My 18 years old Cayin 270P power amplifier has stopped working in left channel.
Please see attached schematics (uploaded to this forum by a nice Norwegian back in 2012)
Left Channel :
I can measure -10VDC on the output.
The PSU's are all fine, that is +-70V and +-55V.
On Q209 base is -14VDC, on Q208 base is -10VDC
On the working right channel, the same figures are -1.2VDC and +1.2VDC
Any suggestions would be appreciated.
Best Regards
Poul
Please see attached schematics (uploaded to this forum by a nice Norwegian back in 2012)
Left Channel :
I can measure -10VDC on the output.
The PSU's are all fine, that is +-70V and +-55V.
On Q209 base is -14VDC, on Q208 base is -10VDC
On the working right channel, the same figures are -1.2VDC and +1.2VDC
Any suggestions would be appreciated.
Best Regards
Poul
According to your schematic there should be +/- 55Volts DC feeding both sides of the output devices .
If you are measuring -10Volts at the output I think you have a failed component rather than an imbalance relating to the input.
I would check the components on the amplifier negative side for a short circuit,especially round the bias and driver section.
If you are measuring -10Volts at the output I think you have a failed component rather than an imbalance relating to the input.
I would check the components on the amplifier negative side for a short circuit,especially round the bias and driver section.