Common emitter and common base circuit principle

The structure of the cascode-cascode circuit is shown in Figure 2-11. It uses the high output impedance of the common-emitter amplifier tube Vrl and
the low input impedance of the common-base amplifier tube VT2 to provide a constant yce for VTi, and convert the current changes of VTi into voltage
changes. In Figure 2-10, the common-emitter amplifier tube VT7 is used as the input, the common-base amplifier tube VT8 is used as the output, and the constant current source VTg
is the base bias circuit of VT8 .
    VT14 and VTts form a complementary push-pull output stage drive circuit, and VT/3 and RP form its bias circuit .
VT16~VT19 form a symmetrical complementary push-pull power amplifier output stage.
    Rt (33kil), RF (1.2kfl) and CF (220/×2) form a large loop negative feedback, which determines the closed-loop gain of the whole machine.
    The components used in the circuit are selected as marked in the figure, and the adjustment method can be referred to the previous circuit.