• 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.

Power transformer snerring.

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Hello ThomasS,

At which point are you for your amp?

I don't have your problem but there is the 3a5 that has problems. The voltage is too high. Check this because mine was too high. I doscovered this because I had a hissing problem and it was a consumed 3a5 valve.

Also the resistors are not very good. They look like AllanBradly but they are not. The components also vibrate. I have secured most and have good results.

The new Sovtec valves are much better and they are not the best. The included valves are not very good.

Good luck,
MV
 
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mavallarino said:
The components also vibrate. I have secured most and have good results.

MV


That would be another good reason to re investigate. A power diode going "soggy" trying to s/c itself when hot, a case for checking what's going in and out. With the back of my hand on the chassis one shouldn't feel no buzzing.

I came across sim, (although probably not yours) next door had an US import amp (which went wrong) was used on 230V with same results. The owner forgot to change prim taps.

richj
 
But Lt cdr Data raised one important point - is the mains frequency in order, Thomas S? We have 50 Hz and that does make a notable temperature difference when I test USA equipment, especially with at-the-edge transformers.

I agree on that.

Transformers designed for 50Hz operating at 60Hz is okay, but those designed for 60Hz operating at 50Hz is problematic. I had similar issues of heat and vibration hum when I used 60Hz transformer at 50Hz mains frequency here in New Zealand.

Regards,
James
 
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