Should I buy this JMP 2204?

tonegoals

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Hi - new member here, just after a bit of advice from some Marshall experts!

I am looking at buying a 1977 JMP 2204. The amp seems to be in great general condition and has recently been serviced. The seller has said the amp is all original "with the exception of pots, filter caps, preamp sockets and a couple of capacitors and resistors that had deteriorated due to age". The original valves have also been been replaced with tung sols.

I've attached a gut-shot of the amp, which appears to show quite a few different components to other images I have seen online for these amps. It seems that the mustard caps have been replaced?

I know virtually nothing when it comes to electronics and amp building, and this will be the first bit of vintage gear I buy. So my questions are:

1- have the modifications mentioned above reduced the value and collectability of the amp?
2- looking at the internals, does the amp seem in good general condition and have any other mods been made?
3- should I buy it and what's a good price?

Thanks for your help!
 

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betacisse

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those caps and filters and all go at some point, so now that theyre new you dont have to worry about them for a good while!

It looks nice and if it sounds good then go for it!

Cant say about the price, used market marshall prices have gone way up in recent years! I paid 1500 euros for a 2204 and 4x12 cab few years ago but now its hard to get just a head with that price!
 

LargeBoxSmallBox

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Those green caps are authentic Marshall caps, and they sound great! Mustard caps were on their way out at that point, and you find very few JMP 2204's with all mustards (I have one of them). Also, a 2204 with those caps is likely post-circuit change from the original flawed design, so that is a good thing.

The pots being changed out, well, you live with that, if it was necessary. Same with the tube socket. But it doesn't look like anything bad was done to it, from that photo. Some folks on here are a lot more knowledgeable than I am.

I'd like to see photos of the outside, and photos of the iron, but from just that one photo, I would snag that amp right now, if the outside is good, the iron is original, and the price is right. Given those things, that amp would likely be a keeper. That's my .02...
 

Trouble

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Looks pretty clean. Where you live may influence the price. But, around here under 2k is a fair deal, $1500 would be a great deal $2500 maybe more would be reasonable if the rest of the amp is in near mint condition.
 

V-man

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With that layout the #1 thing I would be wary of is date of manufacture. (see “letter date code on SN/how to date decode a Marshall”)

That absolutely appears to be (i wager “must be”) pre-‘78, possibly/likely pre-‘77. 2203s were *relatively* consistent amps. 2204s were not, in that the first few years (to mid-‘77) there was no cascade gain, making these a significant departure of what one would expect from a 2204 (sounds disappointing/shitty by compare).

Worse, the “mod“ from my cursory understanding is not a simple one-wire mod, hence likely not cheap, possibly not feasible. The one thing you may have going is the guy(s) before put in work/maintenance and may had enough understanding/willingness to have addressed this…”may.”

A simple but perhaps not 100% reliable trick is to bring 2 cables. After jamming each lead into the Hi and Lo jacks of the amp, you should not hear signal at the Hi jack. If you do hear a signal from the Hi (like it would happen in a non-cascaded JMP plexi), this is (likely) one of the problematic pre-cascades, or (possibly) malfunctioning somehow.
 

neikeel

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Yes it is
Quick way to tell is of there is 300k on cathode follower plate supply
This has a 'new' 100k which means it may have been converted but the V1 cathode components look original so may be just replaced part
The wiring around the jacks is typical 2203/4 cascaded type
 

tonegoals

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Thanks for replies everyone! The serial number is 07592J, so would suggest 77, and the seller says it was made in April 77 specifically. Transformers and choke are all drake originals and outside of the amp is in very good condition. I’m in the UK and I think these can go for a bit cheaper over here (I just missed out on a 2203 from the same year for £1200) but just wanted to check I wasn’t buying a dud!
 

AndyD

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What part of the world are you? The amp looks pretty decent. What speakers are in it?
 

neikeel

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The coupling caps are original and date the amp to early 77 (I had a JMP50 Model 1987 with them and it ripped!).
They work very well and I have had no issues with them, others have commented that they can be mechanically fragile if you throw the board around (why would you) and I would certainly leave them. From limited pics the work seems to have been done ok.
In summary I see replaced 1k screen resistors, added 1R bias resistors on output valve cathodes, three replaced preamp socket (Beltons with nyloc nuts) the cathode follower plate resistor, V1 plate resistors, PI plate resistors, input jacks, output jacks and redone soldering on the selectors, the grid resistor on V1 looks odd but maybe just the goop from Marshall's lead dress glue.
I would imagine form what was replaced someone was chasing some preamp noise and went the 'Fender' route (common to replace the plate resistors).
Personally I would want to play it first to make sure that the servicing work has made it 100% or have a return policy if the price is full,
 

XTRXTR

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That V1 grid is shielded and it may be hot shielded to the plate as I don't see a ground coming from it on the pot side - need a better picture there. This is nothing to worry over many amps have done that - its valid. I think it was well done especially if it was a non-cascaded 2204 that was converted properly to cascaded as it was meant to be. The shielded grid V1 crosses cathode at 90 degrees and the plate looks orthogonal to the the same cathode at approx 90 degrees. The other side looks good too.

Seems like a good deal with the Drakes. Verify it works of course.

Is there a back story as to why the 3 preamp tube sockets and pots were replaced?
 

tonegoals

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PLOT TWIST

The guy I was buying the 2203 from got back to me to say the other buyer pulled out, so I've jumped on that one instead. I was leaning towards a 50w model for the reduced power, but realistically I would have to attenuate either amp most of the time, and this 2203 is apparently completely original. For £1200 I think I've got a bit of a steal!
 

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jcm800gridlock

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My first Marshall was a ‘77 2204. I’ve chased that tone ever since I sold that amp to finance a honeymoon. Good move to buy this one.
 

AndyD

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PLOT TWIST

The guy I was buying the 2203 from got back to me to say the other buyer pulled out, so I've jumped on that one instead. I was leaning towards a 50w model for the reduced power, but realistically I would have to attenuate either amp most of the time, and this 2203 is apparently completely original. For £1200 I think I've got a bit of a steal!
I think you've done really well there. I had a 2103 from the same year full of Mustard caps like yours. The best example you can have, imo. They sound fantastic!
 

FleshOnGear

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PLOT TWIST

The guy I was buying the 2203 from got back to me to say the other buyer pulled out, so I've jumped on that one instead. I was leaning towards a 50w model for the reduced power, but realistically I would have to attenuate either amp most of the time, and this 2203 is apparently completely original. For £1200 I think I've got a bit of a steal!
Congrats on the deal! She’s a beauty!
 

Deftone

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PLOT TWIST

The guy I was buying the 2203 from got back to me to say the other buyer pulled out, so I've jumped on that one instead. I was leaning towards a 50w model for the reduced power, but realistically I would have to attenuate either amp most of the time, and this 2203 is apparently completely original. For £1200 I think I've got a bit of a steal!
Nice one. Helluva deal too. Congratulations.
 


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