Dual power supply tube power amplifier circuit

The characteristic of the figure below is that it uses dual power supplies. The negative grid voltage of the 6N5P is divided by R3 and R4 and then added to the grid of the power amplifier tube through R5. According to the requirements of different power tubes for negative grid voltage, different voltage division values ​​can be taken. , this circuit is suitable for various power tubes. The ground terminal of the filament of the two tubes in the circuit should be connected to the lower end of their respective cathode resistors, that is, the ground terminal of the 6N5P filament should be connected to the lower end of R6, and the ground terminal of 6N2 should be connected to the lower end of R2 to reduce the distance between the cathode and the filament. potential difference between them. Therefore, the power transformer is required to have two filament windings. The filaments of the power stage and the front stage are powered separately. Note: Be sure to plug in the 6N2 tube before turning on the power. Otherwise, power cannot be applied.