音源设备输出的音频信号, 先经过前置放大器 进 行 无 失 真 预 放 大 , 数 字 音 频 处 理 器TDA7315 在单片机 AT89C52 控制下, 对输入音频信号进行自动调整, 使输出音频信号幅度达到预定要求。AT89C52对 TDA7315 输出信号进行采样分析, 实现对 TDA7315 的音量自动控制。系统同时附有显示输出信号电平、设定输出电平功能。-Audio signal output　audio equipment, go through the pre-amplifier distortion-free pre-amplification, digital audio processor TDA7315 single-chip AT89C52 under control, the input audio signal is automatically adjusted so that the output audio signal amplitude reaches the predetermined requirements. AT89C52 output signal is sampled for analysis TDA7315, TDA7315 volume to achieve automatic control. System simultaneously with the display output signal level, the output level set function.