MV50 endless service need

[Beeg]

I thought I had submitted this concern yesterday, but looks like I probably failed to hit submit.
I bought a used CJ MV50 amp about 18 years ago. Ever since buying it I’ve had frequent issues with the right channel dying. I haven’t touched it since it last happened 5 or so years ago. Bill Thallmann worked on it twice in my ownership, and each time it didn’t seem to be a significant dysfunction that he repaired. But all the same, after about a year or maybe two, the same dramatic pop would sound and the right channel would fail. I fed it new buss fuses like candy, I swopped out tubes, but to no avail it would happen with a regularity.
Any owners have this experience, or an educated guess why this had been happening? No local service seems to want to touch it. The excuse is I need to have a dedicated CJ expert because CJ is stingy with its schematics - but even when I was able to find a schematic ( from someone on Audio Asylum), the same vintage amp expert , declined because he possibly couldn’t parse the secret voodoo that Bill had upgraded it with, or some such sounding malarky
This thing weighs about 40 pounds and the bother of and cost of sending this tank to CJ or other non local service feels prohibitive any more. I have sunk about $1k or more on tubes, shipping and service in these 18 years….But I loved the amp.when it worked it was pure bliss.
I’d sell it, but who will buy it at a good price if it doesn’t function?

[AnotherJohnson]

Your CJ gear is very old. Bill T has now passed on.

It is a miracle that any of this old gear can be supported at all now 30+ years after the fact.

CJ would be happy to diagnose and service your stuff, but it’s not free. It’s a very small company, and they don’t typically have the resources to subsidize repairs on very old gear.

If you want to use the PV5 and MV50 because it is a low cost option, you’re going to be disappointed. It is probably cheaper to buy a new integrated amp from Denon, Sony, Marantz, Cambridge Audio, NAD, etc. new gear comes with a warranty.

As for selling the old gear, offer it as is to the highest bidder on eBay, or the best offer on Audiogon. There are people who like to fix stuff to flip it. These two units would be easy sales at $800 to $1000 each if they were working properly. Not working, I’m thinking maybe $300 each? YMMV

[Beeg]

Thank you. Good sound advice. I contacted CJ and their service person would handily fix with a free estimate. It won’t be cheap at 165 bucks per hour, plus actual repair and parts, plus shipping. I likely will sell as is locally likely. Repairs for my PV 5 will probably cost 900 dollars per his estimate and I’m sure as much for the MV50. Forget i

[admin]

FYI, we do have the schematic in our database here if you need another copy. I think it also has a parts list as well which is helpful.

It's always difficult to make the decision on repairing old gear which inherently does not have a very high resale value. I think it comes down to how much you love those units. If they have some special meaning beyond their capabilities, it may be worth to repair. But you can probably get something better for less money than the repair costs. This includes vintage CJ gear but newer than the MV50 and PV5.

[Beeg]

Thank you for your kind information. It is very helpful to me to find this helpful practical information in weighing cost vs distinctive merits of the two vintage CJ units I own.

[roberto]

Hola,
Any person or tech who knows vacuum tube's electronics can do a repair. You have two channels that are made with the same value parts. You have a working channel where you can measure the working voltages by comparison. Also, there is a simple design, using quality parts only too. You must replace them with the same value and quality. Many times, a resistor is the culprit on the small signal tubes. So, you can find a tech that could work on it. Tubes are simple vs SS.

[admin]

One positive here is that the MV50 circuit design is very simple. We even have a parts list in our database. The circuit board is also spacious compared to modern designs. It simply does not get easier than this. That of course doesn't mean that everybody is capable of working on the unit (or should).

[Tozco]

I would urge you not to give up on it. I too have had my CJ amp and preamp for a while, thirty years, and I have had a few problems with them over the years. I am a self taught tech and have been able to get them working each time. Sometimes it seemed hopeless and I felt they were dead weight, but with persistent effort, I always managed to get them going again. They are very simple to work on compared to most other pieces I've worked on. I'm very attached to mine, a prototype MV-45 and a PV-2. Either keep trying to find a tube amp guy or try it for yourself, just study up a little on tube amp repair.

[admin]

I too have been guilty with having emotional attachments to my gear. I kept a CJ DAC in the system far too long even when I had very good reason to be able to decode higher than 16b/44khz audio. I very reluctantly gave up my CJ Evolution 2000 when an incredible local deal opened up for my ART mono blocks. I think this simply reflects the "human" component of the hobby. Not sure if it's good or bad, most likely a bit of both.

But as I stated before, if there is an attachment to the gear, OP is lucky in that it doesn't get much more DIY serviceable than something like an MV50.

[abwilson]

Hello,

I have owned an MV50 since 1988, but it gets little use, maybe a few hours a month. I am using it with a pair of Quad 988 speakers. Looking to buy something newer, but used prices on cj equipment seem overly high to me. Have considered Audio Research, but may just switch to solid state considering the prices of tubes now. I had it recapped (Mundorfs) by Amplifier Surgery southwest of Chicago (Downers Grove, I think). I think they have a waiting list, my repairs were done about 10 years ago, no problems, I dropped off the amp at the gentleman's house and picked it up a few weeks later. Just an alternative, if you live in the area. https://www.amplifiersurgery.com (630) 452 - 2998

Good luck,

Alton

[admin]

Never heard of www.amplifiersurgery.com. Good to have another resource for repairs. It does appear they are running 29 weeks out for repairs currently. So that may be a factor for some.

[paulCJ]

Any conclusion with the MV-50? Any luck in finding used CJ amps for sale that could replace the MV-50?
Admin, I assume you still like your MV-55?

[admin]

Any conclusion with the MV-50? Any luck in finding used CJ amps for sale that could replace the MV-50?
Admin, I assume you still like your MV-55?

Yes. I have the MV-55 in my 2nd system which is paired with a PV-14L. A very nice combo. With upgrades I like to keep the units on par with each other to the best of my ability. For example, when I I was running a CJ PV-12L for preamp, I had the CJ Evolution 2000 as the amp. When I upgraded the amp to the CJ ART monoblocks, I upgraded the preamp to the ET7s2 in rather short order.

I've said before that the chain is only as strong as the weakest link. All these units are great. But they are great to different degrees. Of course our decisions are influenced by cost and opportunity. I think going from something like an MV-50 to an MV-55 would be a significant upgrade but still one that makes sense even you were not planning to upgrade other parts of the system just yet. You get a better sounding amp that is 10 years younger and is one of the "proven classics" in the CJ line. But I think it could hold its weight with something on the newer higher end as well. I believe you just purchased a GAT-S2. That certainly deserves a better amp than the MV-50 in my opinion. Whether the MV-55 qualifies for that is a good question. It's a very solid unit but the GAT-S2 is top of the line CJ and two decades younger.

[AnotherJohnson]

You mention the Levinson 5302 in another post.

Unless you are really into “euphonious” distortion, the 5302 will run rings around any of the MV amps. It punches way above its typical discounted or used price point.

If you want to actually fully exploit a GAT2 with a tube amp, you’re going to have to get into the ART series.

[Big Dog RJ]

Correct! That's why I said get ready for a whole lot more spend.
Anything below the ART series... the GATS2 is not the right choice in preamplification. Although, a GATS2 would still perform mighty fine within the LP or new Classic line but the ART series power amps is where the GATS2 truly belongs in.

The ART series 1 monoblocks, the ARTsa is a superb match then comes the ART150 and ART300's, that's even better! Anything above those, leading towards the ART27A and ART108A's, that's ART88 territory, top of the line. Even the GATS2 is surpassed here.

Either way, not to worry about it at this stage, just take your time.
As and when you ever get hold of any ART series amplifiers, then you'll realise the full potential of the GATS2. It's supreme!

That deserves a mighty WOOF!
RJ

[paulCJ]

If the GAT-S2 and the 5302 pair well together, that just might be what I am looking for.
Am hoping a newer CJ pre has a cleaner, non-syrupy signature but still wonderful (a better, cleaner wonderful) with female vocals and string instruments.