Supply circuit for valve power amplifier - has common grid connection and third voltage source in cathode circuit

摘要

The anode-current supply circuit, for several valve power amplifiers in common grid configuration i.e. earthed grids, has an anode voltage supply (U1) and a grid voltage supply (U2). The anode voltage supply is coupled across both valves (1, 2) i.e. across their cathode/anode paths. The grid voltage supply is connected between the cathode of both tubes and earth but is only connected directly to one cathode. To the other cathode it is coupled over a zener diode (3) (or a transitor or another form of voltage source) acting as a third voltage source.