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.

Mission 777 Stereo Power Amplifier Mission 777 Stereo Power Amplifier Mission 777 Stereo Power Amplifier Mission 777 Stereo Power Amplifier Mission 777 Stereo Power Amplifier