Word on the street had it that the first batch of Opus 21 CD/ROM drives exhibited audible whirring or whining noise. It still makes a very faint spinning sound but you'd have to be within one foot from the unit and with your ears on the level to make it out. It's not a steady-state but rather on/off-type flutter that's completely inaudible from average listening distances or even from up close once you leave mute and have music playing. Think very mild transformer hum that might cause theoretical arguments but zero practical implications. I had to listen for it to detect it and personally wasn't at all bothered. The only item that bothered me a little was the strange absence of the usual time|remain display functions. I occasionally like to record compilations for friends to introduce them to new music. I then always use the track|remain readout to be on alert and prepare to pause the recorder for the next CD and track when the current track is about to expire. This is probably a convenience feature of precious little relevance to regular listeners but I was still surprised to see it omitted on a $3,500 machine. On the distinct upside of this minor gripe ledger is the four-tone palette of available front panel options - all black, all silver, black/silver or silver/black. This is yet another reminder about how Jeffrey Kalt deliberately caters to decor-conscious sensibilities. Yes, this approach does not extend to a snazzy metal remote. But that's repeatedly an attribute of small-volume speciality manufacturers. They can't assimilate the tooling and coding costs for a custom metal wand without upsetting their anticipated selling price.


My resident $2,500 Cairn Fog one-box player with 24/192 upsampler card recently and inexplicably started to distort in the right channel, both via its digital and analog outputs. A driver or chip seems to have gotten whacked by some aggressive soprano. Lacking this sane comparator for the Resolution player, I would have to rely on the $15,000 combo of Ensemble Dirondo/Dichrono for context. That admittedly would be anything but sane but still useful to report on how much the Opus 21 might leave on the table when being compared to a cost-no-issue effort. With the present level of maturation in the RedBook medium, the bulk of the available performance has consistently pressed downwards in price. This gives far costlier players less and less concrete sonic advantages outside of truly high-resolution contexts. Those can magnify these more subliminal strata to degrees that make -- or seem to make -- such smaller differences justifiable to deeply committed audiophiles. At $3,500, the Opus 21 is middle-of-the-road in our perverse little world. But what if its performance could capture 90-95% of ne-plus-ultra glory? Said perversion would suddenly seem far more palatable, yes?

If you were to call a decidedly un-edgy, anti-brittle, non-dry digital presentation voiced, then the Opus 21 is very cannily voiced indeed. It's all 1s and 0s? Not. The analog output stage and power supplies in CD players leave plenty of room for a gifted designer to tweak for sound and texture. Having heard both the CD-50 and CD-55 (I preferred the earlier model by a small margin), I am reasonably confident that the Opus 21 exhibits a distinct family resemblance. It's got a slightly wet texture that's quite different from the drier, somewhat more cerebral sound of the Ensemble. The treble in particular deserves mention for completely lacking that peculiar and stand-offish dry, thin and somewhat chalky quality that often accompanies digital. Combined with this subtle sweetness comes an overall sense of density to instrumental and vocal images that enjoys parallels in how tubes and transistor amps tend to differ when projecting and outlining an image. The former are often articulated denser but feature softer, more feathered edges for a sense of roundness or fullness. The latter can be sharper and more incisive but also leaner, appearing perhaps faster but also dimensionally flatter.


Naturally, all these segregationist lines 'in the sand' blur nowadays. When generalized, such descriptions are usually found wanting. Anyone citing one of the many possible exceptions can blow huge holes into them. Still, for the purposes of descriptive verbiage, they do serve a purpose. They steer you in the right direction of getting a sense for the Opus 21's sound. By comparison, the Ensemble separates combo, especially when run in 96kHz mode at the transport and not the DAC, was slightly more acute and resolved when it came to spatial micro details of hall ambience but the Resolution player in its gestalt reminded me more of my Zanden DAC. Like the treble which attracts attention for not attracting attention, the bass is utterly devoid of that hyper-chiseled, unnaturally massive mien which sometimes wins over folks who hear a new power cord or cable or active electronics piece that seems to add a subwoofer to their prior setup.
That's impressive in the short term but unnatural in the long. The Opus 21 avoids any such shenanigans. Like the remainder of the spectrum, the bass is agile and natural yet touched by the same very becoming texture. That's a bit reminiscent of tubes. Don't misunderstand, I'm not talking any THD-related timbral or tonal effects. I'm sure that harmonic distortion measurements would show no such thing. No, I simply mean a particular combination of density and wetness that's subtle, naturally, but clear by comparison to the Ensemble which is drier, perhaps more neutral in that sense but not quite as pleasing to a tube guy like me. How Herr Kalt managed that with a name like his -- "kalt" is "cold" in German -- I have no idea but the fact is, this is a player that's modestly warm and round without at all seeming to be slow, thick, ponderous or opaque.


That's quite a mean trick at a time when so much about so-called digital evolution revolves around processing speeds, bit rates and word lengths; when resolution and detail retrieval seem like ultimate deals to pursue. Compared to the Ensemble separates, the Opus 21 takes a tiny backwards step in apparent resolution. Spatial details don't seem as obvious, the textural fabric of the music compacts a bit. You could say that the Ensemble wins if that's where you're coming from. But where I'm coming from, the Resolution Audio player actually speaks stronger to my pleasure center and would thus be my preference not as a reviewer's tool but music lover's device. That doesn't make it better per se but is indicative of how resolution and so-called neutrality aren't the only goals worth pursuing. It all depends on your priorities.


I was beginning to think at this point that what I was hearing had to be a pretty stonkin' preamp section. The Ensemble Dichrono HiDac can also be used amp-direct as an integrated DAC/preamp whose volume is attenuated by a motor-driven pot rather than digitally actuated chip. I don't like it that way. It leans and flattens out what already is a cooler,' brainier' presentation to begin with. Despite the apparently redundant complexity of an additional pair of interconnects and further active circuitry, my Bel Canto PRe2 is distinctly preferable. I quickly returned to using the Dichrono in fixed-gain mode. How would the Opus 21 acquit itself when removing the PRe2 from the picture?


Before finding out, the famous figurative lightning struck. Two other machines that approached or simulated the sound of my Zanden with its patented tubed output stage were the Audio Magic Stealth Kukama DAC and the universal Bel Canto Design PLayer PL-1A. Both implement proprietary passive I/V conversion stages which eschew op-amps even as lauded as the OPA 627. From my time many years ago, in California and with the Resolution Audio CD50 and CD55 machines, I remembered that they used passive I/V conversion as well. With very high probability, this had to mean the Opus 21 did too. Unfortunately, the Resolution Audio website seems deliberately coy about details. They refer obliquely to "new techniques for stunning performance". I wouldn't learn the full scoop until Jeffrey Kalt returned from his present business trip.
Confirmation or corrections would have to wait for a manufacturer reply. Still, I was pretty certain by now. The avoidance of op-amps might explain the very non-digital treble; the very faint reduction of ultimate resolution when compared to the Ensemble (indicating a slightly higher noise floor); but most importantly, the warmer, rounder, slightly luminous quality of textures which completely obliterate the drier, less involving and inorganic nature of digital in general. [Check out this link on "digital stress" provided by our own Les Turoczi. A holistic doctor talks about the therapeutic power of music, advanced muscle testing and how analog and PCM digital have opposing effects when used for healing/relaxing purposes.]


Time to spin more CDs. Incidentally, the CD/ROM drive used by Resolution Audio is positively rapid in accessing individual tracks from stand-still once the TOC has been scanned. That does take a few seconds but track access thereafter comes as close to instantaneous as I've seen yet. What's more, the remote has excellent off-axis dispersion to make aiming in the general direction all that's necessary to elicit prompt and reliable responses. The display dim/mute functions are a welcome feature as well since unattenuated and sitting within 15 feet from the player, the oversized blue characters are very bright yet perfect for far-field installations [see upper image, taken at night and with the display at full boogie].