I haven’t found an answer to this question in searches, either in the instructions (which I assume were meant to be non-coercive: “choose your preference!”), or on this site or the internet.
Depending on the recording, I might prefer a non-standard setting (i.e. inverting a recording that was recorded normally), but I’d still like to know what the defaults are. Especially with mono recordings, the differences can be very, very subtle–I don’t always want to obsess over a difficult decision, I just want to relax and listen to what the engineer probably intended!
Both my preamp and power amp invert phase, so the final output to the speakers is in phase, and it sounds right with CDs that are listed as having normal phase. Thanks for any enlightenment–Kevin