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Marshall Amp Layouts

Posted: 05 Apr 2012, 16:00
by sinner
...I'm working on them :roll: it

Any Marshall fanatics/lovers/knowing gurus here, who willing to help out?

This is great website about them http://folk.ntnu.no/roef/JTM100.html Most of my info I'm getting there.

I've started with version 7 and already have huge headache. What's the preamp filtering cap is? Some says it was 16+16uF multi section e-cap, other sources says it's 32+32uF

This is what I have already, still a lot of wiring left

Re: Marshall Amp Layouts

Posted: 05 Apr 2012, 17:35
by darthoverdrive
Here are a couple of sites that I used in the past when referencing Marshall amps, hope its what your looking for. :)

http://www.drtube.com/marshall.htm

http://www.marshallschematics.com/

I stopped building tube amps back in '08 when the economy took a shit but fortunatly I backed up all my links.

Re: Marshall Amp Layouts

Posted: 05 Apr 2012, 20:20
by Groovenut
Have you seen this one? I hope I am not way off base here...

Re: Marshall Amp Layouts

Posted: 17 Apr 2012, 17:49
by sinner
Alright. I left 100 watters for later, and I just finished my JTM45 layout with Star-Larry Grounding Scheme. Can you guys look at it and spot any mistakes?

Wiring is messy, but I hope it's clear enough

Thanks

Re: Marshall Amp Layouts

Posted: 18 Apr 2012, 06:08
by DrNomis
You could also try using 47uF/450V DC Electrolytic Caps for the preamp supply filter-caps the larger capacitance value shouldn't affect the tone much, other than reducing hum levels, originally, my little Legacy 5-Watt Class-A Valve amp used two 22uF/450V DC cap, and a 47uF/450V DC cap, but I replaced the two 22uF caps with 47uF caps, and the 47uF cap with a 100uF cap, result, the hum level (which was audible) was much reduced.... :thumbsup

Re: Marshall Amp Layouts

Posted: 18 Apr 2012, 11:59
by sinner
I'm not an expert of any kind, but AFAIK it does affect the feel of the amp, enlarging PI filtering should no affect the way this amp works.

Anyway, it wouldn't be stock JTM45 spec, and this is what I'm trying to archive

...minus grounding schemo ;)