Marshall JTM45/T of many gains

[Reeltarded]

Requested information on my Bruisemaker amp

Rear input to 33k grid stopper mounted at pin

Stage 1
100k plate
2k7 bypassed with .68u or 25u
.022 coupler
Gain 1MA
6 position bright selector (off, 50p, 120p, 500p, 1kp, 2k2p)

Stage 2
68k stopper
100k plate
2k7 bypassed .68u
.022 coupler
100k divider mounted to gain input
Gain 1MA
470k(470p peaker)/470k ground divider network

Stage 3
82k grid stop
100k plate
10k cat thode meow
.22 coupler
Gain 1MA

Stage 4
33k grid stop
100k plate (this is CF driver stage)
2k7 bypassed .68

100k CF


TS is Marshall config with 100k variable slope +47k (47-150k)

Master volume (1MA)


PI
.22u (!!!)100k with 820R (I think 820 last iteration
120/133k instead of 82/100k plus 10k balance trimmer
umm 12k tail

Output
150k grid leaks
.022u couplers
5k6 stoppers

Plexi style .1u pres control
1MA Res control

Nothing special about the stages except for how the gain is staged. Common settings would be (three preamp gains and bright)

4-6 with 120p, 7 to 10, 5 to 7 and Master between 4 and 6. Slope @82k. This sounds like Gary Moore is about to crap his pants.

First gain never goes over 7 and there is always a bright engaged if not playing straight up jazz

Other settings vary from that to

Master at 10, gains are 3-4, G2 3-7, G3 is master. This balanced with slope, resonance, and brights is every sort of tweed and even vox. Brian May crunch to insanity on the guitar volume. Really does a tweed Deluxe convincingly.

It becomes a flute when you dime G2, moderate G1 with small bright, Master @ level just under collapsing NFB and g3 until it's smooth and reactive. Legato machine.

Oh. 47k NFB to 8R tap

[10thTx]

EDITED and reposted the schematic after helpful corrections!

with respect, 10thtx

[Reeltarded]

Oops I left out a plate snubber over the second stage plate. 330p.

It has a Jose clipper circuit too that I didn't mention because it's a toy. No master, just a 10k and a .22u cap off the CF with two arrangments of 1n914 diodes. (note: for fun I bought a pair of amperex germanium diodes, a pile of other glass germaniums, and a few odd other SI diodes to mock a Klon Centaur in one switch position. We will know next Tuesday according to package tracking. SI to opposing parallel amperex pair at CF and a pair of the other germaniums opossed parallel over the Master control)

Bright is situated just like a bright cap.Whole switch is over the 1st gain control signal in and out as you placed it.

The LTP has .22u instead of a .022u and .1u. The 100ks replace the 1Ms. RC constant remains.

You placed the .22 correctly in the PI but the .022 on the other side is also .22u.

Yeah, that is pretty much this amp. I have two similar. I never got around to converting the other to this circuit.

Here is resonance!

E6794CDE-466D-47DF-8AB8-8AE235924221.jpeg

[10thTx]

THANK you again for sharing the schematic arrangement for your amp! Very generous of you!

Very grateful for your contribution to the TAG forum and sharing this with us! The YouTube video of that Marshall was absolutely stellar!

I've attached an editable ExpressSCH schematic that can easily be revised ............ or Windows paint could be used. The SCH schematic has a 2nd page with PT, bias and B+ rail which are likely ALL incorrect but could be edited also.

PLEASE NOTE this statement as the Jose clipper is not in this schematic (and I am not certain how to draw this arrangement):

It has a Jose clipper circuit too that I didn't mention because it's a toy. No master, just a 10k and a .22u cap off the CF with two arrangments of 1n914 diodes. (note: for fun I bought a pair of amperex germanium diodes, a pile of other glass germaniums, and a few odd other SI diodes to mock a Klon Centaur in one switch position. We will know next Tuesday according to package tracking. SI to opposing parallel amperex pair at CF and a pair of the other germaniums opossed parallel over the Master control)

Respectfully, 10thtx

[Reeltarded]

Oops missed slope ad a 47k as a bottom stop. 47k plus 100k pot there.

This amp rocks.

[10thTx]

Further edits below ..........


With respect, 10thtx

[Reeltarded]

Tone stack connects in normal place. Jose string also connects same point,

10k, .22u, switch, ground. Holy cow. I forgot there is a squash control. Add 25k pot at ground end of string lmfao

There is no thru-path.

One side of switch is a pair of opposing 1n914s, other side single 1n914.

[10thTx]

I am appreciative of the descriptions and direction. Having said that, you are describing things I have NOT familiar with at all ............. so I really am just making guesses and lack
confidence that I am drawing things correctly? I have never heard of a Jose clipper mod before your mention of one in a post?

IF you are still seeing errors, please consider printing off the GIF file and marking the corrections on it and then reposting it with your noted corrections. If you do that, I'd be happy to edit the schematic to match. Grateful for your generous information and contributions. Thank you!

With respect, 10thtx

[Smitty]

Thanks for sharing. Is this the same as the Nate Telow Marshall?

[Reeltarded]

No! That is a Dumble UP.

Notions of scheme but no confirmation.

[ViperDoc]

How do you like the diode clipping circuit?

[Reeltarded]

I have it in half my amps, it has been in most of them at some point. It helps do something that no one describes. With the amp raging but squashed about 20k it sounds like a screaming animal vocalizing. You know how George Lynch touches the guitar.. like that. There is a zen of volume vs squash. It sounds like it's melting but clean enough to articulate and hyper-harmonic.

If you have crappy tubes it doesn't care. Jose doesn't care if you use JJs. hahaha