Why most $3000 and lower DAC’s sound almost identical

The OP raises a lot of detail that may indeed be relevant. But as is the case so often in audiophilia, the issue is not whether an effect merely exists, but whether it’s significant enough to be audible. IOW, an argument like this is credible only if it establishes quantitative, not merely qualitative, support. 

I realize that that’s not easy in our field, where even testing methodologies are hotly contested. Having said that, I do offer a counterexample that may add another wrinkle to the issue. I realize that I’m merely making an inference. But it is an inference that is worth considering and is apparently supported by empirical data generated by some of the world’s most respected DAC designers.

T+A, one of Europe's ’s most highly regarded manufacturers of high-end DACs (well-known on the continent and now starting to establish a rep in the US) sells sophisticated $5-9000 dual-path DACs that process PCM with Delta-Sigma circuitry, but run DSD through an independent bespoke R2R DAC. 

The only reason I can think of for this complex design is that T+A engineers confirmed that, within the context of their design methodologies, each topology produced better results with one type of content. I doubt that this solution was adopted for reasons of cost or complexity. 

That suggests that the DS v. R2R controversy can’t be resolved conclusively by focusing on one, or even just a few, isolated factors. That is, "R2R is better across-the-board than DS in a certain price range." is too reductive, too conclusory, too Wikipedia/ChatGPT, to make me run out and replace my T+A (which, FWIW, is the best four-figure DAC I’ve heard. Check out Stereophile’s R 2500 R review, in which Tom Fine compares a stripped-down embedded version against his $20K reference DAC.)

Nonetheless, the OP does raise interesting issues. Interesting enough, in fact, to make me want to go out and further research the topic. Thanks for starting this thread.

I’ll have to check out that Holo DAC.  Sounds interesting.  Any technical papers you’re aware of that detail what’s under the hood?

One thing that continues to amaze me is the lack of T+A awareness among street-level audiophiles.  See, e.g., this thread itself.  One reason might be T+A’s low profile at American shows.  I was speaking to a colleague who visited two AXPONA booths that featured T+A gear last month, and he reported that neither setup produced SQ anywhere near what I hear at home from my T+A integrated, which is the sole source driving a pair of Harbeths through mid-fi (like $1K) cables.

@shadorne 

I started out as a test engineer in the late 1970s and remember using, I think it was called, an Audio Precision System One, the standard high-end signal analyzer at the time, and probably the predecessor of the type of device you’re referring to as  Precision Analyzer products.

I remember that even back then, those analyzers could operate in both the frequency and time domain.  I even remember using our System One to perform Fourier transforms.

So I’m not sure about the "sad truth" you cite re:Precision Analyzer’s current product line operating in only the fr domain.  I could certainly make the kind of measurements you describe with a pro signal analyzer 50 years ago.  In fact, I half-remember someone like Atkinson routinely publishing such measurements years ago in the slick audiophile press (although I may be misremembering after all this time).

To be clear: I’m not trying to start a debate.  Just hoping to learn something about the current state of an art (of great interest to me) that I haven’t followed since retiring.

Hey, thanks for the Holo/Stereophile link.  I sorta recall reading that piece years ago, but will take another look, given the new context of this thread.  Not sure how much of the articles conclusions still hold up half a decade later, but I'll check it out.

@mapman  Don’t hate me, but if you’re looking to get defiitive buying recommendations from an authoritative source, IMHO, Audiogon is not the place.  The value of this thread, e.g., is its discussion of under-the-hood D/A tech, which as I’m sure you know, doesn’t necessarily tell you anything definitive about SQ.  The idea, I think, is that, if this thread increases your understanding of a technical issue, you’ll be able to ask more educated questions when you go shopping.  IMHO, that’s a heckuva lot more valuable than plowing through dozens of "I really like this DAC!" messages from strangers who use a product with systems, rooms, cables, and power that may be nothing like yours.  

Over the years, I’ve found that the real value of fora like Audiogon -- other than providing a platform for masturbatory proclamations of conclusory opinions -- is more along the lines of "Teach a man to fish...".  My 2c.

Jeez, wouldn’t "MPoCO" be a great name for a band?