12-03-2012, 10:08 AM
The power supply while filtered are not regulated. The B+ voltage is largely dependent on the load. The big load comes from the audio output section. If there is a bias problem or only half the push-pull is working that could explain a lot.
Make basic voltage checks on 42 output tubes with emphasis on the bias. Voltage chart is saying 15V of bias (K to CG). Low voltage on one of the plates could mean a open section in the audio output transformer.
Make basic voltage checks on 42 output tubes with emphasis on the bias. Voltage chart is saying 15V of bias (K to CG). Low voltage on one of the plates could mean a open section in the audio output transformer.
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