Did you try swapping the RCAs over at the phono preamp inputs to see if the problem is the turntable or the amp ?
You could also swap the channels at the cartridge to see if there is a tonearm wiring problem.
Alignment / VTA problems have always manifested as distortion in both channels for me, never in only one channel.
You could also swap the channels at the cartridge to see if there is a tonearm wiring problem.
Alignment / VTA problems have always manifested as distortion in both channels for me, never in only one channel.