I found this statement from John Atkinson (the one that measurement obsessed folk fall back on for support) to put a kibosh on most A/B/X tests:
All the best,
Nonoise
...2nd order behaviors -eg-distortion signatures and noise modulations that characterize sound quality, and these things take a lot of listening to identify.It's what I and others have repeatedly stated: long term listening is the correct way to identify sound signatures and clues. You can get the gist of a cable or fuse or what have you but it takes immersion in the music, over time, to correctly assess anything, unless it's something glaringly apparent.
All the best,
Nonoise