JC-80 bad transformer and where to get one

[DrGonz78]

well to be fair he said that he would install a new trans for no extra charge. That is if I found and bought one, he can't find one, which is impossible so far without forking over a mint for a custom wound one. Totally not sure what to do...

Just have to say that there are some great techs on this site that would not replace that transformer by the symptoms described for this amp. So go spend more money on a transformer and he installs to only find out the problem is still occurring. What then? I go by the policy that if I can't fix something then I won't charge you for my services. I don't expect every person to do the same, however they would not charge $150 for an inspection. By the way I told you what to do already... Measure voltages on the mains power coming into the power transformer and the secondary taps coming out. At this point I think you need a second opinion on that much to start.

[52 Bill]

I don't know what size the original transformer is, but there is a guy on eBay selling NOS Musicman transformers for $15.00. If you really trust your tech and want to go that route have him look at the specs for that transformer and see if he thinks that it will work.

You have been advised here by a number of us that we don't believe that the transformer is faulty, but that is just our opinion based upon the details that you have posted here. There may be more details that you are not aware of that may change our opinions. But my personal opinion is that resoldering boards will never change how much voltage a transformer will output and is at best a shotgun approach to fixing something that one can't figure out.

It's your amp and you can do what you wish with it, but as Dr.Gonz stated, don't do anything that you don't feel qualified to do as there are dangers involved in working on these things.

[J M Fahey]

What did the tech charge you $150 for?

What does the repair bill say?

Besides him, who can ask whatever he likes for whatever he thinks fit, I can ask $150 for a hamburger if I wish (slim chance of selling any), why did you pay $150 for a NON solved problem?
I don't get it.

You tell me , say, $60 for a bench charge ... ok, you are forking money in exchange of *something* , meaning wasting time assembling and dissassembling, doing some tests to see what seems to be the problem, etc.
Fine, it's the nature of the job so far.
Diagnostic takes time and effort.

But $150, amp NOT repaired and to boot an iffy (being polite) diagnostic?

I don't understand why you paid him that much.

As of the surplus Musicman transformers , doubt one meant to feed 650/700V DC to a couple tubes can have much use in a fully SS amplifier which runs on about +/-40V rails.

That, IF the transformer is bad, which so far I doubt.

[Leo_Gnardo]

I go by the policy that if I can't fix something then I won't charge you for my services. I don't expect every person to do the same, however they would not charge $150 for an inspection.

Same here, and even a pro shop like Triple S in NJ charges only $45 for a look-at fee.

Some of the worst advice on MI gear I've ever seen comes from "professional electricians." One example - nice old Fender amp came in smokin' with a 30 amp fuse, should be 3. "My uncle the electrician says it's OK, doesn't matter what the fuse value is." Not the sort of guy I want wiring up my house, or anything for that matter.

Sorry to see this amp has turned into the dog's breakfast. Hope you can rescue it. Testing that PT without the rest of the amp attached would be a start. The light-bulb limiter will let you know, it's time to do that. Last week.

[52 Bill]

As of the surplus Musicman transformers , doubt one meant to feed 650/700V DC to a couple tubes can have much use in a fully SS amplifier which runs on about +/-40V rails.

Juan: sorry that you think so little of my opinion that I would suggest such a thing. The transformer that I suggested is for a solid state bass amplifier that I think has a 76 vct secondary.

[art_lessing]

I haven't paid him yet but I owe 150. and of course he still has my amp. $75/hr that includes, re-soldering the board, cleaning all the pots, diagnosis, and research into finding a proper speaker which I paid 130 and am itching to install , Weber Cal 15". BUt I am feeling a bit stupid now. Anybody know of anyone who will second an opinion up near Sacramento. Skip wont touch it.

[nickb]

I haven't paid him yet but I owe 150. and of course he still has my amp. $75/hr that includes, re-soldering the board, cleaning all the pots, diagnosis, and research into finding a proper speaker which I paid 130 and am itching to install , Weber Cal 15". BUt I am feeling a bit stupid now. Anybody know of anyone who will second an opinion up near Sacramento. Skip wont touch it.

Well, at the very least he should subtract out the time for the pointless re-soldering and the useless diagnosis. I don't think you did anything stupid - you went to a 'professional'.

[J M Fahey]

Well, at the very least he should subtract out the time for the pointless re-soldering and the useless diagnosis. I don't think you did anything stupid - you went to a 'professional'.

Useless fumbling around (he actually didn't repair it nor provide accurate diagnostics) does not count as "billable time" .
Don't know Law or customs there but you should be able to go there, maybe with a tech (or a 225 pound Football team captain) and get it back, as is.
Unless he proves on the spot, and to tour entire satisfaction, that the amp is working properly or at least appreciably better than when you left it.
If he refuses, maybe you could start a complaint at BBB, small cases court (is it so?) or whatever applies.
You are definitely NOT happy with his work so far, and he can't hold your amp hostage.
Of course, once you start talking angry, take that amp out of his hands at once, or he may randomly short the boards with the amp on, ruining it for good.
Even if the complaint filed leads nowhere, it'll be a black mark on him.
And being an incompetent guy, soon he'll have more.
Oh well, best wishes.

[J M Fahey]

Juan: sorry that you think so little of my opinion that I would suggest such a thing. The transformer that I suggested is for a solid state bass amplifier that I think has a 76 vct secondary.

Dear 52 bill, as amply stated by me many times, I hold you in the highest respect, including your experience and Tech advice.

I don't doubt, at all, what you know, but this is a very popular Forum, read by the Millions (ok, a few thousand) , and for the average reader the first image that instantly comes to mind, specially for the un initiated, when hearing the words "MusicMan Amplifier" is that of a hybrid very high voltage tube amp, and almost never an SS amp (ok, say, they might imagine it 1% of the time, and always as a second choice)
I think that your comment , which is not wrong, at all, should have been qualified to clear the (quite) possible doubt.

Something like "you can get some full SS Music Man transformers, guess they are 76V CT or thereabouts, they might work in the JC80, for about $15 , at xxxxxxxx.com"

FWIW I browsed a couple famous sites, the first ones suggested by Mr Google, and found:

Mercury Magnetics only list the HV/Hybrid types; not the slightest mention of the full SS type: Mercury Magnetics - MusicMan Amp transformers

Beyond Eleven the same: Music Man Amplifier Transformers - Beyond Eleven

Tube Amp Doctor the same: Mains Transf. for Music Man - Mains transformers Tubeampdoctor Store

Mojotone too: Music Man Power Transformers

and only in this page, at the bottom, they list the MM1600 ones, which I think are the ones you are referring to:
Power Music Man Transformers

Even at their prices, they are a nice option.
For $15, they are a steal

Sorry if any comment did sound out of place , no mean intention implied whatsoever.

[Enzo]

I have to say, when I read Music Man, the only thing that came to mind was the old Hybrid tube guitar amps.

[g1]

No disrespect intended to anyone, but when I saw $15, I thought "well, can't be for a tube amp then, they'd all be gone".

[J M Fahey]

Well, I thought the HV/Tube one but at the same time: where's the catch?
As in: all are "pulls" with way too short wire stumps or "87V 43 Hz primaries for use in Vuanatu Island only" or "stood in a flooded basement for 23 years" or ......

The *least* I would have imagined is that they are killer very high quality original OEM ones, straight from the former Music Man owner estate (R.I.P.) .

In fact if I were in USA I'd buy all of them, in bulk, no matter how many they have ... at a unit price of , say, $10 or so ... o.b.o.
Even at $15 each, that's about the raw iron laminations cost, in bulk.

[52 Bill]

Those transformers have been on eBay for a few years now, I bought a few just to have on hand.

[J M Fahey]

Good, they are almost "universal" for all 100/120W 4 ohms SS amps out there, from Valvestate to JC120 , go figure.
Probably G series Yamahas too.

In fact they are slightly hot, being +/- 45V rails so they might be too much of a good thing for quite a few; if they gave +/- 40V they would be truly universal, from old Kustom and Acoustic amps until today.

A problem might be that being overdesigned, big and heavy, they might not fit in some chassis, definitely not inside a GK one.

Pity they are only being advertised as "MM 1600 replacements" which are not exactly all over the place,, so they won't show up in most generic searchs.

I shudder thinking at how much MM must have payed for them , in inflation adjusted U$.

[art_lessing]

so confused now.... So say it is the trans..would one of those 15$ ones work..for my jc-80/60?.It might be worth the 15 bucks to eliminate thAt variable