Power amplifier circuit with frequency equalization

It is composed of Shoe Delete 1 150Ⅱ with five-band frequency equalization and tone control. Fi power amplifier
circuit. The input pre-stage of the circuit uses NE5532 , and the other half of the NE5532 is used for tone control and also as the pre-stage of the power amplifier.
Wuyin equalization uses the audio power amplifier dedicated hybrid integrated circuit S HM 6325A. This circuit has
the advantages of simple external circuit, easy debugging, and accurate frequency fixing. This circuit also has the characteristics of easy expansion of applications. It can
be expanded into a ten-segment equalization circuit by using two identical circuits.
    SHM6325A is a single in-line 15-pin package. Pin 1 is the input end, pin 3 is the output end, and pin 15 is the power terminal,
pin 14 is the ground terminal, and the remaining pins are the balance control terminals. In the application circuit of SHM
6325A     in Figure 2-108 , its gain control amount is ±12dB, and the center frequencies of each control point are 100H 400ffi, 1 center, 3kHz, and 10kHz respectively.     The maximum power output of the circuit can reach 150w. The power supply can be a simple power supply filtered by a bridge rectifier capacitor. The input preamplifier and equalization circuit are powered by electronically filtered power to ensure the purity of the input stage sound quality.