Actually I meant another electronic component in the circuit. For example a wire or a tube in the Seduction itself could be picking up transformer hum of the PT-1. This is measurable in a Seduction in the right channel due to the proximity of the circuit components to the power transformer, though it is seldom noticed by ear unless the cartridge is a very low output type. But variations in sensitivity to hum pickup can vary quite a bit from tube to tube. That's why it is difficult to quote a "normal" figure. Since this problem only seems to be present when you listen with headphones and not with speakers it seems like it may be right on the threshold of what could be considered normal. And that is why I feel that I would have to listen and measure it myself to give a more confident answer about whether it is typical or atypical performance.
