McIntosh Amplifier Repairs
McIntosh MC 2100 Stereo Power Amplifier
This had blown the front RHS channel. The transistors needed replacing on the heatsink, I used MJ1503's, the dual (glued together) front end transistors. The brackets holding (insulating) the heatsinks to the chassis were in bits, so I made some up. The heatsinks are live, one is +ve and the other is connected to the speaker output. Sounded wonderful when repaired.
McIntosh MA 5100 Stereo Integrated Amplifier
This one took out the house breaker when plugged in! I couldn't understand why until I opened the case up and had a look inside. The red wire was connected to the chassis! A novel idea but I don't think it will catch on in the UK, it came from Germany.
Owner reported hiss from the output, replaced the transistors in each channel and a couple of resistors 5k6 which were carbon composition type, several dry joints around the board were also repaired.
McIntosh MA 5100
This was blowing the –ve supply fuse on one channel. Dry joints on the 3600 ohm resistors were suspect, they run hot on the small driver board next to the heat sinks. I replaced the 28V lamps for 24 V ones which are easier to find and replaced the 7.5 ohm resistor for a 22 ohm one for their power supply.