Bias Suppply Voltage

[kd]

How much negative bias voltage(minimum-maximum) are ya'll getting out of your bias supply?

Ken

[Pete]

I get -66.8 to -35.10 measured with no tubes installed. Transformer is vintage Fender made for a 100W amp. Pot is 10K with 15K to ground, 1K series off the tap.

How much negative bias voltage(minimum-maximum) are ya'll getting out of your bias supply?

Ken

[kd]

Thanks for the reply Pete. With no load I'm getting about -55 volts to -15 volts. That should be enough range to bias a couple of 6L6 tubes.

Ken

[Structo]

That is plenty of range.

If you are talking about a D style amp, the ODS type amps seem to like the bias set a bit cooler than other similar 2 x 6L6 amps.

Try 33-40 ma first and see what you think.
Of course it depends on what kind of plate voltage you are getting but still, around 55-60% seems to sound good.
Plus your power tubes will last longer.

[kd]

Thanks Tom. I'm about finished building an amp using the ODS 101 non HRM schematic. Waiting on a couple of resistors and caps to get it finished. Just doing a little testing while waiting.

Ken