I have a 4270 on the bench.
Initial report.
Intermittent loud short circuit like sound and act on one amp.
There was some small popping and crackle like a bad cap after it finally started to act up.
Some finger poking the input coupling cap seemed to cause more noise, popping and crack.
Tossed all new caps on the amps.
Amps adjust very well but DC offset at zero when trimmer at max turn on flacky amp.
Runs great, sounds great. Then bzzzap. Tossed into protection. Then pops back and plays fine.
It is the amp. Noise was isolated to the amp using the IN/OUT jacks. Noise would occur at zero volume.
Trimmers seem ok, adjustment shows smooth changes when moved.
Blob diodes replaced.
Intermittent sucks.
Anyone figure out one like this?
Initial report.
Intermittent loud short circuit like sound and act on one amp.
There was some small popping and crackle like a bad cap after it finally started to act up.
Some finger poking the input coupling cap seemed to cause more noise, popping and crack.
Tossed all new caps on the amps.
Amps adjust very well but DC offset at zero when trimmer at max turn on flacky amp.
Runs great, sounds great. Then bzzzap. Tossed into protection. Then pops back and plays fine.
It is the amp. Noise was isolated to the amp using the IN/OUT jacks. Noise would occur at zero volume.
Trimmers seem ok, adjustment shows smooth changes when moved.
Blob diodes replaced.
Intermittent sucks.
Anyone figure out one like this?