When it comes to tube electronics few high-end companies speak as authoritatively and have been as honored as the Audio Research Corporation. On a far more personal note is the memory of a system I regularly enjoyed thirty years ago at a friend’s home–an ARC SP3a preamp and D150 power amp driving Magneplanar Tympani 1Ds, which had speed and transparency on a scale that gives me goosebumps to this day. ARC’s solid-state line, on the other hand, while highly respected has not been recipient of the kind of reverence reserved for its tube offerings. However, ARC’s latest, the new DSi200 integrated amp, makes a stronger case than ever. It’s a solid-state design with a secret.
From any point of view, the look of the DSi200 is pure Audio Research—from its classic squared line, to the heavy front panel and chunky grab handles. Large volume and input selectors flank a vacuum-fluorescent display whose brightness has six levels of adjustment. Beneath the display are four aluminum buttons for power on/off, mono/stereo, inverting phase, and muting output. These same functions, as well as a balance control and display adjustments, are also provided by a full-function remote control. The back panel sports three single-ended inputs and a pair of balanced inputs—their mirror-like, symmetrical layout exposing the dual-mono design of the amp’s circuit. The DSi200 is also available with a black front panel, handles, and knobs, but the chassis and wraparound cover are only be available in silver.
The aforementioned secret is the DSi200’s solid-state-hybrid design. It combines a hefty regulated analog linear power supply with a discrete MOSFET-based high-speed switching output stage of ARC’s own invention. While this implementation is not unique, ARC points out that, unlike virtually all other switching amplifiers, the DSi200 does not rely on any OEM modules or pre-manufactured components. The resulting amplifier outputs 200Wpc continuous into 8 ohms (300W into 4 ohms) with very high efficiency energy conversion—over 90%. Typical of this class of amp, the DSi200 runs very cool and because it draws only a scintilla of power at idle it garnered an “Energy Star” rating
I had the DSi200 powered up for only a few minutes when it became plain how authoritatively it reproduced music, particularly the lower mids and bass. Its ease and realism with pitch and timbre in the “nether regions” were superb. However, my broader impression was that the upper mids and treble range seemed out of character for an Audio Research component—they were a bit congested and tightly wound, and not playing ball with the mids. Since ARC is straightforward in stating that a significant amount of break-in time is required before the DSi200 settles in, I realized I would be remiss in not taking this caveat seriously. Long story short: I left the amp powered up cycling through the blips, ticks, and bumps of an Isotek burn-in disc for about a week straight without doing any serious listening. And the envelope please…
The difference was actually quite astonishing. Like a singer clearing her throat, the voice of the amp seemed to drop into a deeper more grounded place as if finally breathing from its diaphragm. It shed its papery thinness and smoothed out, like someone evening the wrinkles from fine bed linen. Violin, cello, dreadnought acoustic guitar, and even mandolin began resonating more fully and deeply. The DSi200 does not communicate an overtly sweet character in the sense of a darkened ripened treble, but neither does any astringency sour the top octaves. When I listen to violinist Arturo Delmoni play the “Allemande” from the Bach Partita No. 2 [Water Lily], I hear a sound that is neither shaded or spot-lit—just a marvelous sense of movement and action beyond the confines of the instrument itself. In this instance, there’s the thicker sound and increased body of the instrument coming into focus as Delmoni leans on the bow, digging into the strings for more volume and color. The ARC also reveals the air and open space looming behind the player, adding to the acoustic backbone of the performance. It individuates images and timbres with ease while also reproducing the interplay of textures within the soaring wind section during the playful allegro molto of Copland’s Third Symphony [Reference Recordings]. The stabs of brass, bass drum, and cascades of tympani during “Fanfare for the Common Man” were nothing less than electric. The DSi200’s grip on low-frequency pitches and timbres is steadfast; electric bass, kick drums, low percussion never lag or blur. Bass response is not overpowering but fast on its feet, allowing an acoustic bass to exhibit both volume and pace, not an easy act to balance. When it comes to midbass oomph, the DSi200 just seems to pull reserves from a seemingly bottomless well and yet never seems short of control even while driving demanding loads like the Magico V2 or TAD CR-1 loudspeakers.
This amp’s strongest suit is, far and away, imaging. Images are uncommonly specific and stable. The resolution of low-level inner voices and harmonies will keep you on the edge of your seat, as you uncover heretofore buried information. And it deftly negotiates complex orchestral passages—the second movement from Brahms’ Symphony No. 4 [DG/Esoteric], for example—drawing boundaries, defining groupings. And in spite of its excellence tracking the subtle cues and quirks of individual players, I never felt it deemphasized the totality of the performance.
Followers of ARC tube efforts will be wondering how the DSi200 measures up against its prized valve rigs. Certainly the extent to which you embrace the sonics of the ARC hybrid will depend on your expectations. Which is to say, if you were expecting the DSi to sound like an ARC 610T, or like tubes in general, you may be disappointed. In a way, its personality goes to the heart of the divide between tubes and other output devices. Its sonics do possess a glimmer of midrange warmth—of that there’s no doubt. But if you take, for example, a tube integrated amp like Tim de Paravacini’s estimable EAR 834, the EAR will charm you senseless with its warmer mids and liquid top end—and a soothing quality that solid-state still doesn’t quite capture. But then there’s the ARC’s tight-fisted grip in the bottom end. And the way it plays the inside game of audio with beautifully graduated microdynamics. It has an instantaneous reaction time—it jumps on dynamics. If it can’t quite impart the same level of air and sensuous intimacy as its own tube brethren, it has its own level of physicality and power that is equally compelling.
So if you’re willing to engage the DSi on its own terms, then you’ll realize it is its own unique animal. On a disc like Rosanne Cash’s Black Cadillac [Capitol], the transient speed of flat-picked acoustic guitars is so blazingly fast you can almost feel the sting of the pick radiating down your own wrist. Cash’s vocals are beautifully focused; electric bass is tuneful and precise. Speaking of which, the ARC communicates the surface reverberation of drums in such a way that constantly reminded me of the spring of a trampoline as I listened to Jennifer Warnes’ “Way Down Deep” on The Hunter [Private].
However its replication of soundstage depth is decidedly mid-pack. True, it does an excellent job delineating individual images and sections of instruments, but when it comes to deep soundstage space it reaches a threshold that in my room is about two-thirds of the way to the wall behind the speakers but generally no further. And in spite of its neutrality, I still find massed strings a bit lacking in buoyancy, as if the amp focuses more strongly on the transient entrance of a note, that note’s edge information, and a pinch less on its residual bloom and the duration of its decay.
Given the hybrid nature of the DSi200, I’ve reflected on our survey of Class D amplifiers published a few years ago (Issue 168). In that article the editorial staff, having listened to a cross-section of amplifiers, came to similar conclusions—that while the amps tended to have superior bass response, slam, and control, their top ends seemed less resolved and shaded, and dynamically a bit lifeless. Whether they were ready for “prime time” became a subject of some controversy—and amongst the staff, not too many hearts were set aflutter. The point here is that the DSi200 is at least a couple generations removed from that world and deserves to be assessed and ranked with the most competitive amplifiers in its segment, regardless of class.
The DSi200 sonically stands its ground with the cream-of-the-crop in high-power integrated amplifiers. And I’m talking about efforts from the likes of Pass Labs, Magnum Dynalab, Simaudio, and Plinius. ARC deserves to be commended for wading into the controversial waters that roil around Class D amplification—a potentially thankless course for a company so strongly associated with tubes. But inspiration and a lot of engineering elbow-grease have produced a terrific integrated amp, comfortable in virtually every sonic environment and priced aggressively. ARC’s new powerhouse is a cool surprise from the company known for turning up the heat.
SPECS & PRICING
Power output: 200Wpc into 8 ohms, 300Wpc into 4 ohms
Inputs: Two balanced, three unbalanced
Dimensions: 19" x 5.25" x 14.25"
Weight: 37.2 lbs
Audio Research Corporation
3900 Annapolis Lane North
Plymouth, Minnesota 55447
ARC’s Dave Gordon Talks About The DSi200
Did you have any uncertainties about developing a switching amp?
Our uncertainty was whether we could produce a switching amp that would not sound like other Class D amplifiers and not be a “me too” product. Could we produce a switching amplifier that sounded like a great Audio Research amplifier?
Were you concerned with overcoming some negative general impressions in the audio press and on the blogs about Class D?
Definitely. We knew that some people would be skeptical, dismiss it, and assume that it sounded like other Class D amplifiers—very difficult preconceptions to overcome, but that was our challenge. After the design was finished I took a preproduction DSi200 to a number of our retailers and demonstrated it in their best systems to prove that it defied classification and was simply a great-sounding product. The actual performance of the DSi200 had to dissolve any negative preconceptions, and it did.
Going in, what were the general strengths and weaknesses regarding the sound of this type of amplification?
Some of the strengths were low power consumption, high damping factor, low distortion, and a fast transient response. We heard several weaknesses including a lack of dynamic slam, an inability to really open up and play a lifelike, holographic (very wide and deep) soundstage, and some tonal anomalies.
How did you address them?
We started from scratch and did not follow others. We decided against using a pre-manufactured (OEM) module, so we designed our own discrete, high-speed analog output stage. Instead of using a switching power supply we designed a large, regulated, linear analog power supply like the ones found in the best non-switching amps. Then we paid a lot of attention to the input and output filters, parts materials, and to the quality of the individual parts. And, of course, we did a few other things that are confidential.
Was there a particular aspect to the design that surprised you in terms of its impact on the overall sound?
There were a number of things, but probably most surprising was how very critical the designs of the input and output filters were to the sound.
Was the goal to impart the ARC sound to the DSi 200, and to what extent do you think you succeeded?
We always used the performance of our Reference amplifiers as our yardstick, and the DSi200 sounds like an Audio Research amplifier. It exceeded our expectations, so we consider it a great success. Despite its relatively modest cost, we believe that the DSi200 will provide wonderful results with the finest loudspeakers on the market. (Don’t forget, KEF used the CD5 and DSi200 to drive its Concept Blade at CES, with great results.)
How important was it for ARC to achieve the Energy Star rating?
Achieving the Energy Star certification was important but not necessary. It was important because consumers are quite aware of it, and the certification is the simplest and clearest way to let everyone know that the DSi200 is a very energy efficient amplifier. (FYI, the DS450 also received Energy Star certification.)
Do you envision wider-range implications for the high end in general?
It depends what you mean; generally we are not sure. Worldwide there is increasing demand for high-efficiency products and more consumers are searching them out. In the high end, we expect that more manufacturers will introduce energy-efficient amplifiers, especially as the residual bias against Class D amplifiers diminishes.