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.
Please post the scope pictures again. The wires between the choke and the anod power tubes can create some kind of feedback. I would appreciate it if you could post a picture of the amp wiring.
I found the problem. The cables that run from the transformer to the chassis were marked. The copper was visible. They seemed to be touching and inducting each other. I had to remove them to examine them. This is strange because they have rubber grommets. Thanks everyone for the help and the good info and links.
I found the problem. The cables that run from the transformer to the chassis were marked. The copper was visible. They seemed to be touching and inducting each other. I had to remove them to examine them. This is strange because they have rubber grommets. Thanks everyone for the help and the good info and links.
