Marshall JCM800 Questions

midgod07

Active member
Hello all, I have a possible line on a minty 1984 JCM800 2204. It's supposedly been serviced every other year and has had new caps. No mods. What are the things I need to look for to make sure it's as valuable as asking price, retains value, and sounds the way a Marshall should? I'm a newb to the vintage Marshall game. I realize things need to be replaced, but are there parts that "should" be original? I need to know what questions to ask. Assume I'm an idiot when it comes to amp parts, because I am. ie, the "blue things in the back of the amp", etc. Thanks!
 
Thanks folks. Sorry for the rookie question. Awaiting pics from seller . . . have been told that caps and tubes have been replaced. That's all I know so far.
 
After listing a '81 2204 here for some time it would not move for $2500, a local trade for a 2203 came and I moved it for the amount above. If u list that 2204 and it is mint do it@$2200 plus shipping and it should go...
 
Thanks folks. Sorry for the rookie question. Awaiting pics from seller . . . have been told that caps and tubes have been replaced. That's all I know so far.
Depending on the condition of the original tubes/filter caps, you may want them if the seller still has them. Which is probably not the case; but vintage tubes if they are still usable will most times give you better tone than any new production. If the original LCR caps aren't leaking/bulging and were just changed "because they're old and need it!" which most techs will shout, I'd get those too and keep them. I'd even go so far as to put them back in.
But, that's me. I have a 72 Supertremolo that has its original Daly caps. They still get that amp to punch like no other I've ever played(including Wizards; Mesa Coliseum). In these old Marshalls, nothing in the amp technically 'needs' to be replaced unless the part isn't performing like it should. Like others said, original transformers are the most important things that need to be there for full vintage value. Non original OT; value drops big time. PT? Not as important as the OT but value does take a hit.
 
I'm no Marshall expert, but this is supposed to be an '84. I'm assuming the ink stamps on the trannies are the dates . . . if so I think I see '87 and '88 peeking out, which would mean trannies had been replaced?
 

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From memory the 2203 has more headroom so takes a bit more "pushing" to get "the" tone out of them but ultimately sound better and the 2204 is a bit more practical volume wise to get the tone
 
Can you get a pic of the board/ inside of the chassis? That would be a biggie for me as I’ve seen a lot of “stock” 800’s modded by absolute goons and later sold as stock. Also get a pic of the inspection tag. The choke looks stock but I’m not sure how they were dating them during that time so it may be an 87.
 
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Have the seller lower his camera so we can see the serial #. 1984 would have an S next to the number. Should be next to the speaker jacks; on the lower portion of the back panel.
 
Can you get a pic of the board/ inside of the chassis? That would be a biggie for me as I’ve seen a lot of “stock” 800’s modded by absolute goons and later sold as stock. Also get a pic of the inspection tag. The choke looks stock but I’m not sure how they were dating them during that time so it may be an 87.
It’s been a struggle to even get those pics. I don’t think the seller knows everything that’s been done but getting info is like pulling teeth. So I’m not sure if it’s an ‘87 that he thinks is an ‘84 or an ‘84 that’s been worked on. Do those look like original trannies?
 
It’s been a struggle to even get those pics. I don’t think the seller knows everything that’s been done but getting info is like pulling teeth. So I’m not sure if it’s an ‘87 that he thinks is an ‘84 or an ‘84 that’s been worked on. Do those look like original trannies?
As far as i can tell from the pics: Yes.
 
It’s been a struggle to even get those pics. I don’t think the seller knows everything that’s been done but getting info is like pulling teeth. So I’m not sure if it’s an ‘87 that he thinks is an ‘84 or an ‘84 that’s been worked on. Do those look like original trannies?
The Transformers look original to me. 1984 is a strange year as early ones have vertical inputs; later in the same year they switched to horizontal like yours. The good news is they still had the more desirable transformers in them; with the higher plate voltage. From what I've read they started to go lower voltage in 85/86.
 
Those look like the typical transformers and choke, but the 8 87 stamp is odd. I don't think people swap out these things all that often, so it's probably fine.

But I would not spend "premium" money on a Marshall if I could not first see good pictures of the circuit board and such. Those things were monkeyed with all the time. Usually any weird "mods" came just be put back to stock, but sometimes there are some real horror shows and either way, it would not be worth top dollar.

If it's not cheap and he won't show you pictures of the circuit board, just walk away IMHO.
 
Buy the amp.
If it's fucked,there are PLENTY of people here that will help you get it going.
But that's my opinion based on the time I've spent here.
And I know absolutely nothing about fixing amps. But I have an army of friends here that do.
 
Depending on the condition of the original tubes/filter caps, you may want them if the seller still has them. Which is probably not the case; but vintage tubes if they are still usable will most times give you better tone than any new production. If the original LCR caps aren't leaking/bulging and were just changed "because they're old and need it!" which most techs will shout, I'd get those too and keep them. I'd even go so far as to put them back in.
But, that's me. I have a 72 Supertremolo that has its original Daly caps. They still get that amp to punch like no other I've ever played(including Wizards; Mesa Coliseum). In these old Marshalls, nothing in the amp technically 'needs' to be replaced unless the part isn't performing like it should. Like others said, original transformers are the most important things that need to be there for full vintage value. Non original OT; value drops big time. PT? Not as important as the OT but value does take a hit.

Quit telling people to put shit caps prone to leaking with high ESR that will take out transformers if you care about OEM transformers so much. Just because the electrolytic insulation isn’t dried up and expanding doesn’t mean it can’t have an internal short or a leak at a seam due to expansion/contraction at the solder tabs. Caps 20 years old need replaced and are considered normal wear and tear items.
 
Quit telling people to put shit caps prone to leaking with high ESR that will take out transformers if you care about OEM transformers so much. Just because the electrolytic insulation isn’t dried up and expanding doesn’t mean it can’t have an internal short or a leak at a seam due to expansion/contraction at the solder tabs. Caps 20 years old need replaced and are considered normal wear and tear items.
WTF are you talking about??? Ok so change them because they're old. Ya ok. Whatever. Biggest bunch of fn bullshit from techs is "gotta change the filter caps". Bullshit. If it ain't broke. Get it? I've had more Marshalls than years you've been on this planet. Never had one vintage cap fail, ever. And the one time I did notice them leaking, I changed them. No problem.
If your so goddamn right on your bullshit about the caps, then why are my 1972 Daly caps running strong and have no signs of failure? The amp would flatten anything you have including your precious blanket over speakers Bogner. Why are the original caps running strong in my 1964 Fender? Because they're still good. That's how it works.
60 fn year old filter caps still running strong. No worries.
I don't give a rats ass on what degree you have or how adept you are a building an amp. "Gotta always change filter caps" is a fucking bullshit statement, period. Maybe on a newer POS 5150 or the like with shit caps, IE not LCR/Daly then maybe so...but on these vintage amps they can and will last 50, 60+ years.
Now you can go fuck off and play with your solder gun for a while.
 
WTF are you talking about??? Ok so change them because they're old. Ya ok. Whatever. Biggest bunch of fn bullshit from techs is "gotta change the filter caps". Bullshit. If it ain't broke. Get it? I've had more Marshalls than years you've been on this planet. Never had one vintage cap fail, ever. And the one time I did notice them leaking, I changed them. No problem.
If your so goddamn right on your bullshit about the caps, then why are my 1972 Daly caps running strong and have no signs of failure? The amp would flatten anything you have including your precious blanket over speakers Bogner. Why are the original caps running strong in my 1964 Fender? Because they're still good. That's how it works.
60 fn year old filter caps still running strong. No worries.
I don't give a rats ass on what degree you have or how adept you are a building an amp. "Gotta always change filter caps" is a fucking bullshit statement, period. Maybe on a newer POS 5150 or the like with shit caps, IE not LCR/Daly then maybe so...but on these vintage amps they can and will last 50, 60+ years.
Now you can go fuck off and play with your solder gun for a while.
And this gentlemen is why you don’t listen to non-professionals.

As someone with a masters in EE, your transformers will draw more current from caps that look electrically like resistors than capacitors and is the exact reason oem transformers normally let go.

Change them out and don’t be a dumbass. Or leave them - I get great discounts on fucked up originals who owners are too busy sniffing corks.
 
And this gentlemen is why you don’t listen to non-professionals.

As someone with a masters in EE, your transformers will draw more current from caps that look electrically like resistors than capacitors and is the exact reason oem transformers normally let go.

Change them out and don’t be a dumbass. Or leave them - I get great discounts on fucked up originals who owners are too busy sniffing corks.
Tell ya what, know-it-all, why don't you join over on the Marshall forum and ask your question. The only clowns who chime in and say "Always change those caps no matter what!!" are 'techs' like yourself. Builders like Larry and others value those old LCR and Daly caps; and will gladly buy them up by the box if possible. There's a couple British restorers of vintage Marshalls, who have boxes of Mustards/Eerie and Daly caps, that will agree and say the same thing...if they aren't bulging, leaking and the amp sounds strong like expected then they are just fine.
I'll bet you also 'recommend' ditching the tubes when you do a cap change...and gladly stash away a nice vintage set of power/pre tubes. Another nice 'tech' move.
 
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