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screaminglucy 10th June 2005 06:39 AM

marshall avt50h schematic?
the reverb box came loose inside my amp and the screws shorted it out...anyways, i'm trying to fix it and it'd be a lot easier if i could get a hold of the schematic...
can anybody help?

Enzo 11th June 2005 05:26 AM

I think I just sent you the drawings in response to your AMpage post.

screaminglucy 11th June 2005 04:03 PM

oh yay! thank you soooo much!

Dev 24th June 2005 01:21 PM

Hello! I'm new to these forums, but I got here via Google, because for a while I am searching for schematics of Marshall AVT amps. I'm mainly very interested in how they designed the preamp with the 12AX7-valve. I was wondering if you would send me the schematic mentioned in this thread (or any other AVT).

Greetings from the Netherlands,
Mark de Ruiter

Enzo 24th June 2005 11:44 PM

Dev, send me an email with "AVT50 schematic" in the subject line, and ask for it. My email address is described as follows to avoid spam.

tmenzo "at" msn "dot" com

buckeyesuave 2nd September 2006 05:41 AM

Could someone PLEASE send me the Schematic to the Marshall AVT50H


Albertb 2nd September 2006 05:34 PM

Don't know if you have been here yet but you could try these sites, they might help as they have an astounding set of schematics for everything under the sun:

You may not find the actual schematic for your own amp as it is current, they tend to prefer the older valve models, (as most of us do ;) ), but I am betting if you are flexible in your thinking you will be able to get somewhere with what is there on the older babies.

The reverb section in your preamp is no doubt one which is shared by a number of models past and present. While not exactly the same in all cases you will probably find one where things are pretty much similar to your own.

If you can post a few of the current symptoms, (burnt components, strange noises, silence?), assuming you have the reverb unit back in place and hooked up correctly again of course, someone may be able to advise. If you chased through the section around the reverb connections on the PCB and posted a pic of the schematic you find it would be even easier to help. :D

Albertb 2nd September 2006 05:48 PM

On the Dr Tube site there are some of the Valvestate amps with their reverb sections. These will give you a first idea of how things may be done.

or as one particular example you will find there:

which is one standard type circuit block to drive the reverb.

If it is just the reverb section at fault, all that may be necessary could be to renew any semiconductors around the unit. These need not be exact replacements. Despite "modern thinking", (read "common knowledge", ie there is no proof of it but we just "know" it to be the case), there will be very little change in sound by replacing with a close equivalent, as long as the pinout is a match too of course. Guitar amps played with a degree (?) of distortion would show more change of tone by using a different plectrum than by a swap to a similar IC or transistor!

Enzo 8th September 2006 01:47 AM

I sent it to him, I will assume he received it.

tkelly4585 16th October 2006 09:55 PM

hi, is there anyway one of you guys could email me this schematic. or at least tell me what the value of resistor R58 is?
my email is tkelly4585 at


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