Help please tracking down distortion

[Fishfood]

I've been chasing down some distortion in my analog setup, which is a Garrard 401/SME 3012R and an Ortofon SL15 cartridge most of the time. I've got the setup dialed in decently finally but I'm still getting some distortion on high end peaks once or twice a side in the right channel.

Now here's the twist- when I swapped the phono cables, left to right, going into the SUT, to check if it was maybe the speaker, the distortion went away. Swap them back and it's in the right channel again.

Any thoughts? I'm totally confused by this.

 

[mtemur]

Swap the channels on phono pre input not SUT. If distortion flips to left channel than it’s a possibility of a SUT problem. Maybe SUT is converting balanced to single ended only on right channel or maybe the tonearm is doing it. Unmount the cartridge then check with a meter if signal negatives are connected to ground on tonearm and SUT.