CJ Premier 2 No Output

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johnhollier
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Joined: Thu Oct 22, 2015 6:40 pm

CJ Premier 2 No Output

Post by johnhollier » Thu Oct 22, 2015 6:57 pm

Hi All,
I have a Premier 2 which I bought new in 1983. It has been in storage for a number of years (with all my audio equipment) as I have been travelling around. I've now come to the conclusion that I will probably never have the space to properly setup the equipment, so I've been pulling the pieces out and testing them.

The Premier 2 has a problem that I think is caused by the "power on protection". I believe this circuit minimizes the output while the tubes warm up. In previous use, after a little while there would be a fairly loud click and the output would no longer be muted.

I can't get any volume out of either output connections (Output 1 and 2).

I've connected a different preamp to the power amp to eliminate it as the problem. I've swapped cables and checked the cables with other devices to make sure they are OK.

Finally I connected the tape output from the Premier to another preamp's tape input and got audio but at a very low level (not sure if the low volume was just an impedance mismatch issue or something associated with the broader problem).

So, two questions:
1) Does anyone have an idea of what the problem might be and, if so, is it a small fix or a large fix?

2) Is there any market for these old preamps? Looking through the inter-web, the lack of ones for sale/recently sold would tell me No! If there is a market, do you have any idea of a reasonable price?

What I'm trying to decide is, is it worth fixing to sell as "in working order"; do I just sell it for parts; or is it just another paperweight?

Thanks in advance for any input.

John H.

Jim-Analog
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Re: CJ Premier 2 No Output

Post by Jim-Analog » Sun Aug 13, 2017 5:29 pm

Greetings,

John, there is a relay that when energized shorts across the audio outputs to ground for about a minute or so. This allows the power supply and tube heaters to stabilize before it allows the audio to pass. I suspect this relay is not being turned on or has an open coil or perhaps bad contacts (unlikely both channels though).

The circuit is fed by the tube heater voltage, a transistor with a capacitor/resistor combo on the base determines the time constant, which then turns on another transistor to turn on the relay. A pretty simple circuit, but if it fails the preamp is useless.

Typical failures seem to be solder joints under the cap, the cap itself, one or more bad components or less possible, the relay itself. Interestingly the schematic for the P2 does NOT show the switching circuit, just the relay control; so you can't see what the contacts are actually doing. Hope that helps.

Regards, Jim

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