As an aside, WHY did Sony/Philips settle on a 2V output? I mean, with a passive style of output level, this is about the same as vintage tuners and tape decks.......
Higher voltage = higher output = more apparent detail in the music.
It's the reason why you have to be so fastidious about level matching when comparing source A with source B - the louder source will always seem to have greater detail retrieval.