该设计采用的是NE5532芯片组成前置放大电路将输入正弦信号放大，实现负载输出功率大于等于5W的要求。通过分立MOS管组成的互补放大电路，增强功率放大和驱动能力，以驱动8Ω负载。功率放大器的输出功率、电源的供给率通过STC89C52单片机的中A/D转换器取样计算，从而得到整机效率，并显示在LCD的显示屏上。采用带阻滤波电路可以有效抑制交流电源对放大器的影响。该系统的设计实现了输出功率范围在10Hz—50KHz，功率大于5W的模拟信号，且误差在5 以内，信号无明显失真。-This design USES is composed NE5532 chip preamplifier circuit will input sine signal amplifier, realize the load power output is equal or greater than 5 W requirements. Through the division of MOS tube complementary amplifier circuit, enhance power amplifier and drive ability to drive eight Ω load. The power amplifier output power, power supply rate through the STC89C52 SCM in the A/D converter sampling calculation, and get the whole machine efficiency, and displayed on the LCD display. The band elimination filter circuit can reduce the ac power to the influence of the amplifier. The design of the system realized the output power range in 10 Hz ac-50 KHz, power is greater than 5 W analog signals, and the error within 5　and the signal no significant distortion.