• WARNING: Tube/Valve amplifiers use potentially LETHAL HIGH VOLTAGES.
    Building, troubleshooting and testing of these amplifiers should only be
    performed by someone who is thoroughly familiar with
    the safety precautions around high voltages.

Oscillating CJ PV-5

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Hi. I think this is my first post.
I am having a bad problem with a Conrad Johnson PV-5.

It started to rustle badly in the right channel, so started wiggling and swapping tubes, and moving the pots and selectors around to try to fix/find the source of the noise. Then the rustling got louder and spread to the other channel. I then noticed that the 5751 and the 5965 were switched in the phono stage and that the phono stage would oscillate badly when I turned up the volume. I tried changing some of the diodes on the power supply, as I have had these go bad before. When I turned the preamp on again,a bad hum had joined the party, so I changed the diodes back. No change.

Now I have a humming, badly oscillating preamp that rustles.

Any ideas?
 
The hum was a PS diode, and it looks like the restof the trouble is caused by the relay switch that lets the preamp warm up before starts operating. Is there a way to bypass this relay? It has been cleaned before, and even still it only worked in one channel. I would like to get rid of it.
Thanks
 
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