摘 要
本文主要介绍实用低频功率放大器。本文首先对功率放大器的课题背景作简要的说明，随后对功率放大器的一些基础知识进行介绍。此外，相应的介绍低频功率放大器的各单元电路———前置放大、音调控制电路、音量控制电路和功率放大部分的组成与工作原理，详细叙述了音量控制电路部分。
通过分析低频功率放大电路,对功率放大器进行深刻的阐述。功放电路为本机的主放大器,它的输出波形容易受前置级的影响，本文在调试部分对功率放大器出现的干扰、自激振荡现象等做了细致的分析。此外,本文对整个电路的工作原理进行详细的描述。
{zh1}，本文具体叙述实用低频功率放大器的安装与调试，并对电路在工作中易出现的失真情况做了细致的分析。

关键词 低频功率放大器；前置放大；音调控制电路；音量控制电路

Abstract
This article main introduction practical low frequency power amplifier.This article first to has carried on the introduction with the power amplifier related some knowledge.Afterwards can the corresponding introduction power amplifier unit electric circuit - pre-amplification, the tonality control circuit, the volume control circuit and the power enlargement part.Through the analysis low frequency power enlargement electric circuit, has carried on the profound understanding to the power amplifier. The merit puts the electric circuit for the this aircraft main amplifier, but the negative feedback in the conductive coupling enlargement electric circuit can the effective stable operating point, therefore this article will make the detailed analysis and the estimate to them. In addition, this article will also carry on the careful analysis to the entire electric circuit principle of work.
Finally, this article can in detail narrate the practical low frequency power amplifier installment and the debugging, and to debugs the question which in the process appears to give the briefing.

Key word Low frequency power amplifier；Pre-amplification；Tonality control circuit；Volume control circuit

目 录

摘要 ......................................................................I
Abstract .................................................................II

第1章 绪论..................................................................1
1.1 课题背景................................................................1
1.2 功率放大器的基础知识......................................................2
1.2.1 功率放大器的作用 ......................................................2
1.2.2 功率放大器的电路组成 ..................................................3
1.2.3 信号源和负载..........................................................4
1.2.4 功率放大器的种类 ......................................................4
1.3 功率放大器的性能指标 .....................................................5
1.3.1 失真度................................................................5
1.3.2 频率响应..............................................................6
1.3.3 输出功率 .............................................................6
1.3.4 输入电压 .............................................................6
1.3.5 音调控制范围...........................................................7
1.3.6 信噪比 ...............................................................7
第2章低频功率放大器的分析 ....................................................8
2.1 整机电路的组成 .........................................................8
2.1.1 功率放大器的主要技术指标 ...............................................8
2.1.2 电路说明 .............................................................8
2.2 单元电路的设计与分析.....................................................9
2.2.1 前置放大器 ..........................................................9
2.2.2 音调控制电路 ........................................................10
2.2.3音量控制电路 ..........................................................11
2.2.4 功率放大电路 ........................................................17
第3章 低频功率放大器的安装与调试 ............................................20
3.1   电路安装与调试技术 ....................................................20
3.1.1 合理布局、分级装调.....................................................20
3.1.2 调试技术..............................................................20
3.2   电路的调试 ...........................................................21
3.2.1 抑制干扰、噪声和xx自激振荡 ...........................................21
3.2.2 前置放大器输入、输出电压的测量 .........................................24
3.2.3 功率放大器的功率计算 .................................................24
结论 .......................................................................25
致谢 .......................................................................26
参考文献 ....................................................................27
附录1 译文 ..................................................................28
附录2 原文...................................................................30
附录3 原理图 ................................................................33