４８２．甲类前置放大器现在，前置放大器的设计都是以集成电路为基础，几乎无新的变化。然而，喜欢分立式电路设计的人仍然很多，他们喜欢这里介绍的这种电路。放大器的设计是对称式，在差分输入级中，使用两个晶体管Ｔ＿１和Ｔ＿２两管之间的电流放大之差，在输入级要作... 482. Class A Preamplifiers The design of the preamplifiers is now based on an integrated circuit with virtually no new changes. However, there are still many people who like discrete circuit design, and they like the circuit described here. Amplifier design is symmetrical, in the differential input stage, the use of two transistors T_1 and T_2 two current amplification between the two ...