Very non scientific, lol. Just quick n dirty. I had Amazon Music and Foobar2000 open and playing the same song at the same time code. I let one play for a few seconds, then pause it and hit play on the other and listen to the exact same section of music. If anything I would have expected the "superior" Amazon source to sound better (if there was any difference at all). The sources were not level matched and everything was controlled by me so flawed for sure.