一、输入级放大器的输入级,几乎一律都采用差分对管放大电路。由于它所处理的信号很小,由电压差分输入给出的是与输出端口处电压基本上无关的电流输出,所以它与输出级放大后的信号相比,其线性问题容易处理。但是,对输入级的设计也不能轻视,因为一个错误认识设计出来的输入级,即便是稍有不妥,也会很容易地出现对整机高频失真起主宰作用。 First, the input stage amplifier input stage, almost all use differential amplifier on the tube. Because of the small signal it processes, the voltage differential input gives a current output that is essentially independent of the voltage at the output port so that it is easier to handle than the amplified signal at the output stage due to its linearity. However, the design of the input stage can not be ignored, because a misunderstanding of the design of the input stage, even if slightly wrong, will easily appear to dominate the machine high frequency distortion.