The issue may well be my headamp. The gain was on the high side and I had it lowered to better match my digital system (before vinyl.) My headphones are of high sensitivity, the phono specs are more unknown to me. The Sumiko Oyster at 4 mV (I think) on the Thorens works fine, no issues. I will see if I can borrow a different headphone amp and/or phonostage to trouble shoot. But my guess is the lowered gain I had done on the headphone amp not being enough for the Denon cart.