LMl876 is used to assist the audio power amplifier circuit

As shown in the figure, LM1876 is used to assist the audio power amplifier circuit. The audio input signal is added to the input terminal 8 pin of LM1876 after passing through the potentiometers RV, CIN, and RB. After amplification, it is output from the 3 pin and sent to the speaker through L and R. RV is the volume potentiometer, which is used to adjust the volume; RIN is used to set the DC bias operating point of the amplifier, and at the same time, it forms an input high-pass filter with CIN; RSN and CSN are used to reduce the instability of the high-end frequency of the amplifier; L and R provide high resistance to high frequencies and low resistance channels for audio to prevent high-frequency self-excitation.