＃If a beautiful appearance, good technology and stable quality is the life of an outstanding amplifier, and then high-grade tamber is its soul. If you want a good sound expect for rational frame and nice material, the most important is excellent circuit. Otherwise there will be a flaw in the design. 　　　 ＃There are many types of amplifier circuit such as type A, type B, type C, type D etc., at present the first two types are common used, and the last two types may be applied in digital amplifier in the future. 　　　 ＃From the characteristics of circuit, the distortion of type A is smaller but the efficiency is lower and mute noise is bigger, as compare with, the efficiency of type B is higher, and mute noise is smaller but the bigger distortion is inevitable, so in actually used circuit there are most circuit use type AB circuit which is combine with type A and type B, and make the circuit more effective, high-power, small distortion, and better mute noise. 　　　 ＃There will be big differences between different circuit, although the efficiency of type A is lower the tamber is soft, full-bodied, and it¨s fit for person¨s tone and string music, but for symphony, jazz music and pop music, type AB is fitful for its excellent speed effect and dynamic effect.