Meet Vivi, longtime CJ owner. Sorta. in NYC.

[admin]

Glad to hear you got the turntable set up.

I know it can sometimes be frustrating to have some lingering issues pop up. As for what component is causing the right channel failure, it's actually pretty easy to determine without having to take things apart. You can flip the right and left RCA cable from the preamp to the amp and if the occasional dropout happens in the left speaker, it's the preamp. If it still happens in the right channel, you know it's the amp (presuming it's not actually the speaker, but that could be ruled out via switching the speaker cables).

Keep us updated.

[vivi]

Thanks for that idea.
I left the radio on for three hours and the right channel performed like a champ.
I just plugged in the CJ and the turntable and the right channel is working. I am timing it to see if there's a set time the right channel conks out. Meanwhile, Marshall Tucker. Can't you see, oh can't you see, what this CJ, has been doing to me.

[vivi]

Okay, I tried the turntable again. both channels worked for 15 minutes, then the right channel faded and came back, but sounded like it was getting softer and lower. then it went silent.
Switched right and left and tried again. Right channel worked, left channel worked...and then faded a few minutes later.
switched back to normal and now the right channel is working again and so is the left...for four minutes and then right channel went out again.
????

[vivi]

Forgot to add that when I switched RCA cables, the left one went out and the right one worked. If it flat out didn't work at all that would give me some definite data, but I can't make head or tail out of this. The power amp and both speakers work for hours when not connected to the CJ - I used it with my mp3 and with my Bose radio/CD player.
Use the CJ with the turntable and I get diminishing amounts of listening time out of the right speaker, although I get a bit of static when I move the CJ RCA cable. I can try another RCA cable, but that's a two person job.

The Linn guy said the turntable worked fine after he fixed it and played it on his system but that could be a head fake...because the way this damned thing messes with me is that it works fine at first...for a while. So I don't know if it worked fine because the Linn is fine, or if he simply didn't play it long enough.
suggestions?

[DECO_WKSHOP]

Hi Vivi,

I have been asked to see if I can shed any light on your on-going problems. I've read through the four pages and think I've taken it all in but forgive me should I ask a question or two that you may have already answered !!!
Also, I am not that familiar with all CJ gear. I've been repairing Hi-Fi for over 30 years but mostly 'Mid-Fi', only in the last 5 to 7 years seeing more high end gear and therefore one or two CJ bits and pieces.

So, firstly, am I correct in understanding that the 'fault' now only occurs when using the T/T ? (LINN)
I am not familiar with the PV-1 but am guessing it has a dedicated Turntable/Phono Input (?).
The Deck has been looked at by your local chappie and given a clean bill of health as he used it for some time and both channels OK (?).

Well, my first thoughts are that it is going to be something to do with the PV-1's dedicated Turntable Input.
The Output from a T/T Cartridge is much, much smaller in leverl than a 'Line' Level Source such as a CD Player or Tuner. It also is not 'Flat' in its Frequency Response, the mechanics of being able to record onto a Vinyl Disc prevent this so the Low Frequencies are reduced and the High Frequencies are accentuated (this is why when you just put your ear next to the Tonearm whilst its playing all you can hear are the High Frequencies).
So, to be able to reproduce the Music correctly, in the PV-1 there is a circuit which, amplifies the signal to make it the same level as your CD Player or Tuner and it 'corrects' the Frequency Response by boosting the Low Frequencies and reducing the High Frequencies so that what is outputted from the PV-1 and fed to the Power Amps and Speakers has a 'Flat' Response and sounds natural.
I suspect that it is this circuit that has got an intermittency in its Right channel.

I understand that the PV-1 is a Valve based Amp (?) (I'm English so we call tubes, Valves!!!).
So, I think maybe firstly, if it's not been done, after the Power has been Off for at least half an hour, take each Tube (!) out, one by one so as not to get them mixed up and re-insert them. Doing this will clean the Pins of the Tube and the Socket too. If there's any Oxidisation ocurred, which can cause intermittent contact, then this action will clean it off.
I realise it's all in your Rack and this 'simple' task isn't so simple but you've come so far it's got to be worth a try (?).
If that doesn't work, then maybe one of the other contributers to your thread can help with the identification of which Tubes are for the Phono Stage. I think there was mention of a Link to the Instruction manual earlier so I will see if I can find out too.
If there are different Tubes for each channel we can try to swap them over to see if the 'fault' changes channel. It is entirely possible you have an intermittent Tube. You mention that sometimes the sound fades away so it could be that when warm, the 'Heaters' within the Tube become Open-Circuit, the Tube cools and stops producing Output.

I think that'll do for my first go at help, if you've already tried these then I apologise for not reading you'd mentioned it !!

All the very best for now,

James.

[admin]

Here is the manual with the tube location information: https://conradjohnson.com/owners-manuals/pv1man.PDF

Just be real careful with opening the unit and making sure to give it ample time for the capacitors to discharge. I would also recommend doing this with non-conductive gloves. You don't want to get skin oil on the tubes.

[DECO_WKSHOP]

Thanks admin for the link to the Instruction booklet.
I've also looked at the ServiceManual and it is V1, V2 and V3 which are for the Phono stage so, at first maybe we concentrate on these.

Once you have left the Amp in the Off position for at least half an hour then pull these Tubes out and re-insert them one by one. They may, and should be reasonably well held in place so some gentle but careful force is necessary. Use one hand and place your other above the Valve in question so if it suddenly comes out, it doesn't hit anything which may be above it apart from your hand. I have seen this happen many times when the Tube is pulled out and smashes on the shelf above !!!

Don't worry too much about the oils in your skin, small Signal Valves such as these 12AX7's don't really get hot enough to worry about hot-spots forming on the glass. An O/P Tube in a Power Amplifier is a different matter.
If you like, once the Tube is back in place, you can clean it with a soft cloth.

I would have hoped your local repairer would have done this but initially it's got to be worth a try.
If your problem persists then it may be we start to replace these Valves one by one. They're not too expensive and should it prove to not be the Tubes then you have bought some spares for any problems in the future.

The Input Selection Switch has also got to be a contender as the culprit for your problem.
When the fault does ocurr, can the sound be got back by moving this Switch in particular but any of the Controls?

All the best,

James.