This Yamaha CA-810 integrated amp was sent in for evaluation and some restoration work. It was found that the left channel was clipping slightly quicker then the right. Overall the unit is incredibly clean with no cosmetic defects. The amp has a differential controlled offset so there is no adjustment for DC offset. The bias can be adjusted by a trimpot for each channel on either side of the main board. All electrolytic capacitors were replaced, mostly with Nichicon KW series. Some low leakage caps were replaced with Nichicon KL, and bipolar electrolytics with ES series. The large filter caps were replaced and bypassed with 2.2uf 250V stacked film caps on the trace side of the board. Testing will be done once the amp has played for several days and the bias rechecked. Immediately I can hear a vibrance to the tone and plenty of headroom. Here are a few pics of the work.
Function board




Main and tone board. Tone board already done with new supply caps. Bypass caps on trace side.



Big size difference in capacitors


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