valve rectifier in PSUD

[Palustris]

You would need a 250W minimum 1500ohm resistor. That doesn't sound practical. I would breadboard with the OP tubes and bring it all up on a variac for testing.

As long as you have the heater current available you could sub the 5AU4 any time you wanted. You might be surprised to find that even with the 30V less B+ the amp sounds better. You never know without trying.

 

[Sheldon]

If I understand correctly you have a current peak at start up that violates the max current for the rectifier.

This current peak is only "on paper". In actuality the current through the output tubes will not ramp up for several seconds. The way to model this is to use the current step feature offered by PSUD. Click on stepped load. Add value 1 at maybe 2mA then add Value 2 at your expected current draw say 248mA after 2 second so you total is the 250mA.

By using the stepped current feature gives a much more accurate view of the way the amp actually powers up. If you want to be really accurate, time the actual time to current draw of the tubes in your model. Don't forget to do this for all the stages as the driver and voltage amp tubes do not conduct instantaneously either (neither does the rectifier). I think you will find that your PS will be fine and your rectifier tube will not be stressed at all.

There is also a slow start option, in the options menu. It doesn't ramp up as slowly as an indirectly heated tube, but it's still more accurate than without. The regular (non-slow start) would model SS diodes.

Sheldon