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Re: One step at a time.

Seems to me that your power tubes are fine and I don't remember what the B+ dropped down to (seems a little low but not too much it's less than 10%). As long as the current through the power tubes remains stable after things warm-up you should be just fine. What is the voltage at the test points after 30 minutes or so? Is it the same after an hour? Have you disconnected the feedback yet? You need to keep the inputs shorted and disconnect the feedback. You should have more hum than just the power section alone, but let's see if it is less than with the feedback connected.

The other area to look at is the heater voltage. Have you checked, double, and triple checked your heater center-tap connection? As well as the connection to chassis? Did you remove the paint at that connection? Is there any DC or AC voltage the the heater center-tap? Verify that there is a dead short between the power safety ground and the circuit ground. Do a visual inspection of the heater wiring on the PWB and make sure that the heater wires (bare wire) and solder connections are not in contact with anything else.

Lots of things to look at. And...who knows, it may turn out to be a tube after all.

Keep at it. You'll find it.

Pete.

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