Does anyone know the current used by at 12Ax7 (or similar) vacuum tube when in normal (triode) operation using a plate voltage no more than 10VDC? I'm not considering the heater current (~300mA at 6.6V), just the grid to plate current or the current drawn from the power supply. I've simulated the tube in MicroCap with little luck and I don't have my equipment to physically test it.
Electronic – Plate current use of 12Ax7 vacuum tube at low voltage
low-voltagevacuum-tube
Best Answer
Looks like anode to cathode current will be in the 400uA range with zero grid voltage ("Idss"). 6AV6 has the same characteristics as the 12AX7 according to the databook.
Edit:
LTspice with the RCA12ax7 model yields a plate current of 417uA.
Model:
You can find some more info on this particular model here