03-22-2015, 12:40 PM
Final thoughts before I put this back on the shelf for awhile:
I did turn it back on a little while ago and made a few voltage measurements.
At first it sounded OK, and then distortion slowly crept into the left channel. After a few minutes, distortion in the right channel would appear, disappear, and reappear.
Voltage at the emitter of Q20 was 22.5V and held steady.
Voltage at the emitter of Q19 also held steady, at 15.9V.
Now here's where it gets interesting. I measured the voltage across C55. When the right channel was clear, the voltage was 44.1V. But when distortion appeared in the right channel, it increased to 44.7V. The service data calls for 42V.
All rectifier diodes were previously replaced (by me).
I did turn it back on a little while ago and made a few voltage measurements.
At first it sounded OK, and then distortion slowly crept into the left channel. After a few minutes, distortion in the right channel would appear, disappear, and reappear.
Voltage at the emitter of Q20 was 22.5V and held steady.
Voltage at the emitter of Q19 also held steady, at 15.9V.
Now here's where it gets interesting. I measured the voltage across C55. When the right channel was clear, the voltage was 44.1V. But when distortion appeared in the right channel, it increased to 44.7V. The service data calls for 42V.
All rectifier diodes were previously replaced (by me).
--
Ron Ramirez
Ferdinand IN
