I have a Cary SLP-98L and the manual specifically states to make the switch at the amp end. As for hearing a difference quality wise I don't know about that. I do know that on the live recordings I have made and play on my system that when the phase was not inverted the sound was off balance which makes sense.
Inverted phase preamps?
What is the best way to adjust for this in your system? Could you give a detailed view of what you reccomend, for example: reverse speaker wires at the amp?,etc. I have heard different ideas from some reputable people. I know that it comes down to what sounds the best, but I would be very interested in hearing your experience with this. Thanks.