Three kinds of programmable gain amplifier circuit are introduced in this article. Their applications to electro-acousticsystem are introduced, too.
介绍了程控增益放大器三种电路实现方式，以及这几类电路在电声系统中的应用。
2
The high fidelity meaning is refers to the audio frequency electro-acousticsystem and the equipment or the part maintains the sound signal original appearance ability.