Marantz 1060 Left channel distortion and low output.

[grindfix]

Problem is with Power Amp. Connected mp3 player to main-in. Right Channel normal, Left channel is distorted. It starts out kinda like dirty pot sound and if volume is raised Left side will go almost silent within several seconds. Turn it down, wait few seconds and try again same distortion and volume drops within few seconds again. There is no distortion (or almost no distortion) through headphones until speakers are connected and turned on. I've tried substituting output caps with no effect. I don't have a scope. Multimeter and cap checker only, so I could de-solder and test all electrolytics and transistors but would be great to know if anyone knows any common components on the amp board before I start.

 

[tonebells]

Sounds like bad outputs.

Tony

 

[mbz]

Outside chance it could be dirty speaker selector switch, since it works ok through headphones. OK, headphones are higher impedance than speakers
so not so brutal on the amp. You could try playing it loud through the headphones and check for distortion. Suggest also checking the bias just as general
health check and confirm everything responds to the bias adjustment.