Feedback circuit of transistor amplifier 5

The above introduces the negative feedback of a unipolar amplifier,diode  also known as small loop negative feedback. Small loop negative feedback plays an important role in improving the performance of amplifiers at all levels. For multi-stage amplifiers, feedback signals are often taken from the output and sent back to the input, which is called large loop negative feedback. The large loop negative feedback has a significant effect on improving the overall performance of the machine. The negative feedback network, as shown in Figure 5-59, consists of routes Rm, RF2, and CF. It takes a negative feedback signal from the secondary of the output transformer, divides it by RM and RF2, and connects it in series at the input end of the amplifier.diode CF is a negative feedback capacitor designed to improve the frequency response characteristics of amplifiers. It can enhance the negative feedback of high-frequency signals, making the amplifier's bass appear stronger and reducing high-frequency noise. This series voltage negative feedback increases the input impedance of the amplifier and decreases the output impedance. It is a two-stage amplifier that uses parallel current negative feedback. Using RF, the current feedback signal is obtained from VT2 and sent to the base of VTl through RF2. This negative feedback reduces the input impedance of the amplifier and increases the output impedance diode