preamp inverts polarity

"...except to check if "maybe" something is out of phase,.."

I don't think your ears will be able to tell the difference unless you have a "phase correct" reference you can compare with. I listen to a lot of the same music albums on both LPs and CDs and I occasional run into a CD/LP where I can easily\y tell the difference but it is more like the channels are reversed because both media sound good and nothing seems to be missing.

"Is "phase inversion" the same as "polarity inversion"?"

Good question.  

“why single ended amps best emulate the character of the medium sound travels through”

This is very intriguing. Does this have to do with how the electrons move to create voltage to drive the speakers or something else? Hard to connect the dots.

geoff, read their posts again...they said “ decompress” air not compress. Either way, you’re correct about how vacuum is obtained. 
I’m still stuck on that single ended amp remark...😁

OP, go back and read Almarg's post. Your original question was answered two and half weeks ago.

Trying to win an argument by insulting someone is a sure sign of losing the argument. 

Anyone interested in the subject should read The Wood Effect. Just received my copy and it covers the (polarity) subject more than I ever thought possible...