My point, as more and more music are available in Hi-Res, I think NOS DAC will become popular again.
I removed the run-in to this final sentence because there were so many unfounded a priori conclusions in there that were in the Not Even Wrong category. You did invoke Nyquist however, and he was no dummy—although I own a DAC capable of the highest sampling rates and stream from hi res services, I’m under no delusion that this “hi res” obsession is anything but in large part illusory, because few of us (especially those over age 30) can detect anything close to 20,000hz, and you barely need much over 16 bit to resolve our empirically demonstrated 96dB dynamic range capacity. The only empirically demonstrated benefit of hi res formats is for mixing and mastering engineers and music catalog archivists.
Some of the fundamental purposes of oversampling DACs are to spread out or shape away quanitization noise from the audible range, and to push the noise floor into higher, inaudible frequency ranges above what we can detect—in other words to solve the problems you keep maintaining that oversampling causes.
There are a few NOS DACs, such as the Holo May, that perform comparably to DS DACs on the bench, but the majority we’ve tested here do not. There are some folks that seem to prefer NOS DACs because their flaws are experienced by them as “warmer” or “more natural”—although digital noise is pretty much established as unpleasant, and that warmth can be added at the amp stage through tubes, PEQ or modeling software in a much more satisfying, nuanced way.
The entire purpose of DACs is to recreate the sound of the original master as accurately as possible, not to cause errors and digital noise, or even warmth or colorization for that matter. That means reconstructing what was sampled with the lowest SNR, highest dynamic range and least distortion possible. Amir always gives his subjective opinion on which post-conversion filter sounds “best”, but I personally struggle to hear the differences among any of them and I’m not alone.
We’ve achieved the limits of what DACs can do functionally awhile ago—the SINAD differences we’ve been tossing around toppled the limits of transparency arguably before this site was founded. We’re mostly amused at this point by the pricey gear (including NOS or R2R ladder DACs) that barely manage to clear Red Book CDs in quality. So it’s highly unlikely that NOS DACs are going to make a comeback in the future, especially for masters with high sampling rates. That would be progress going in reverse.
DACs should be the least of your worries and your least costly expense at this state of the art. If you truly want to achieve the qualities you seem to aspire to, I’d suggest you redirect your energies on your headphones/speakers, DSPs, valves if you like, or even vinyl. If your goal is digital fidelity and precision however, just pick the cheapest of DACs on Amir’s top ten and you’re there. Most of what you’ve been parroting is marketing woo, and if there’s any concept that would take you the farthest on your journey from this site, it’s cognitive bias.