I acquired all the new parts, and it's together once again.

This time with 100V MOSFETS, a 1.5mH coil and a 5W R1.

I powered it up and measured the positive voltage at 35.8VDC in the circuit.

I tried to adjust the pot to get 17.9VDC at the drains as the Zen documentation indicates.

My problem is, I turned the pot all the way one way and only was able to get the voltage to 20.5V.

It looks like R8 and the pot act as a voltage divider circuit feeding the Gate. So, using math, a 25Kohm resistor would only bring the voltage down to 23.45V. Close.

I need more like a 50Kohm pot in there to adjust it right.

Anyone disagree with this math? Is there another explanation?

I haven't done any other testing. This time it became warm after only a minute or so of idling. So, I wasn't going to mess with it.

Also, I don't have a frequency generator. Anyone know of a good DIY generator? For audio, it wouldn't have to be great, just 20Hz to 20KHz sine waves.

Thanks,