The power amplifier part is adopted with FET (Field Effect Transistor). The amplifier circuit is assembled in three-stage pure complement mental discrete differential input, such as the mutual interference of the unwanted signal in the circuit, We reduced a variety of adverse effects, the one that consisted a problem in sound quality. In addition, it is equipped with a Phono equalizer amplifier (MM type) providing the possibility to connect to analog record players. Input and output terminals used are a gold-plated type with an emphasis on sound quality. In addition, it is equipped with system functions (interlocking functions) of the CD player "CD-P650", as well as playback with supplied remote control and operations such as stop. The "A-R630MKII" is a simple and versatile stereo pre-main amplifier equipped with abundant input terminals.