DC power amplifier with simple circuit

This circuit uses a very simple circuit structure, but its performance is very good. Its principle is shown in Figure 2-25.
    This is a power amplifier circuit with fully complementary symmetry, double differential junction, complementary push-pull voltage amplification, and field effect tube complementary push-pull power amplifier output
. It has no feedback capacitor, so it is a DC power amplifier circuit.
    The differential input stage uses a pair of integrated differential tubes 2SC1583 and 2SA798. Since the parameter
performance is more consistent, and the working characteristics can still be consistent when the temperature changes, it is beneficial to the operation of the whole machine. The stable
    output stage uses a pair of field effect power output tubes 2SK134 and 2SJ49 with excellent performance, which makes the performance of the whole machine
very excellent.
    R7, R and C2 form a negative feedback system, which determines the closed-loop gain of the whole machine.
    In the circuit, the capacitors C3 and C4 connected across the c and B poles of VT3 and VT4 and the capacitor C2 connected in parallel to R
are phase compensation capacitors designed to suppress circuit oscillation. Among them, C and 0 connected between the BC electrodes of the transistor are called lead
compensation capacitors. C2 connected to the feedback resistor Ra is called the hysteresis compensation capacitor.
    Adjust Sha' to adjust the bias voltage of the output tube, adjust RPi to adjust the output midpoint voltage, this machine is lOOnrA.
    If a single tube is selected for the differential tube pair of this machine, it must be strictly matched according to the parameters of each tube to ensure the performance of the circuit .
    Soil I_ _, one