Originality and the Value of Vintage JMPs

[Dean Deese]

I just bought a 1977 JMP 2203 off Reverb a couple of weeks ago and it arrived DOA. Just had to evacuate do to Helene and went past my 7 day protection window. The seller knows this and told me I was SOL (can’t wait to leave feedback ()…
So, I’m dragging it onto the local amp tech to repair. My worst fear is the OT. I paid like $2700 for this head. What would “new” iron do to the value of my boat anchor? Boy, should’ve gotten a Friedman or Suhr, etc.

Thanks everyone, long time researcher, but not many posts as I’ve been out of the game for a long time and want to get back to playing and gigging again. Dean

 

[Matthews Guitars]

It's not an ultra rare ultra collectible amp. A replaced power transformer will barely affect its value. By maybe 100 or 200 bucks, that's all. A replaced output transformer, about the same. Everything else is small parts worth just dollars or cents each.

If either transformer needs to be replaced, stick with a quality replacement like a Heyboer or Hammond, or Pacific or maybe Mercury Magnetics, and make SURE the tech knows to transfer the brace brackets off the old transformer to the new one! And don't drill holes in
the chassis to make it fit! That is never needed, if the replacement transformer is appropriate for the amp.

But I think that the most likely cause of no sound when all the voltages are there and correct is that impedance selector on the rear panel. If it's bad or the plug is missing on the older models that had a removable plug, you get no sound.

 

[Joethebh]

I just bought a 1977 JMP 2203 off Reverb a couple of weeks ago and it arrived DOA. Just had to evacuate do to Helene and went past my 7 day protection window. The seller knows this and told me I was SOL (can’t wait to leave feedback ()…
So, I’m dragging it onto the local amp tech to repair. My worst fear is the OT. I paid like $2700 for this head. What would “new” iron do to the value of my boat anchor? Boy, should’ve gotten a Friedman or Suhr, etc.

Thanks everyone, long time researcher, but not many posts as I’ve been out of the game for a long time and want to get back to playing and gigging again. DeanView attachment 158925View attachment 158922View attachment 158923View attachment 158924

Did you happen to pay using a credit card? File a claim/dispute with your bank. Unless it ends up being a simple fix and you want to keep the amp…

 

[fitz]

So, I’m dragging it onto the local amp tech to repair. My worst fear is the OT. I paid like $2700 for this head. What would “new” iron do to the value of my boat anchor?

Find out what's wrong before you start guessing what the future value might be.
Might just be something simple, and some routine maintenance on an amp that age is probably a good idea anyway.

 

[Beryllium-9]

Reverb should have your back. If it was me I would file a claim with them claiming it doesn't work. Let them fuck with the seller..

 

[V-man]

It's not an ultra rare ultra collectible amp. A replaced power transformer will barely affect its value. By maybe 100 or 200 bucks, that's all. A replaced output transformer, about the same. Everything else is small parts worth just dollars or cents each.

It’s not that I can’t read this and spot truth within it, but this is easily misleading however unintentional.

The JMP is certainly not “ultra” rare. It was quite plentiful… which fuels global demand finding how many players paved their destiny with one. There are also no more JMPs produced (certainly not as they were) and unfucked originals are becoming rare, if they are not already.

The JMP is not “ultra collectible” (?) that hinges completely on what “ultra” is supposed to mean. A Dumble, or a Trainwreck, etc may be so rare that it is on the top of a collector’s list. But without question, any collector from obsessed hobbyist to engrossed archivist ALL demand a JMP (MV and NMV alike).

As for the $100-200 difference, absolutely not. There certainly can be instances where an amp of a certain condition/integrity may not take major hit. Other circumstances like the “premium” market (where this one is now disqualified from consideration), the difference is meaningful. The OT the heart and voice of the amp. The best damage control IMO is to find an era-appropriate replacement OT.

 

[dtier]

I hope you have a good tech. How this goes can largely depend on him. That is a beautiful example of a great amp. People here can help you through the repair experience. Have the tech contact you with a diagnosis and repair estimate before he starts repairing it. Can you better describe the DOA condition?

 

[Purgasound]

I think you're jumping to conclusions a little too fast. I can count on one hand how many bad transformers I've had to replace in the last decade. They don't go bad like people assume they do. It takes a fairly large fault to bring them down and a lot of them are misdiagnosed or replaced without ever properly testing the transformer. You can read every post in this forum and every other where someone says their transformer is bad and we'll ask if they put any voltage through it and tested the secondaries. The person will do everything in the world except put a few volts through the primary and measure the secondary. Blows my mind....

Anyhoo, let's move on to my other unpopular opinion. Vintage amplifiers have an associated cost of ownership. It's just like buying 46 year old car. Sure it might run but you can't expect to get it home and it would never require service. The vintage amplifiers out there for sale aren't owned by technicians. They're typically not maintained well, if at all and the owners will just run them as they are with failing capacitors, crackling pots and worn out tubes thinking that's just how an old amp sounds... Well, I suppose what I mean to say is, this is what you sign up for when picking up a 46 year old amplifier with original electrolytic capacitors. It's not a death knell. The amp can be up and running again in an hour for around $75 in parts plus a bench fee. Maybe new tubes too but we don't know. If someone expects the product they buy to be flawless then I suggest purchasing a new product with a warranty. I get it, we expect the things we buy to work. This thing has 46 year old electrolytic capacitors except for one in the bias supply that looks like it was replaced before dial up internet was a concept.

Last month I drove 3 hours south to pickup a '74 Superlead. The filter caps were already swapped so I thought that was a good selling point. I turned it on and immediately noticed a red plating tube. The guy who sold it to me was honest, said a tech went through it. Sure, well, they didn't catch something fairly obvious. Not a big deal and the guy sent me back some money for new tubes which I didn't ask for. I just let him know to bust his tech's balls a little bit. That stuff happens though. I've had a brand new tube fail on my bench when a client was trying his amp out before taking it home. So the amp needed some work and for someone without an amp shop I can see how it would be frustrating.

Just this week I bought another Superlead. This one from '86 and also had nice new F&T's in there. It was delivered through the mail and we'll packed. I check over all the tubes and everything looked fine. Turned it on and played a few chords, sounded normal, then I cranked the volume and POW it spit out an HT fuse. Output tube popped and shorted. It happens. It could have been anything.

Sorry, I like to chit chat about this stuff. Don't feel taken. Maybe the seller knew, maybe they didn't. The ones in tip top shape don't get sold, they get kept!

I'll give you one more stupid anecdote. I met a guy an hour north to pickup a nice Special Edition '86 2205 with the green tolex and small check grill cloth. The price was stupid good so I agreed to go meet them. We met in a parking lot and as I hand him the cash he says "yeah everything works perfectly and there's nothing wrong with it". I laughed in his face and said "ok buddy whatever you say!". I wasn't rude about it, just honest that I didn't believe him and it didn't matter anyway. From its age alone I knew it would need some kind of service. Went home turned it on and as it warmed up it starts to squeal louder and louder even with nothing plugged in. I just laughed and shut 'er down. That's just the way she goes, bud.

If a Superlead is used frequently at full volume it will roast the two filter caps closest to V4 and V5. Those two tubes draw almost double the current as V6 and V7 when the output starts clipping and they get incredibly hot. The excessive heat significantly shortens the lifespan of those parts. Back to the car reference, heat kills transmissions faster than wear and tear.

Hope you get it sorted out without too much trouble. Your transformers are fine. Cheers

 

[Purgasound]

Last but not least... Yes they are collectors amps at this point. Kids are not buying early and mid 70's JMP's to gig with. Only us old dudes with disposable income are buying them. It's a want, not a need so as much as we want to think of these things as tools they are predominately luxury items. I need one amplifier to gig and maybe a backup. Every other amp I have is because I think they're cool. Unmolested amplifiers are becoming increasingly rarer by the day. There's still guys out there permanently modifying pristine 70's and 80's amps and screwing their name badge right on the front. I did my fair share back when we JMP's and 800's were cheap and plentiful.

If you have one with original passive components and iron it needs to stay that way. There are plenty of butchered amps out there that can be updated for use as a work horse or modded. I restore a lot of these and it's tough to find NOS components at a decent price for a period correct restoration. I don't consider anything electrolytic to be sacred whatsoever. They have a finite lifespan and need to be replaced. Just like the worn frets on a '58 Les Paul. As my luthier says "Do you want to play it or do you want it to be original because you can't have both". Most of the board components are fine. Those mustard caps can leak DC when they get worn but those would cause audio issues and not a power issue like you're having. That one is in great condition. Keep it original aside from the electrolytic and you've got a great amplifier for the collection.

 

[Deftone]

Dumb question, may have already been asked but...did you check the fuses?

FWIW I picked up a JCM900 MKIII a while ago...barely made any noise. I just cleaned the jacks, tube sockets and pots with DeOxit and now it works perfect and sounds killer.

Boy, should’ve gotten a Friedman or Suhr, etc.

I just bought a Friedman...it's amazing. I love it. Am I gonna sell my '79 JMP 2204? Hell fucking no. That amp is the last one I would sell. I think Dave Friedman would tell you same thing.

Congrats on the new amp. Hope it works out.