71 JMP - screws for backplate

antichef

antichef

pornk rock
Just picked this up - it was on consignment:

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It was sold as a "1971 Marshall" - couldn't get any more info. Of course it's a JMP, and it looks to be 50 watts - it has three 12AX7s and two EL34s (and the tubes appear to be original - wow).

Anyway, I have the backplate, but all four screws are missing. Does anyone have an amp like this that they could pull a backplate screw from and maybe post a pic next to a ruler or something? I want to get replacements that are about the same size/threading.

The amp sounds *killer*, once your turn it past 6, btw (like God talking to Moses, as a friend of mine likes to say). I don't know whether it's "large box" or "small box" or anything like that - anyone know more? (edit: based on feverish googling, looks like large box)
 
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Fuuuuuuuuck me. Nice score, man! I have an '82 2204 but the backplates and screws are likely different. The blackplate on my head is a simple piece of sheet metal with holes on a 45 degree grid pattern. If this sounds like yours, I'll measure/photo them for you. They are the originals.
 
Thanks- I've got an '86 2204, and I think it's the same kind of backplate as yours - just mesh metal - I've still got three of the four original screws. I'm sure they're different on the JMP - the backplate is tolex covered wood, so the screws have to be long enough to get through to the underlying wood of the head.

But thanks man!

Long live the 2204! Yours must have the vertical inputs. Mine has horizontal, and supposedly the same circuit, except that shit is mounted to the board (like inputs, which is why they have to be horizontal) - about a year ago, I had volume dropouts, leading to complete failure, and a tech had to rework all the joints for the pots and the inputs, because they had cracked over time - I'm thinking this is why the vertical input ones are preferred (at least one reason :) ). Back in action now, though.
 
Holy fucking shit I'm jealous. It's rare that I'm envious of anyone else's gear, but I am of yours. You dirty bastard.

Where'd you find that thing? How much?
 
It was at Music go round on south 45 - used to belong to one of the guys at Lone Star Guitar. 1500 out the door (tax included, that is). Funny I went in there looking for some particular pedal because I've been trying to get more of a JMP sound out of my newer amp, and they didn't have the pedal, so I looked around, was about to leave, did a half hearted room scan, and saw it.
 
antichef said:
It was at Music go round on south 45 - used to belong to one of the guys at Lone Star Guitar. 1500 out the door (tax included, that is). Funny I went in there looking for some particular pedal because I've been trying to get more of a JMP sound out of my newer amp, and they didn't have the pedal, so I looked around, was about to leave, did a half hearted room scan, and saw it.
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Damn at a Music Go Round? I've never seen anything worth a shit at those places except for a few decent used cymbals. Cool score.
 
Seeker of Rock said:
It does. So between your two Marshall heads you're in amp heaven. Really impressive if that thing has the original tubes still in it. It looks very low mileage from the pic.
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Yeah - it's claimed to be all original - there's a hole in the backplate, and the story is that owner before last started a master volume mod, but then backed it out. The seller is a reputable guy, so it's easy to take the story at face value. Nevertheless, despite its quiet operation and thunderous sound, I'll take it in for a check-up. I also read that some amps were coming out of the factory that year with the standby circuit miswired such that mains voltage was slamming in right away - and when I turn it on without the volume all the way down (which I will no longer do), I don't get the fade-in that I'm used to, so this could be one of those - speculating - anyway, the symptom is that you blow the output transformer, so I definitely want to get a good feeling about it, even though it seems unlikely for a 41 year old amp to still be working with that problem.

And yeah - amp heaven :) except for the neighbors. They're in amp hell.
 
moresound said:
Many a purchase by myself has been in the same manner.
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Yup. I found my current Marshall head the same way. It was at the bottom of a pile of used stuff in a corner. I was walking by and saw the corner cap and a hint of white piping and my nuts tingled a little. I ran over, dug it out, plugged it in, and blammo. I was sold.
 
Greg_L said:
Yup. I found my current Marshall head the same way. It was at the bottom of a pile of used stuff in a corner. I was walking by and saw the corner cap and a hint of white piping and my nuts tingled a little. I ran over, dug it out, plugged it in, and blammo. I was sold.
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:laughings: This is when one knows that he has a wiener ..... I mean winner!
 
moresound said:
:laughings: This is when one knows that he has a wiener ..... I mean winner!
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Spider man has his spidey sense....I have my tingling nuts. They alert me to awesomeness.

So antichef, let's hear some clips of that beast. I looooove vintage Marshalls. Crank that thing and let's hear it! Hell, I might be able to hear it from my house. :D
 
shoot - I'm back to trial and error with recording this thing - I still can't get the bass or the hugeness, but here's something anyway:





I'm playing mostly octaves. I'm kind of into that right now.

These both have a fizziness that I'm not hearing in the room - after going through a bunch of mics (including my favorite ribbon, which saturated and clipped like a dying bunny's big watery eyes), I wound up with a MD-421, and didn't have time to try too many placements. Anyway.
 
Greg_L said:
DO NOT take it to Evans.
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thx - I actually have two amp guys (both inside the loop) that I'm really happy with. If you ever need details PM me - or I guess I can just post one here: Tubemodules.com Tube Amp Repair Michael Fratus - he reanimated my dead JCM-800 and it sounds a lot better than it ever did. He also built me an awesome bespoke class A power amp. The other one is an H-Town standard, who was rumored to be retired, but is apparently still taking jobs - selfishly, I don't wanna post b/c he's busy enough :) - PM me if ever needed.
 
Greg_L said:
Yup. I found my current Marshall head the same way. It was at the bottom of a pile of used stuff in a corner. I was walking by and saw the corner cap and a hint of white piping and my nuts tingled a little. I ran over, dug it out, plugged it in, and blammo. I was sold.
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Lol @ nuts - pretty much the same for me
 
antichef said:
shoot - I'm back to trial and error with recording this thing - I still can't get the bass or the hugeness, but here's something anyway:





I'm playing mostly octaves. I'm kind of into that right now.

These both have a fizziness that I'm not hearing in the room - after going through a bunch of mics (including my favorite ribbon, which saturated and clipped like a dying bunny's big watery eyes), I wound up with a MD-421, and didn't have time to try too many placements. Anyway.
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Cool I'll give it a listen later. Looking forward to it.
 
antichef said:
shoot - I'm back to trial and error with recording this thing - I still can't get the bass or the hugeness, but here's something anyway:





I'm playing mostly octaves. I'm kind of into that right now.

These both have a fizziness that I'm not hearing in the room - after going through a bunch of mics (including my favorite ribbon, which saturated and clipped like a dying bunny's big watery eyes), I wound up with a MD-421, and didn't have time to try too many placements. Anyway.
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Did you try jumping the 2 channels together and blending them?
 
ocnor said:
Did you try jumping the 2 channels together and blending them?
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Yeah, that's what it sounds like it needs to me. I like the rawness, but it's pretty bright. Might be mic placement? Jumping the channels is pretty standard with the 4-holers.
 
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