Imet Dusty Vawter, President of Channel Islands Audio (often abbreviated to CIAudio), on a shuttle- bus ride to the Denver airport as we returned home from the Rocky Mountain Audio Fest. Mr. Vawter, I learned, had been head of customer service at now-defunct Audio Alchemy before founding CIAudio, and the experience left him with a refreshingly different slant on high-end design. Like any serious manufacturer of audio products, he is passionate about sound quality, but more than many he believes components should offer solid buildquality and should be rigorously designed and tested to provide troublefree performance and reliability at sensible prices. Amen to that.
CIAudio offers a range of audio components that includes a family of Class D amplifiers, some of which I’d heard in speaker manufacturers’ demonstration suites at RMAF. CIAudio amplifiers are based on the comparatively new Philips/Hypex UcD (Universal class D) modules, rather than on the earlier Tripath or Bang & Olufsen/ICEpower technologies used in many other Class D designs. Like the NuForce amplifiers recently reviewed in TAS, the CIAudios are analog switching amplifiers, not “digital” amplifiers—an approach that proponents say gives Class D amps a more open and detailed sound. With the current proliferation of new Class D amplifiers on the market, many TAS readers (and writers) are curious to learn how the latest designs sound, and for this review we chose a pair of CIAudio’s newest model, the D-200 monoblocks. The D- 200s are small, cube-shaped units that deliver 200Wpc at 8 ohms and sell for $2299 per pair. At that price, the D- 200s offer two options: either 26 or 32dB of gain (the latter intended primarily for use with passive level-controls), and single-ended or balanced inputs.
Typically, Class D amplifiers are light, but the D-200s weigh in at a comparatively chunky 15 pounds apiece— heft that reflects both a beefy chassis on the outside and an even beefier powersupply on the inside. Early on, I discovered the CIAudio amps, in contrast to the NuForce Reference 9s, were utterly quirk-free. There were no power-on “pops,” no subtle increases in background noise with muted inputs, and— says CIAudio—no sensitivities to noload or dead-short conditions. Vawter has zero tolerance for finicky products. The D-200s also offer a feature I came to love: a play/mute switch in lieu of a traditional power switch. This feature enables users to keep the amplifiers warmed up and ready to play, while allowing output muting when switching associated preamps on or off. At Vawter’s suggestion, I gave the D-200s about 100 hours of burn-in before listening critically, and during burn-in observed small, gradual improvements in bass solidity, midrange smoothness, and treble resolution.
When I review components, I try to identify their dominant sonic characteristics, and what first struck me about the D-200s was the sweetness and delicacy of their midrange, the warmth and quickness of their midbass, and an overall presentation that, paradoxically, sounded at once detailed yet very smooth—almost to the point of sonic politeness.
To zoom in: The midrange sweetness is the sort that makes both male and female voices sound graceful and rich, even if some rough edges are ever so slightly smoothed out in the process. A good example is Dave Alvin’s voice on “California Snow” from Blackjack David [MFSL SACD]; Alvin’s dark, smoky, storyteller’s voice comes through vividly, but with its typical gritty and gravelly textures planed down just a bit. Similarly, the D-200’s midrange makes strings in general and solo violins in particular sound achingly beautiful, albeit with their uppermost harmonics and the inner textures of bowing and finger changes diffused just a little. Listen to the Heifetz performance of the Sibelius Violin Concerto [RCA Living Stereo, SACD] through the D-200s, and see if you aren’t flat bowled over by the glory of Heifetz’s string tone.
Still, the question of the D-200s’ handling of high-frequency details and textures remains. My observation was that the amps reproduce low-level details well up to a point, and that their high-frequency response is not rolled off. However, as high-frequency details
become progressively finer and subtler, the D-200s eventually allow their contours to melt into a soft diffuseness—the sonic equivalent of a cinematic dissolve to white. In fairness, I should say this blurring affects only the very-lowestlevel details, but when it occurs, key ingredients of transparency and of great soundstaging are, to some degree, lost. This leaves me of two minds. On the one hand, the D-200s are never guilty of the sort of overwrought transient excesses that drive many of us nuts, which is a very good thing. On the other, they fall short of the profound transparency and three-dimensionality that amplifiers such as the NuForce Reference 9s offer.
The D-200s’ midbass is pleasingly warm and weighty, with a good measure of transient snap that helps make basses (acoustic, electric, and human) and low percussion instruments sound articulate and expressive. Listeners will particularly appreciate these qualities on recordings such as bassist Charlie Haden’s Nocturnes [Verve], where the ever-tasteful Haden makes his musical points not through flashy pyrotechnics, but through delicate variations in the attack, sustain, and voicing of his well-chosen notes. Overall, I found the D-200s offered midbass clarity on a par with that of the considerably more powerful and expensive Audio Research 300.2 power amplifier and Musical Fidelity kW500 integrated that I had on hand for comparison. Alongside the NuForce Reference 9s, the D-200s delivered slightly warmer and more prominent midbass, while the Reference 9s offered more potent and extended low bass and an even greater degree of overall bass control and definition.
Finally, the D-200s sound unfailingly smooth, even on complicated, densely layered material such as
Respighi’s Pina di Roma [Deutsche Grammophon, LP], which can make some components sound frazzled or distressed. Provided you don’t crank the D- 200s to levels where they start to run out of power (something I’d not recommend with this or any amplifier), they’ll sound graceful and self-assured. But this selfassurance carries, I think, a small but audible sonic price, namely, a tendency toward sonic “politeness” that—in a very subtle way—softens the vividness and liveliness of reproduced music. It’s not that the Channel Islands amplifiers sound dull or compressed; they don’t. In fact, the D-200s sound very expressive in comparison to well-regarded traditional linear amplifiers such as the current generation McCormacks. It’s just that there is an elusive layer of dynamic accuracy, or intensity if you will, that the D-200s can’t quite reach. After you play a selection of reference recordings on the D-200s, the first word that would come to mind might be “smooth.” After you hear the same selection on the NuForce Reference 9s, the one-word description might change to “alive.”
The Channel Islands Audio D-200s are very good amplifiers, and they show every sign of being a polished, thoroughly tested, trouble-free design (would that every high-end manufacturer took product reliability and testing as seriously as Channel Island does). The CIAudios earn high marks sonically, as well, sounding noticeably better than many old-school linear amplifiers and offering sound that is on a par with that of contemporary Class D amps such as the Audio Research 300.2. But the D- 200s’ most direct competitors are the NuForce Reference 9s, and a comparison forces the issue. The fact is that the D- 200s sound very good and have no vices whatsoever, while the slightly more costly Reference 9s offer elements of true sonic greatness, but at the expense of some annoying quirks and foibles. The sonic differences between the amplifiers are such that I could imagine listeners choosing one or the other purely as a matter of taste, and both offer exceptional value for money. If you like amplifiers that combine detail, smoothness, warmth, and clarity, then the D-200s could be perfect for you; but for greater overall transparency and three-dimensionality, and more lifelike dynamics, the Reference 9 would get my nod.