400W Stereo Audio Amplifier based on the original Marshall Leach involvement, but has made some improvements. Regarding the power supply voltage to the +-75V. VC comparing the performance of the modified Leach 700W/2R on one common board of both channels, as well as protection and control circuits for the fans. Compared to the 700W version a bit different in wiring. Because some things in the 700W version is completely tightened to perfection. 700W version could criticize a couple of things: 1st very high gain output stage resulting in deterioration of signal noise distance. Therefore 700W version even more noisy. 2nd The absence of multipliers Ube bias current control and maintain temperature stability diag...