I saw nothing more there for that FR plot. If I would have to plot a DAC outputs frequency range (for RCA or XLR), I would use any high sample rate like 192k or more. It shall so not be flat up to 88.2k-100k, but limited, depending on the output stage and line load (line/output buffering capabilities).
Somehow Amir plots this, partially and for the audible band, when he cheks DAC linearity from 0 to 20k, using 44.1k.
About those pops (and later also smaller crackles in that same Hush track), you shall get them, as I get them here, even on basic speakers (not on my laptop mini speakers, but they are very limited).
Maybe you listen differently than I do? Especially for such a track, you do not like? I'm sensitive to any clics, pops or noises, even smaller ones. Whatever the general track quality is. Those I hear in that Hush track don't seem to be part of the artistic project, that is the point, so they are/seem disturbing to me.
Listening the way I do, I noticed I was sometime getting additionnal noises with my D50s setup, noises not being in tracks. D50s setup: not only the DAC, but PC, amp, DAC and DAC PSU. I cleaned up my groundings (potential source of EMC/mains noise), my USB VBUS, and moved away my phone (high power and RF signals too close to DAC/RCA wires).
For pops in Hush track, one could use the D.zip attachement I added here, will be easier:
https://www.audiosciencereview.com/...-khadas-tone-board-1.24596/page-8#post-833718
- the Original, with the 47" shape/pop (not so loud, but can be distinguished)
- the Different file, in which I aplied EQ to the track, but only on that pop
- the track shape is different in EQed file, at some part, see below picture
- looping them with Audacity, the Original shall sound different, poping at around 2"280...