@agentwja
You write of the possibility of getting an R2R DAC and a chip DAC to compare. If you look around you can see that it’s been done here by two fair and credible audiophiles with no commercial interest in either. Moreover it was done with two very different audio systems and (probably) with two very different choices of music. That would be by @pt999 in this very thread comparing the Musetic with dual ESS9038pro chips and the Holo Audio May KTE. The other is by by @dbb in the thread, https://forum.audiogon.com/discussions/review-holo-may-l2-dac-and-the-musetec-audio-lks-audio-mh-da005-da, comparing the Musetec with the Holo Audio May L2 DAC. Despite their personal differences, they came to very similar conclusions, to wit, these DACs are very close in performance. I’d like to speculate why that might be.
There is a great effort by the industry to promote the differing technologies in the digital realm. Whether they promote the R2R technology, the ESS9038pro or other chips or the chips they develop themselves using FPGA chips. Two of these technologies are relatively expensive to produce. That would be today’s R2R technology and the FPGA chips.
The R2R technology of today is a discrete one. It is made of many individual parts, including lots of precision resisters. In parts and labor, that is expensive. Some time ago R2R chips were easily available so all of these parts and this labor were collapsed onto a relatively inexpensive chip. And in the digital realm, it seems, chips work as well as discrete. But these chips are no more, but for some NOS.
Programming an FPGA chip is an alternative to paying anywhere from $20 to $95 (in small quantities) to companies like TI, AKM or ESS for their chips. It takes many man-hours to do it. That costs money. Whether the result can outperform the three decades and three generations of ESS chip development, for example, is a question that has not been answered, for me anyway. But it does give companies that do it the promotional possibility of differentiating their product. "Our chip is better, like no other, and it can be updated!"
All of which leads to my personal conclusion that none of this matters as much as the more important considerations of a DAC. Makers who purchase the relatively inexpensive chips can put their resources here. They are: (1) Power supply and (2) analog section. There are some very well known and very expensive DACs that use cheap power supplies. There are some very expensive and very well known DACs that use cheap analog chips as the basis for their analog section. IMO one of the reasons that the DACs in the two comparisons above sounded both very good and very much like each other is that they both have fine power supply sections and fine discrete analog sections.
How can you tell when a DAC has a good power supply and/or a good analog section? You must look inside and see. Or find a review that does that for you, rather than just recite a list of audiophile platitudes and call that a review.
I’m not here to denigrate any brand, but two you list have been around for a very long while and one of them, at least, is well known to have a sound signature particular to the brand. Also, look inside and compare. This is a fast moving segment.