Hi folks. I fully rebuild the amp board and power supply board on a 2215B, as seen here. Both channels were blown, so I fully recapped/re-transistored the amp and power supply boards. I replaced all the electrolytics and tantalum caps with the same values (though some are up in voltage) and I replaced all the transistors with the ones suggested here. I biased both channels to 10mv as per the service manual. Power supply voltages are all fine or are 5-8% over.
This plays nice and loud, but at any moderate to loud volume, both channels are very slightly distorted. It's very clear with a signal generator, and much harder to tell with music, but music just sounds "off" a bit. All inputs are like this. I tried directly injecting a signal into the amp board and the issue is still there. I got all the cap polarities correct and I'm pretty sure the transistors are all in right. It biases up fine. Both light bulbs on the amp board are good. Any ideas?
This plays nice and loud, but at any moderate to loud volume, both channels are very slightly distorted. It's very clear with a signal generator, and much harder to tell with music, but music just sounds "off" a bit. All inputs are like this. I tried directly injecting a signal into the amp board and the issue is still there. I got all the cap polarities correct and I'm pretty sure the transistors are all in right. It biases up fine. Both light bulbs on the amp board are good. Any ideas?
