Repair or mod CJ PV-12?

The transformer on my Conrad Johnson PV-12 bit the dust. I'm debating whether or not to send it to CJ for repair, or off to get mods and a new transformer. If the mods included a transformer upgrade, that would be a fantastic choice.

Some people here have had good luck with mods, could they provide who did them; from what I've heard they got fantastic results.

Any help you can provide will be greatly appreciated.
I picked up a PV9a recently for a quite reasonable cost and after much research and several phone calls decided to send it to Bill Thalmann of Sound Technologies in Virginia. He was the number 3 guy, technical director at CJ from their inception in the late 70's until he left around 2000.

I also called CJ. They are not as flexible about their modifications as Bill who is also a really nice guy. CJ is also considerably more expensive and I don't feel the young guy I spoke with has the knowledge or feel for these vintage designs as someone who has been around as long as Bill. Bob Backert in PA might also be someone to consider. I'll let you know Orpheus when I get the unit back as to the results, probably a few weeks. I would call CJ, Bill and Bob and find out your options before proceeding with anything.
It really depends what you want to do with the unit and if you are wanting to save money. For a tech that is familiar with tube gear,replacing the transformer is not very difficult. Replacing the transformer with a different will possible require new holes to mount the transformer. The schematic for your unit is available on line.

As far as upgrading the unit, the only thing I would replace is the capacitors and resistors in the signal path. If you look at the schematic I could easily point those out to you.

Changing parts with change the sound signature of the piece of gear and will not help the resale. If your going to keep it, I would recommend just swapping out the transformer and if desired, changing a few capacitors and resistors in the phono stage and a and couple more in the line stage.

You can of course spend a extra money and have someone that's experienced with the unit do the mods for you.
All good points Detredwings, I agree. It is why I decided to go with Bill who completely understands my goals and is going along the lines you described along with a few other things that should enhance performance in the areas I felt lacking without changing the character of the design.

Tubegroover and Detredwings, thanks for the invaluable advice; I would replace the transformer my self if I could find one. CJ won't sell one, and I don't know where else to go.

Since the mod people can probably get a transformer, that could be included with the mod. CJ was not specific enough for me; while their minimum for inspecting the unit wasn't bad, there was no guarantee in regard to repair. There have been complaints (not against CJ) about no follow through after submitting up front money. New scams seem to be contagious and they come in waves.

I'll contact Bill Thalman in Virginia, and we'll keep each other posted on progress; thanks a lot.
There is a really good possibility that something else caused the transformer to go bad. I've heard of PS problems with those units. Anyway, good luck and let us know.
If you are saying they won't sell you a replacement part for a product they make that's unforgivable. That forces you to ship it to them and back plus get ripped off for labor prices.

They can go ahead and gouge on the part price. But replacing a transformer is simpler than most any repair. Assume you are a technician yourself. And you need to send it off?

It's no wonder hardly any dealers sell CJ. I wouldn't give them another dime more than you have to. And upgrading it means you will never get your money back. High end audio manufacturers are making cash grabs anymore.

While it's very unusual for a transformer to go bad it happened, one of the windings went open. This was very easy to confirm with an ohm meter. Replacing the transformer would be a piece of cake, especially since I left the color coded wires attached and dangling off their terminations.

After I direct CJ to this site, and they see what you guys think about them not selling me a transformer, we'll see if they have a change of heart.

Thanks for your support.
Some good suggestions above. I would also give George Kaye (of NYAL fame) a call. He did some repair/mods of some NYAL and Counterpoint pieces I used to have and he did a very fine job. As an interesting aside he is a fine (and active) jazz bassist; very interesting guy. Good luck.

Detredwings, you brought up a very valid point, the "CJ glow" as we called it, is special, and does not exist on current models; they went to that sterile sound the reviewers decided was best. As we know, trombones sound "trombonier" and saxes sound "saxier" with these older CJ units; they seem to be especially voiced for jazz. While mods might give a better sound stage, there is the possibility of losing the "CJ glow".

I always come out ahead when I come to this forum for advice, while mods are a fantastic bargain in most cases, and could be in this case as well if you're not tuned to the elusive "CJ glow" that seems to be special for jazz.

Maybe after CJ see's this forum, they'll realize it's to their advantage to sell me the transformer.

Frogman, it's good to hear from you! I found George on "you tube", and he's pretty good on bass for a guy who builds amplifiers.

Thanks for your input.
FWIW, when I used to use c-j gear, I found c-j very good to do business with regard to repairs and maintenance.
I am amazed at how often this so-called "Audiophile Grade" stuff fails. And Audiophiles, being gluttons for punishment, always come back for more.

Cut your losses and Just drop that useless thing off at Goodwill, and get you a Marantz Integrated or Harman Kardon Receiver. And don't forget Emotiva!! Trane, Miles and his Mama, will still sound just as good.

One Frenchman's Opinion.


Rok, it's good to hear from you. Once we've been to New York, they can no longer keep us down on the farm.

"Harmon Kardon", the high end of mid fi, right there at the top of "Stereo Review's" list. "Receivers"? Do they still make those?

Do you have anymore Sage advice for me? Since I haven't heard from you in awhile, I'm not going to tell you what I did with your last sage advice; anyway, it's still good to hear from you even if I have to tolerate a little "Rokism"; that's a category for anything that has no category, I say that falls under "Rokism".
With all due respect, I think some of you guys are being unfair to CJ. First of all, there is a reason that the company has been around as long as they have been; they make good sounding gear and they have a reputation for good customer service. Orpheus10, by your own admission their estimate fee (for an out of warranty item) is "not bad"; imo, that alone should tell you something. The bone of contention here seems to be that they won't simply sell the transformer; not that they won't repair the unit. They way I see it, it makes complete sense that they would not want to simply sell the part and let an unauthorized individual do the repair. They want to make sure that their product is repaired properly and that their reputation is protected. Makes sense to me and to impugn their reputation over something like this is not reasonable. You have a piece that you like and makes music for you, you don't like the sound of the more modern stuff, prices for newer gear keep going up, and there is a possibility that there is something else wrong with the unit. Why not send it to those who understand the circuit better than anyone else and who have the most interest in knowing that it is repaired properly?
Orpheus with all due respect to Rok2id what he probably MEANT was the HK Citation II amp and maybe several of the highly prized Marantz of ancient lore that are still highly sought after. Legends never die but they can take on a new face totally unrelated to their heritage.

I agree with you Frogman. On the other hand I don't think they would have issues selling a transformer to a an established repair shop or technician such as Bill Thalmann or Bob Backert. I don't know what their current policies are now regarding that but from what I have read and heard from others the previous repair/mod tech at CJ, Ed was most accommodating.

Frogman, no one has impugned CJ's reputation for refusing to sell me a transformer, we simply find it unreasonable.

I am a technician whose bad back is acting up, and to pack this unit and take it to the post office would be a hardship at the moment.

Detredwings expressed my position very well; replacing the transformer is easier than changing a tire for a technician; as a matter of fact, since I left the color coded wires dangling from their terminations, you could replace this transformer if you can solder.

In regard to the possibility of other problems, I isolated and confirmed the problem with my ohm meter. This case at the moment is in our court, and you have represented CJ with dignity, plus you've brought up valid points I don't disagree with; however, if CJ hears my point of view, as opposed to blindly adhering to policy, they will sell me the transformer.

Tubegroover, I also own a PV-10A and I have sent it in for mods and upgrade, plus bought sets of tubes. This is the first time me and CJ have conflicted; while it's good for a company to have a policy, I don't think they should blindly adhere to it in all cases.

In regard to Rok, I doubt very seriously if he's taking his own prescription and buying any of them "rustbuckets".
Any item with the CJ name, or any other name, on the face plate, reflects on that company. Why would they trust the skills of anyone that requests a repair part. Because once you screw it up, it's still a CJ pre-amp. Esp considering you may then sell it to someone else. Good way to lose your reputation.

The safest bet is to stick with the so-called lo-fi stuff. It never breaks.

Of course, there is always the chance it ain't the transformer, or at least, not only the transformer. :) Your USAF skills notwithsdtanding.

BTW, recently got the Oppo 103. The only disc player you will ever need. Watched 'GRAVITY' last night. The best special effects ever!


Detredwings, all the people who can not hold a soldering iron or read a schematic think everyone else is so afflicted, consequently we have to overlook and at the same time understand the basis for their inability to comprehend what we have presented.

big fan of CJ gear here, keep us posted about your decision on this piece. I will be interested if you allow CJ to do the repair or send it to Bill Thallman or another modder.

Happy Listening!
What is you lived in Alaska or Hawaii and we were talking about a 75 lb amp? It's out of warranty. Any repair station should be able to call and buy a part. Most parts can simply be bought from part suppliers. Transformers usually not. So because that part failed now you get screwed?

That my friend is what is wrong in high end audio. There is not ONE valid reason they can give for their behavior.
The ONLY person to contact is Bill Thalmann at Music Technology in Virginia. He was the chief engineer at conrad-johnson for years and is the foremost authority on repair and mods of their gear. Best of luck!!
Hi Orpheus

Don't know the current status of your transformer dilemma and your decision on what to do. To followup I recently received my upgraded PV9 from Bill Thalmann. No fears with having him do the work and that I can say without reservation. The things I like about the PV9 are retained with just more of everything that I was hoping to achieve, clarity, detail but most notably improved natural and true timbre of instruments and voice all the while retaining that magical CJ warmth and "just sounds right" quality. The improvement at the frequency extremes, particularly the upper frequency extension and air is beyond what I expected and a huge improvement and really comes through on soprano and choral without the edginess I often hear or on the other hand a roll-off that can detract from the performance. I am most pleased with Bill's work and craftsmanship.

Tubegroover, I'm glad what you like best about your PV-9 was retained; for us that's a just right sound, we don't care about no stinking neutral.

I just got off the phone inquiring about the PV-12, and was told whoever takes care of it is out of town. No big deal, I wrote a letter and my unit is still at home. Although I wish I had the PV-12, I've still got the PV-10 working perfectly; still got that CJ sound we don't like to live without.

I want to install that transformer before I do anything else, maybe Bill Thalmann could get it, I'll call him

When your audiophile world is right, it seems everything else works out better; my advice to you is, ENJOY, ENJOY, ENJOY.
Ahhhh, neutral, whatever it means as if to say that it is somehow right. The best audio is not "neutral" it is what serves the music in a manner that engages the listener in the performance. If that doesn't happen then neutrality or, another nebulous term, accuracy may appeal to the brain of some that somehow think it "right" but not necessarily to the purpose of music and the end goal. I've given up on trying to reconcile the two, there is none. The only thing that matters is engagement which is less a function of brain but of emotional involvement. While the vintage CJ sound always had an innate "musicality" that is to say engagement factor, improved passive parts can exponentially improve performance and attain greater enjoyment without paying a premium to realize it. The same could be said of many "classic" designs.

I picked up this unit for a really good price and thought it had enough potential to improve on the things I REALLY liked without having to spend a premium for something new. It was a no brainer gamble that worked out quite nicely for me, especially when you are communicating with someone that understands the goals and brings them to your realization. Enjoy the music!

Tubegroover, I know exactly what you're talking about. I bought the original PV-10 that had apparent noise and distortion, but still sounded good. I sent it back to CJ where they made extensive changes to reduce both. I changed the electrolytic in the power supply to "Black Gate" to make it quiet as little mouse; so although it's changed, it's still the same.

Enjoy the music.
"...another nebulous term, accuracy...". Hmmm, interesting choice of words.
I modded my PV10A, would suggest the following based on evolution of my own changes

1) get the CJ replacement transformer, not a substitute
2) replace the big solens caps with Clarity MR caps where space allows these are nicely detailed for sound... Solens wont die with age but are dry/acerbic sounding. if you check your cap voltages, you will likely find that 300v dC rating is adequate in a replacement
3) if the unit has the small white CJ design bypass caps these are likely toast/dulling the highs because of age. replace with VCap like value
4) the stock power supply diode bridge has slow diodes, dulls transients. Replace with avalanche diodes for better transient response
5) add an IEC socket as your existing power cord is probably toast with corrosion inside its wrapper.

If you have the same blue corning resistors as the PV-10A, they are excellent, no reason to replace.
Ok, I have had some brew so have to chime in.

I owned the HK Citation 16 and bought it brand new. A CJ tube amp will destroy it any day of the week with any album, sacd, cassette, cd, or mp3 you want to compare it with.

Bill Thalman is the man and a very easy recommendation. How do I know? He modded a PV11 for me decades ago and did great work at a very fair price.

Expense, Yes, that hurts. How do I know? I sent a pair of CJ 12's from Alaska to the Backert Boys in PA for repair and mods. The shipping was very expensive both ways but the 12's have never sounded better. I just deal with it. Best on Earth, No, I have heard some SET's that just floor me, but the combo of power with the golden glow of old school CJ has me more than satisfied.

Go with Bill or Backert Boys and you will be well taken care of.

Conrad Johnson Rocks!

The PV-10 has received more accolades than any single pre-amp that I can think of. Of course as you go up in number, they cost more and sound better; but the PV-10 is the one more people have bought and heard, round the globe. We love our CJ's with the old school Golden Glow.

Enjoy the music