preamp inverts polarity

Absolute phase and polarity are the same thing.
Relative phase is one channel out of phase with the other and should be corrected, regardless of the absolute phase/polarity (IOW, whether your system is inverting or not).
I rarely agree with Geoff on anything, but in the case of recordings he is correct. The recording industry doesn't care about absolute polarity; 50% of all recordings are inverted polarity.
We have a switch on our preamp to correct this if needed. That's a lot easier than swapping the speaker cable polarity in both channels to see if its better or not.
Absolute polarity can usually only be heard if the recording is done with just two mics (possibly also with a third center channel mic mixed in). If more than that, the signal gets too messed up and you simply can't tell.

atmasphere, you should agree with me more often. You’ll be much better off in the long run. 🏃

To be a little picky, I have been saying for CDs the percentage might be much higher than 50%. In fact, if you believe G Louis, the Polarity Pundit, the percetage is 92%.  That’s why I’ve pointed out a number of times recently, i.e., the last few years, putting one’s system in Reverse Absolute Polarity might actually be the best long term strategy. What with overly aggressive compression and the absolute Polarity issue CDs have devolved from perfect sound forever to perfectly atrocious.

I don't believe G Louis. He came into our room at CES once, insisting that the polarity was off in our system without even sitting down to make his revelation. I flipped the switch (which has been a part of the MP-1 preamp circuit since its inception). At that point he said it was only audible on CD- not LP (which was the second sign of baloney).
I had the same cut on CD and played it- he didn't see that one coming... At that point he insisted that if it was recorded analog, but encoded to CD, you couldn't hear it. What nonsense.

The thing was, it sounded better the way we had it. The recording in question was done with two mics (Canto General). He made a hurried exit, apparently aware he had embarrassed himself.

50% is about right. Mastering engineers are not worried about whether their equipment inverts polarity or not. So its just statistics.

Atmasphere, after listening to your explanation I’m even more inclined to believe G Louis. Two microphones or one, doesn’t matter, or three microphones. I also believe him when he states most audiophile recordings, even such famous ones as Mercury Living Presence and RCA Living Stereo, are in Reverse Polarity. You can squawk all you like.