November 2004

Accustic Arts Amp II-AC High Performance Stereo Amplifier

by Jeff Fritz

Review Summary Sound "The Amp II-ACHP came across as sounding honest. Its presentation was balanced -- no aspect of its sound stood out. In fact, you might initially have a hard time identifying a sonic fingerprint from which to identify it." "A sharply focused soundstage, a smooth-sounding midrange and upper frequencies, and a general lack of veiling across the musical spectrum" define the Amp II-ACHP's performance. Features "Massive" solid-state amp that delivers "240Wpc into 8 ohms, 400Wpc into 4, and a whopping 600Wpc into 2 ohms." "The output stage consists of 24 MOSFET transistors, 12 per channel, while filter capacitance is specified as 160,000 microfarads." "The Amp II-ACHP is available in three different forms: the standard Amp II-AC with RCA inputs ($9000 USD), the balanced version of the standard amp ($9600), and the XLR High Performance version ($10,500)." Use "It should be noted that ordering the balanced Amp II-AC -- in either standard or High Performance guise -- will get you XLR inputs only, although XLR-to-RCA adapters can used." The rear-mounted fuse button "must be held down for a full three seconds to power up the amp." Value "There are better amplifiers than the Accustic Arts Amp II-ACHP, but you’ll have to spend considerably more money to get a small measure of 'better.'"

Although you may not have heard of the Accustic Arts brand name, the company behind it looks to be poised to become a force in specialty audio. In fact, in some parts of the world, Accustic Arts already is a force, evidenced in part by the exposure at the European High End show each year. Here in North America, however, the brand has until just recently kept a low profile.

Accustic Arts audio components are manufactured by Schunk Audio Engineering GmbH & Co., in Lauffen, Germany. What initially impressed me about the company, which led to my interest in this review, is the manufacturing prowess the parent company seems to possess over a full product line that includes: three amplifiers; an integrated amp; a preamplifier; a CD player, transport and DAC; as well as a line of speakers, cables and furniture. Accompanying the diversity of manufacturing is, apparently, equally adept electrical-engineering talent. The company's facility is featured prominently on the Accustic Arts website, and it appears to be the model of clean, efficient manufacturing.

Does all of this equate to good-sounding gear? It’s not enough to make all of the components I listed above; each one must be designed for audiophile performance from the start. If my experience with the Amp II-AC High Performance amp is any indication, Accustic Arts products appear to have the right stuff.

"Big Beauty"

Accustic Arts calls the Amp II-AC High Performance amplifier (Amp II-ACHP) the "Big Beauty." Whether the term sums up exactly what the company meant or something was lost in the marketing department’s translation, I can’t say. Regardless, the amp itself is big and, in a German sort of way, attractive. (I can’t bring myself to use the term beautiful when describing an amplifier, no matter how hard I try.) The Amp II-ACHP is 14"H x 19"W x 17"D, making it appear massive while viewing it straight-on due to the imposing height. The appearance of the outer casework demands attention. The silver version I received is hard to miss, although I imagine the black edition appears a little more conventional for those inclined to go that route.

The finish options are only the beginning, however. Although the general external appearance remains unchanged, the Amp II-ACHP is available in three different forms: the standard Amp II-AC with RCA inputs ($9000 USD), the balanced version of the standard amp ($9600), and the XLR High Performance version ($10,500) under test here. The 121-pound playing weight of the Amp II-ACHP represents about a ten-pound advantage over the non-High Performance versions of the product due to an increase in transformer size: two magnetically shielded, potted 1100VA toroidals in a dual-mono configuration versus two 700VA units in the standard amps. The increased-capacity power supply helps the Amp II-ACHP deliver a rated 240Wpc into 8 ohms, 400Wpc into 4, and a whopping 600Wpc into 2 ohms. The output stage consists of 24 MOSFET transistors, 12 per channel, while filter capacitance is specified as 160,000 microfarads. Comprehensive protection circuitry guards against clipping, high-frequency oscillation, and excessive DC offset. It should be noted that ordering the balanced Amp II-AC -- in either standard or High Performance guise -- will get you XLR inputs only, although XLR-to-RCA adapters can be used.

Fit and finish are what you would expect of an amplifier that costs over ten Gs: excellent. The faceplate is nicely machined aluminum with beveled edges and a chrome insert displaying the Accustic Arts logo as well as the push-button standby switch. The rear panel is outfitted with two sets of high-quality WBT binding posts for biwiring, a main power switch, the aforementioned XLR inputs, and a fuse button that must be reset anytime the unit is unplugged (The latter must be held down for a full three seconds to power up the amp, a fact that I initially overlooked, and one which caused me much frustration). The only criticism I have of the build is the somewhat thin, and therefore a bit flimsy, top plate. I would think a little more structural integrity could be gained from a slightly thicker panel covering the innards.

Busy rotation

My system has taken on many permutations during the course of this review. The Accustic Arts Amp II-ACHP was used with three different preamps: the Audio Research MP1, the Orpheus Labs Two, and a Blue Circle BC3000 Mk II, all of which provide balanced outputs, thereby avoiding any potential sonic degradation from adapters. Sources were the Esoteric DV-50, also used balanced, and the Lexicon RT-10. Both are universal audio/video players and were used with a variety of CD, SACD, and DVD-Audio material. I used Nordost Red Dawn interconnects and Red Dawn II speaker cables. Power conditioning was provided by a pair of Shunyata Research Hydra Model-2s and a single Model-8. Wilson Audio X-2 Alexandrias anchored the speaker section.

The Amp II-ACHP operated without a hiccup throughout the review period and was mechanically silent during operation. I could hear no transformer buzz coming from inside the amp with my ear placed just a few inches away from the vented top plate. Whether coincidence or not, I’ve found amplifiers that have potted transformers, which the Accustic Arts amplifier does, to be much less susceptible to hum and mechanical noise. I don’t know about you, but buzzing electronics drive me crazy. The Amp II-ACHP was silent.

Sound

First impressions with a variety of music were positive. The sound of the Accustic Arts amp immediately characterized itself with a sharply focused soundstage, a smooth-sounding midrange and upper frequencies, and a general lack of veiling across the musical spectrum. The Amp II-ACHP came across as sounding honest. Its presentation was balanced -- no aspect of its sound stood out. In fact, you might initially have a hard time identifying a sonic fingerprint from which to identify it. This is usually a good sign, and oftentimes is one indicator of long-term satisfaction. I could find no instance where the Amp II-ACHP spot-lit certain areas of the musical spectrum, nor did it add any haze or impurities to the sound of my most demanding recordings.

Eva Cassidy’s Live at Blues Alley [Blix Street 10046] has become a favorite recording of late, with its forthright and natural-sounding presentation. The intro to "Tall Trees in Georgia," where Cassidy is introducing the song to her audience, presents a good opportunity to hear her spoken words without any instrumental accompaniment (except for an occasional strum of the guitar). The ambient environment of Blues Alley is tactile, as is Cassidy's voice. The Amp II-ACHP reproduced Cassidy right in front with no image wandering or veiling of her voice. It also let the crowd and background noise through clearly without burying any details. The Accustic Arts amp handled this, the simplest yet hardest of tests, the human voice, with apparent ease. The rest of the album also provides a good test, as a number of acoustic instruments accompany Cassidy. The Amp II-ACHP was able to keep the many elements of the performance separate, with no congestion or blurring.

Lest you think 240Wpc is lightweight in a world where super-powerful solid-state amplifiers are more common every day, don’t give it a second thought. Just to see if I could make the Amp II-ACHP lose its composure I tried a frantic blast from Guns N’ Roses Live: Era ’87-‘93 [Geffen 490514]. The available power from the Amp II-ACHP proved to be more than sufficient for exuberant listening levels -- "Rocket Queen" for all the neighbors to hear. My ears definitely gave up before the Accustic Arts amp did. Would more power sound better, or different? I wouldn’t count on it. I’ve heard intoxicating dynamic ease from amplifiers like the big Krell FPB-700cx, but I also heard that with the Accustic Arts Amp II-ACHP. And there’s no guarantee that a more powerful amp would get the small-scale stuff right, as the Amp II-ACHP did. If you’re considering one of the monster amps partly because of a high power rating, don’t count out this amp. Unless you have hugely inefficient speakers, I can’t imagine the Amp II-ACHP not having enough juice. It also kept perfect composure when playing loud. Well, as composed as possible while playing G’N’R.

I’m grown quite fond of Laurie Anderson’s Strange Angels CD [Warner Brothers WB25900-2], particularly "The Dream Before." This track manages a delicate balance between instrument and voice. The Amp II-ACHP was able to reproduce the quiet, delicate moments without losing any detail to the noise floor or shrinking the soundstage to an unnaturally small size. Just as we want our large floorstanding speakers to sound small when the occasion arises, we also want our powerhouse amps to shrink to the task of the more subtle recordings. The Amp II-ACHP strikes a fine balance between power and finesse, not sacrificing one for the other. Bass weight was solid, which was evident on the first 45 seconds of "Monkey’s Paw." The sound was well paced and composed, just as you’d want.

Enter Gryphon and Halcro

I’ve been fortunate to hear a fair sampling of some of the best solid-state and hybrid amplifiers available, all within the context of the same timeframe, same system and same room. The Accustic Arts Amp II-ACHP had some tough acts to follow as it entered my listening room, and it held up pretty well considering the price of some of the competing behemoths. To be honest, it’s only in comparison to these world-beaters that the Amp II-ACHP's limitations come to light.

Compared with the Gryphon Antileon Signature stereo amplifier ($24,000), the Amp II-ACHP scored points with a lower noise floor and a more sharply focused soundstage. Where it fell down against the big Dane was in bass weight and authority, absolute cohesiveness of the musical spectrum, and in soundstage width and depth. Even though the Gryphon is rated at a mere 150Wpc, that rating is deceiving (the Gryphon operates in scaldingly hot pure class A ). The Gryphon’s powerful nature translates into more grunt with double bass and more impact with kickdrum. The soundstage opens up wide and naturally with an ease that the Accustic Arts amplifier just can’t manage. The Gryphon amp produces more ambient bloom as well, while maintaining terrific soundstage focus in its own right.

The Amp II-ACHP did not sound more or less powerful than the Halcro dm68 monoblocks ($38,000). The German amp was wholly competitive with the 225Wpc Aussies in almost every respect until I reached the upper frequencies, where a lack of any noise, and frequency extension for miles, put the Halcros in a league unto themselves. The dm68s also sounded slightly quicker than the Amp II-ACHP, although only by the slightest of margins. The Accustic Arts amp, though, did hold together the soundstage as well as any amp I’ve heard. I know I keep coming back to the term focus, but that is one key to the Amp II-ACHP's sound. If your speakers don’t have quite the image specificity that you’d like, try the Amp II-ACHP and see if doesn’t improve.

At the end of the day, the Accustic Arts Amp II-ACHP competed in a price category that more than doubles its own. While it was clear to me that you can get better sound in some areas by spending more money, you’ll find some performance characteristics that are simply hard to beat with the Amp II-ACHP. You may still choose amplification like that from Gryphon or Halcro after hearing this amp, but at least you’ll know what you’re laying out all that additional dough for.

The end

There are better amplifiers than the Accustic Arts Amp II-ACHP, but you’ll have to spend considerably more money to get a small measure of "better." The frequency extremes can be improved upon by shelling out the big bucks, but each listener will have to decide whether those performance improvements are important. The fact is that it’s only in comparison to some substantially more expensive amplifiers that I was able to fault the Accustic Arts Amp II-ACHP at all. There were no glaring errors, and plenty of things to praise.

The bottom line is that Accustic Arts and the Amp II-AC High Performance are real players in an industry populated with fine-sounding amplifiers. The Amp II-ACHP casts a sharply defined soundstage while producing a balanced, clear view into the music. It’s also a powerhouse of an amp. This "Big Beauty" may prove a popular alternative to the usual suspects if its list of strengths is attractive to your audiophile sensibilities. Keep an eye out for Accustic Arts products, and the Amp II-ACHP, at a dealer near you.

...Jeff Fritz
jeff@soundstage.com

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