I have tested 'native' CD replay (from the built-in CD player) vs ALAC rip of the same CD using Airplay.
The test was as close as you can get. Same device with the same DAC and the same speakers and only a couple of seconds between comparisons (remotely switching between paused tracks on iMac iTunes and CD player in Marantz).
The results were as close as I could expect too.
Not sure I could hear any differences TBH.
Maybe it was because there were no intervening 'boxes' (like ATVs or AEXs) and no other DACs involved. Dunno. But i am happy that there was so little (if any) difference.
I am not an 'audiophile'. I don't measure the distance - to millimetre accuracy - between my ears and speakers and I don't sit in a special listening chair - with my face scrunched up in total concentration - noting the number of 'spontaneous foot taps' on a clipboard!
I don't even like the term 'audiophile' and never want to listen to music in the same room as one
I am not going to repeat the tests. Once was enough (just after getting the Marantz and AirPlay up and running a couple of years ago) and I felt like an idiot even then! Just wanted to re-assure myself that AirPlay sounded good enough to move over to it as a preferred way of listening.
YMMV and good luck to your golden ears (and tapping toes) if it does.
My last post on this thread.