Bill Messages: 64 Registered: March 2002 Location: Kansas
Member
I bought a k150-8, non working, pilot light works, no sound at speakers. Found someone had reversed the monitor and speaker outputs on the output board, wired the speakers as a short. I fixed these things and now have signal all the way through the amp, but it has a whoop-whoop-whoop sound, that is not affected by the volume or other controls,puts out about 20 volts ac--don't see any dc. Someone has replaced one driver with an SK3024, and the thermal diode was replaced by a 116 diode, and not placed in the chassis heat sink. Three other transistors have been changed on the premap board. I will try to isolate where it's coming from--either preamp or power board first.
Bill C