjust from 27k to 127k.

Is the correct bright cap 1n? I followed the logic that 77 JMP #36 would have come with 5n.

Even with these stage settings (2k7/.68uF +10k/.1uF + 10k/.1uF) is the 150k resistor required for ground?

For the tone stack wouldn't 250pF be correct?

Thank you so much!

Kind regards,
Antonio.
Gibson Les Paul 1959 R9 "Jessica"
SIR #34/#36 Amp Replica

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

Post by CoffeeTones » Tue May 02, 2023 12:12 am

1n bright because that is the right voicing and because 5n makes that gain control unusable and impractical for a high gain amp. Hence too much gain, too soon.
The 150k may not be necessary with the 1n bright cap where gain is concerned but it gives bass reduction and some gain reduction. Set gain 1 and 2 around 6, EQ the rest of the amp and there is your AFD sound.
500p in TS is correct.
56k, 68k or 100k at 4r settings for NFB - whichever you like. 100k = more gain, bass and looser feel
Use .1u or .68u presence cap, depending on which you like best. .68 is more gain and bass, .1 is more sizzle and treble.
You then only have to voice stage 2 and /or stage 3 cathodes to your liking.

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