Here is my single triode vacuum tube amplifier circuit I understand there needs to be a bias on the grid otherwise the signal will be rectified -not amplified. Is biasing the grid as simple as running a resistor in-between the grid and the cathode on the power supply like this (in red)? From my understanding, the ideal bias voltage on the grid would be -150V. This would allow the waveform to equally fluctuate from 0V to 300V within your rail voltage. So? So the cathode from the supplied voltage is 0V. How is wiring a resistor in series from the grid to the cathode giving you -150V on the grid? There is something about relative potential that I am not seeing.