VVR in a cathode bias amp

[crocket]

Would lowering the HT voltage without altering the power tube bias resistance induce cross over notch distortion?

[UR12]

Would lowering the HT voltage without altering the power tube bias resistance induce cross over notch distortion?

By "Bias resistance" I am asuming you are talking about a cathode resistor resistance. Since the bias voltage is dependent upon the voltage drop across the cathode resistor (bias resistor), The bias is developed depending on how much current the power tubes are drawing. As you lower the plate voltage you decrease the current flow through the tubes and lower the voltage drop across the cathode resistor. That changes the bias automatically when you lower the plate voltage.

On a Fixed bias amp, you will need some method of lowering the bias voltage to the tubes in proportion to the lowering of the B+ plate voltage. If you lower the HT on a fixed bias amp without altering bias voltage you will create crossover distortion.

[crocket]

Thank you for clearing that up Dana. Thank you so very much.