Great post there! And I agree. Also there is the thought that some noise (tape hiss for example) can help us discern more detail and low level information. Don't ask me how, I just read that in various papers and some pro audio reviews.
But to me, my personal problem with this digititus thing as we are calling it is more simple than any of these things. It is a coarseness in the 10-15 Khz region. To break it down to descriptives, it sounds like a chain saw type noise as a recessed part of the details and some sibilance (very subtle but is there regardless). I have no real technical backup to prove this, but I wonder if it is caused by the digital filtering and / or up sampling? Hard hat donned for the blow back here! But anyway, that is my theory. The DACs I seem to relax with and enjoy the most (less stressful) seem to be the R-2R variants, and the ones I don't enjoy seem to be the DS variants. Huge caveat and I have not heard them all obviously, I am talking a round up of my demos.
Yes, I agree - with many SD DACs there seems to me to be a coarseness that sets in in the HF area when crescendos are being replayed - it's as if some auto gain control kicked in & things become too piercing -
the musical flow is interrupted. I'm sure it's a perceptual effect for something in the sound which we are picking up in this way - in other words trying to find an increase in gain in the HF would be a misdirected search.
This 'flow' to the music is one of the strengths of analogue but it's often overlooked until it's compared to digital.