Dongpeng P300 power amplifier circuit

This machine is a product of "Dongpeng Audio and Electrical Co., Ltd.". It uses the excellent "Sanken" power amplifier tube
2SC2922 and Nincrucian Tu 216 as the power output tube. The circuit is carefully designed. The circuit principle is shown in Figure 2-130.
    The input stage of the circuit A bias circuit composed of two diodes is specially designed to ensure the stability of the output zero potential and also
improve the input impedance.
    VTi ~ VT4 form a typical transistor differential input circuit, and adopt a low-noise, micro-current input NEC special tube 9043 with excellent characteristics
and output characteristics. This stage operates at a higher voltage and is equipped with a unique
constant voltage and constant current source circuit composed of VT3 and VT4, which makes this stage extremely capable of processing signals. Ideal, the dynamic range is also very
large.
    VT:s, VT6 form the second stage differential circuit, as the voltage amplification stage, v, r7, VT8 form the mirror current
source load of this stage. Since the collector and base of VT7 are connected, so The output signal of VTs can be directly added to the base of VT8,
so VT6 and VT8 form a push-pull amplifier output to match the complementary push-pull push stage circuit composed of VTio and VTii.
VTt2
    ~VT17 form a three-tube parallel connection. The complementary push-pull power amplifier output stage.
    VTg and other components form a temperature-compensated constant voltage bias circuit. When the temperature changes, the bias voltage of the push tube is automatically adjusted
to make the output stage circuit work stably.