Mission Amplifier Repairs
Mission 777 Stereo Power Amplifier
One channel had blown resistors and transistors; 2SB646, 2SD666, 220 ohm, 390 ohm. I replaced these with great difficulty as the holes are through plated, also replaced the o\p FETs. The o\p DC level on one channel was slightly higher than usual, so made a small PCB to adjust the DC level and set the quiescent current at the same time. I also fitted a soft start to the Mission 777 power amp to save the mains switch from welding itself together.