Pioneer SA 9500 mk 1

[bikey022]

I have a pioneer SA 9500 mk 1 and when i increase the volume to the 2nd click it start to have distortion. May i know what is the problem ? I have changed the transistor in the preamp side. I suspect is the power supply section as i increase the volume it draws higher current causing the distortion.

 

[amptech]

Test the o/p devices... These old amps suffer from bad dry solder and cracked pcbs.... You can apply a signal into the preamp stage and bypass the preamp to check if the o/p stage is at fault...