Well, my stereomour is not even technically well broken in but it seems that I'm reaching the conclusion that one of the tubes is bad/going bad.
I noticed severe volume discrepancy on the left channel tonight, and after checking all connections, and changing music sources, I thought I would try the simplest test and simply power it down and swap tubes.
Bingo, the right channel now is severely diminished.
Only possibility is failing tube, right?
Esoteric DV-50, Technics SL1200-M3D, B&K Phono 10 Preamp, Sumiko Blue Point Special Evo III, Bottlehead Stereomour, Orca's