Very interesting, all. Rob, I've been following your experimentation with various DACs with interest, and, well, my interest remains. I suspect, in the end, however, that we're all more in agreement than otherwise. Marketing hyperbole aside, I submit (surmise?) that there are really a limited amount of variables in play that can meaningfully differentiate one piece of gear from another when it comes to sophisticated, well-considered DAC implementation. When one gets to comparing the differences among the sort of gear that we're all so fascinated with, the bottom line is that the differences are really not going to be all that earth-shattering. Put differently, and as has been observed many times, were likely the obsessive few dealing with vanishingly diminishing returns between the 99th percentile (above which most folks never imagine to venture) and the 100th percentile of very-likely mythical true reproduction of recorded material.
All that said, I do not for a moment mean to diminish the relevance (or importance) of these small distinctions. They are, after all, what were all about. Although I am admittedly guilty of having limited experience on my own digital safari, I certainly identified and developed preferences among various digital sources. My reference for years has been a Meridian 508.24. Hardly the last word in anything, but a relatively (and enduringly) nice piece of kit. When I first sought to make the transfer to a computer-based system, spent a little over a year with a MHDT Havana as the DAC. Also nice, but in the end just didnt think it was in the same league as the Meridian. Warmth and bloom that I so chase after, yes, but clearly at the expense of resolving power, finer detail, and the more-complete sense of presence and recreation of space that these micro-details convey. Minor very minor distinguishing details, but on the whole details that convey a materially different experience. Ive also had in my system a less-expensive Taiwanese DAC (a friends, dont remember the make) that was significantly less impressive than the MHDT. Again, very minor details in the grander scheme of things, but the sum of the parts were materially less capable of conveying presence and the full experience. Following the day spent comparing the MHDT, the Meridian and the mystery DAC with said friend, I became obsessed with finding a more resolving DAC that could run with the Meridian and to me this entailed moving from the non-up-sampling offerings to something else.
With that, I found myself in a shootout between the Ayre QB-9 and a Bel Canto 3.5 at a local shop (mostly Bel Canto electronics, higher-end Totem speakers, running Amarra on a Mac for a source). Yes, somewhat arbitrary, and arbitrarily limited, but there you go. The Ayre and the Bel Canto were awfully similar, no mistake. Both portrayed a largely indistinguishable soundstage and level of detail and were quite impressive. Ultimately, to my ears on that day, in that room, on that equipment, the Bel Canto was slightly more etched and sharp in its presentation, while the Ayre was a touch warmer and more relaxed. A very minor difference, but a material one in my book. Ended up with a pleasantly-cheaper Ayre.
Since then, spent about a year running bit perfect (through Bit Perfect, which is great) in integer mode with no upsampling. Then I started to acquire more and more high res material. Recently, I have converted to a USB 2.0 feed and begun upsampling (by powers of two) to either 176 or 192khz, depending on the source resolution (44khz x4, 88khz x 2, or 96khz x 2). Fascinated by the flexibility this gives one to change really material stuff with only the ticking of a box (on Bit Perfect, did I mention I like that program?). Still not sure theres a clear preference often changes depending on the material but love the flexibility. The bits/transport end supplying what the DAC is fed makes a real difference. And absent a common language regarding that, I suspect that DAC comparisons may be at a real impasse. I will say, however, that the whole experience has severely damaged my belief that there is such a think as truth or a meaningful benchmark against which to objectively rate all comers. You can judge X against Y in-system and prefer one to the other, or not, but at least I dont seem capable of going much beyond that. And one can make and perceive changes, but conveying them to others through words, much less convincing anyone that one may be better than another, is so fundamentally context-based and subjective as to be nearly impossible. I will say, apropos of the original premise, that the difference between a $200 Kimber USB cable and the free one that came with my RAID drive especially running USB 2.0 is exactly zero. Usual caveats, my system, my room, my ears, but I stand by conclusively zero. (And this from a true believer that cabling elsewhere in the system makes surprisingly significant differences.)
(And if you really want to damage your calm, get ahold of some analyzing software and an SPL meter and run some hard data on your room performance. Ive had both a professional sound engineer and a world class ballet dancer graciously comment that I can generate some of the best sound theyve heard outside of a professional recording studio bless them both, does wonders for the ego but, let me tell you folks, my rooms a travesty. In the interest of moving from strategic wild ass guesswork (SWAG) to actual f-ing data (AFD), Ive seen the AFD and my rooms an unmitigated disaster. Makes quibbling about the finer points of DAC selection seems a total waste of time. Relativity and context is a bitch. Alas.)
Anyway, ramble aside, DACs have one thing going for them that no one can deny theyre likely more portable than just about anything else in this hobby. Ive got two (the Ayre and the Havana). Anyone in the NYC area interested in continuing the shoot-out? Cant make any promises, but I could be game....