Marshall JCM 800 Series 4140 4145 Club and Country and more Service Manual

[TomCarlos]

FYI post only....

One of the amps I have in my collection that I am selling (for a family estate sale) is the Marshall 4140 Club and Country. I went searching for a schematic and found the one floating out there - all fuzzy, distorted, hard to read, etc.

There is another post on MEF that has some info on the 4145 JCM800 Club and Country, 100W 4x10" combo.

I came across a Service Manual for the Marshall JCM 800 Series, including the 4140 4145. So I will post that here if anyone should stumble across this post and need it. Click on the link below to download.

This particular amp that I have will need tubes, pot cleaning, etc. I just don't have the time to invest in this one as my backlog is growing. I already have a buyer who will willing to take a risk on the amp (at a super discounted price of $400).

I guess Stevie Ray helped make this amp popular.

Anyway... click and download.

And my continued thanks for helping me when I need you all !!!

Tom







Marshall_JCM800_Series_Service_Manual.pdf

[g1]

What I like about that service manual is the spec sheets that give the power output rating at higher than usual distortion (10%).
90W for a '50W' amp.
That's probably more realistic about how they are played (especially with attenuators), so you get a better idea on why they can be hard on tubes, speakers, and OT's.
People generally don't play Fender amps like that.

[The Dude]

Cripes sake! Is there anything they didn't fuse?

[g1]

This particular amp that I have will need tubes, pot cleaning, etc. I just don't have the time to invest in this one as my backlog is growing. I already have a buyer who will willing to take a risk on the amp (at a super discounted price of $400).

I think you could sell that amp 'as is' for that price all day long (assuming it is basically functional). Especially if stock speakers.
If you are not committed to that buyer I would suggest more research on the value.

Cripes sake! Is there anything they didn't fuse?

That appears to be what is often referred to as the 'CSA fuse board' in a non-CSA amp. There's only 10 fuses in there that I know of.
Here's the only schem I've seen with all those fuses: https://drtube.com/schematics/marshall/78331-3.gif

[TomCarlos]

Yes, the amp was sold at $400. But this same guy also bought a Carvin X100B head and the Randall Switchmaster that I just fixed up. So in the end, a good deal for all and he went crazy over that Randall....!!!

I had four other offers, all at a mystical $300 number. It was as if it was a band of friends ganging up on me. So in the end, it went to a good home. This guy will put whatever it takes into having this amp running as it should be.

Next, I will turn my attention to a couple Yamaha amps - a T50C and T100C Yamaha/Soldano combo amps. There is a loud hum in each. But that will be a different thread if I have any issues.

[The Dude]

............That appears to be what is often referred to as the 'CSA fuse board' in a non-CSA amp. There's only 10 fuses in there that I know of.
Here's the only schem I've seen with all those fuses: https://drtube.com/schematics/marshall/78331-3.gif

You silly Canadians.

They should have just used one of these.

[g1]

You silly Canadians.

My favourite part about those (CSA version) was they had to omit the 16ohm setting; as it could develop more than some 'x' number of 'safe' voltage on a speaker cable's 1/4" plug. As if we like to hold on to them while someone plays it dimed. Well that took all the fun out of it and now we have to stick with peeing on electric fences.

[pdf64]

Fusing the bias supply seems either ill advised or a box ticking exercise.