01-08-2015, 09:35 AM
Main amp has each side fuse protected. When I hooked up the main amp. I tried each side seperately (one fuse pulled). It drew the heavy current either side. For the short time I had power to main amp. I could here a steady hum from speaker and if you touched the chassis or controls the hum got lower. Keep in mind this was at 50 volts on variac and I didn't want to leave it on long. As to main amp. parts I replaced all transistors except Q1 & Q2 these are 2sc458LG. I did remove them from circuit and they tested good. I also replaced all the Ecaps on main amp.
Tested the 2-STV diodes in circuit each test good. They are down in the heat sink and I heard very hard to obtain if bad.
I did not replace any ceramic or mylar capacitors or any resistors.
If there is a overload on B2. That is the control amp. unit. Should I replace the ecaps on it and test the transistors out of circuit?
I have the parts to do it but don't want to change too much for fear of creating a problem that is not there.
Tested the 2-STV diodes in circuit each test good. They are down in the heat sink and I heard very hard to obtain if bad.
I did not replace any ceramic or mylar capacitors or any resistors.
If there is a overload on B2. That is the control amp. unit. Should I replace the ecaps on it and test the transistors out of circuit?
I have the parts to do it but don't want to change too much for fear of creating a problem that is not there.
