For the main purpose, amplifiers can be divided into two major categories, namely professional amplifiers and home amplifiers.

Amplifiers used in stadiums, movie theaters, dance halls, conference halls or other public places, as well as recording and other places, generally speaking, there are some unique requirements in their technical parameters, such amplifiers are often called professional Amplifier.

For hi-fi music appreciation for the family, av system playback, and karaoke entertainment amplifiers, we usually call home amplifiers.

The preamplifier has the main function of performing the necessary processing and voltage amplification on the program signal transmitted from the signal source, and then outputting it to the post-stage power amplifier. Like a railway ramp, it controls which source signal is switched to the amplifier, and which source signal is disconnected from the amplifier.

The post-amplifier is the part that performs pure power amplification. Its role is to be as much as possible, originally amplified locally, from the signal of the previous stage. Our requirement for the latter stage is that the magnification is as high as possible, and the distortion of the amplified signal should be as low as possible. In addition to the amplifying circuit, various protection circuits such as short circuit protection, over voltage protection, over temperature protection, and over current protection are also designed.

These two types of power amplifiers are generally only used in high-end machines.

The combined amplifier combines the preamplifier and the postamplifier into a single amplifier, which combines the functions of the former two. The so-called amplifiers are all combined and have a wide range of applications. Generally speaking, the power of the combined power amplifier is smaller than that of the front and rear power amplifiers, and the playback effect is also worse than that of the front and rear power amplifiers. However, the combined power amplifiers are cheaper and more convenient to use, and can fully meet the general family needs.