BK Electronics Amplifier Repairs
BK Electronics MXF200 MOSFET Amplifier
This one was buzzing on one channel, looking inside showed the main capacitors were u\s 4700 µf 63V.
BK Electronics MF300 MOSFET Module
This is an old power amplifier from the 1980's, before using it I thought it would be a good idea to give it a check out. The MOSFET's were removed and the heat-sink compound replaced. The TO126 transistors which are riveted on to the heat-sinks were checked for tightness, some were loose. The original capacitors 10000 µF 80V were replaced with modern smaller ones. I decided to replace the main caps with more up to date ones, made an 'interface' board to support them. There is a solder link to check the quiescent current, it should be about 60-80 mA. Sounded okay at switch on.