I listened last night to K.D. Lang's Hymns of the 49th Parallel on Amazon HD - the entire album is at 24-bit/192kHz. I varied the volume up and down 10db via either the Atom or the D50S - could not hear a difference through my Etymotic ER4S IEM. I've since reduced the Atom's gain to 12 0'clock and upped the volume on the D50S and will leave it like that for a week and then reverse it again and see if I can tell any long term difference.
I would't bet on it...
I would't bet on it...