• 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.

Copland 501 no sound, NEWBIE

Sorry if this is an absolute newbie question, but recently I optained a Copland 501, but during testing of the amp, I didn't manage to get any sound out of it.

Before first power-up I inspected the board and messured the R31-R32, R131,R132.

Follwed a bais procedure, and adjusted everthing and it looked fine.

But while running the tubes 3 out of 7 tubes light up, to give more info, all four aeg 34 tubes don't light so it seems.

I'm I doing something wrong, are the aeg tubes faulty ?

Thanks in advance for advice


2001-10-26 11:51 pm
Given that the 4 aeg34's, presumably these are the 4 EL34 power tubes, do not light up you need to check the heater supply or its fuse. If it is not obvious at sight you can track it down by tracing back from the heater supply pins for each tube, pins 2 and 7.