Shadorne’s technical points and the statements in the video he linked to all make sense to me, at least theoretically, as does the response by Mmeysarosh.
FWIW, though, I took a close look at Figures 6 and 7 in
JA’s measurements of the Yggdrasil, which show the responses to undithered 16 bit and 24 bit signals at very low levels of 90.31 db below full scale. The bottom line is that the response to 24 bits looks vastly better than the response to 16 bits, and looks quite good aside from glitches occurring at the zero-crossings. And for that matter a comparison of the 24 bit response shown in Figure 7 with the corresponding Figure 12 for the comparably priced
Mytek Brooklyn DAC (and its 32 bit converter!) shows the Yggy looking at least as good and probably better, aside from the zero-crossing glitches. Even though JA described that output of the Mytek as being "a well-formed sinewave," and its overall measured performance as being "superb."
And regarding the zero-crossing glitches, those likely reflect what we’ve previously presumed to be the switchover between the two DAC chips that are used on each channel, that would occur at the zero-crossing, and they would therefore be unrelated to truncation error or rounding error. And given that the glitches are more than 100 db below full scale and are very short in duration they would seem likely to be audibly insignificant.
FWIW. Regards,
-- Al