Two-channel audio power amplifier circuit diagram analysis

This article mainly analyzes the circuit diagram of the two-channel audio power amplifier. I hope it will be helpful to your study.

The picture shows a 2×30W two-channel audio power amplifier. Its core device ICl uses the high-fidelity audio power amplifier integrated circuit STK465. This circuit contains two power amplifiers with exactly the same performance indicators, which are used as left and right channel power amplifiers respectively. It can ensure the consistency of the two channel amplifier indicators.

The circuit input impedance is 30k, the input sensitivity is 150mV, the voltage gain is 40dB, the frequency response is: 10Hz～100kHz, the harmonic distortion is ≤0.08%, and the power supply voltage range is ±(25～35)V.

When making, it should be noted that the positions of the positive and negative power supply decoupling filter capacitors C5 and C14 should be as close as possible to the positive and negative power input terminals of sTK465 respectively.

If the circuit has self-excitation, increase the capacity of C5 and C14. The power amplifier has moderate output power and is easy to make. It can be used as a sound player for general home audio systems, karaoke equipment or VCD machines.

Since the voltage gain of this power amplifier is as high as 40dB and the input sensitivity is high, the preamplifier can be omitted and directly connected to signal sources such as karaoke machines and VCD machines. This amplifier can also be used as a surround sound amplifier for home theater systems.