• 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.

Push-Pull Output Transformer with Cathode Feedback Winding?

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I am tracing the circuit of a push-pull 6v6 amplifier from a Webcor 129 console and the output transformer is throwing me for a loop. In addition to the two expected secondary leads going to the speaker, there are three other leads coming off the secondary - one connected to cathode #1, one connected to cathode #2, and one connected to a power resistor which then goes to ground. I presume this arrangement biases the output tubes and provides some sort of feedback, but I've never come across anything like it before. Am I interpreting this correctly?

Also, the power transformer seems to be missing the center tap lead. I have reason to believe it may be grounded to the chassis inside the bell cover, however. Is this a possibility on a mass-market set?



Thanks in advance for any guidance.
-Nick
 
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