After I read Brian Damkroger's rave review of the Audio Research Corporation's Reference 5 SE line stage in the November 2012 Stereophile, I was excited about getting the review sample into my system so that I could do a Follow-Up (February 2013). However, the sample had already been returned to the factory, so I called ARC to see if it could be rerouted eastward to me. Chief Listener Warren Gehl answered the phone.
"Sure, you can listen to the Ref 5 SE, but I'd assumed you were calling about the Reference 75 amplifier."
"Reference 75? What's that?"
"It's our newest amplifiera half-power version of the Reference 150."
For those who frequent the audio discussion groups on the Internet, the method by which Stereophile selects products for review seems to be a continuing source of fascination and conjecture. Supporters of fledgling manufacturers—whose products these Webcrawlers just happen to own—rail against the rule that products to be reviewed in the magazine must have at least five US dealers. Some suggest that Stereophile's selection of review products is all about catering to advertisers and friends in the industry, a process that seems intended to exclude their favorite products from consideration.
At the 1992 Winter Consumer Electronics Show in Las Vegas, Audio Research showed a line of reference products that represented the pinnacle of founder William Z. Johnson's life work as an amplifier designer. Although the all-tubed, fully balanced preamplifier and tubed monoblock power amplifiers were shown as works-in-progress, it was clear that these were products aimed at advancing the state of the amplifier art with no consideration for cost.
The only thing that excites me as much as finding an excitable new affordable component (which I define as below $1000, and the lower the better) is a new "trickle-down" design from a cutting-edge designer. Thankfully, such new "real-world" products are becoming more commonplace in the High End. The process begins when a talented high-end designer releases an expensive, cutting-edge product that is hailed by the audiophile press as a breakthrough, a new "reference."
The VTM200 is the first Audio Research power amplifier I've reviewed. It took me 13 years, and ultimately I'm glad I'd put that much mileage on my reviewing odometer before tackling what turned out to be a most difficult assignment.
Ah, Brazil...land of coffee, the samba, Pelé, Rio-by-the-sea-o, and tube amplifiers. All right, so perhaps the amplifier connection isn't quite as well-established. But one Brazilian amplifier designer, Eduardo de Lima, has published articles in Glass Audio magazine that are viewed by many as groundbreaking, and his evolving products have been seen at various specialist tube equipment shows. De Lima—president, founder, product designer, and principal owner of Audiopax Sistemas Eletroacusticos—is an electrical engineer who started out designing equipment for a telecommunications company, but since 1995 he's devoted his talents to designing a wide range of audio products, including speakers as well as preamps and power amps.
Victor Tiscareno and Byron Collett of AudioPrism are known in audiophile circles for their complete line of power-conditioning products. (See Barry Willis' omnibus review in the December 1998 Stereophile.) Their intimate knowledge of the ever-capricious electrical supply has resulted in a series of front-end components bearing the company's logo. The flagship Mana Reference monoblocks, under consideration here, represent AudioPrism's collected wisdom and engineering savvy taken to its logical extreme.
In this hobby, nothing's for nothing. To get that gorgeous midrange, with its harmonic depth and inner detail, tube-amp enthusiasts are willing to give up some things in the bass. Tube folks put up with heat and occasional maintenance—routine or otherwise. To get the ideal middle, fans of single-ended triodes are even willing to shave off considerable dynamic range and settle for ultra-efficient speakers that often have limited response at the frequency extremes. Those who say nothing is lost by preferring tubes are in denial.
The VK-150SE stands tall at the top of Balanced Audio Technology's range. It and its smaller brother, the identical-looking VK-75SE stereo amplifier (or, sans the Special Edition mods, the plain VK-75, footnote 1), are related to BAT's first amplifier design, the VK-60. The company's partners, Victor Khomenko and Steve Bednarski, eventually realized that they'd made enough upgrades to the VK-60 to warrant a new model designation, and in 2000 they discontinued the VK-60. Bednarski explained that while the VK-60 accepted the upgrades with good results, the BATboys felt that, in order to fully realize the full potential of the 6H30 SuperTube, a new platform would be required. Enter the VK-75SE and VK-150SE.
It's been 10 years since Balanced Audio Technology (BAT) introduced their first products: the VK-5 line-stage preamplifier and the VK-60 power amplifier. (I reviewed both in the December 1995 Stereophile, Vol.18 No.12.) The success of these and other BAT products has allowed designer Victor Khomenko (the "VK" of the model designations) and partner Steve Bednarski to quit their day jobs at Hewlett-Packard; they were joined by Geoff Poor as a partner to handle the sales end of the enterprise. BAT's current lineup includes several preamps, phono stages, a CD player, and tube as well as solid-state amplifiers. The top of BAT's preamp range is the VK-51SE, which costs $9000; their top tube power amp is the VK-150SE monoblock ($17,000/pair); if you want their best phono stage, the VK-P10 will set you back $8000.
How important is the use of balanced circuit typology in the design of preamplifiers and power amplifiers? Ask the top audio designers (I didn't, but just play along, okay?) and you'll get a wide variety of opinions. Some reject the balanced approach outright, arguing that it represents a needless duplication of circuit components, and that better results can be achieved if the same attention and resources are devoted to perfecting a single-ended circuit. In his provocatively titled article "Balance: Benefit or Bluff?" (Stereophile, November 1994, p.77), Martin Colloms questioned the advantages of balanced designs, suggesting that while the results may be better in certain respects (eg, noise level), the reproduced sound may suffer in other, perhaps more important ways (eg, rhythm and dynamics).
I hate audio shows. All those manufacturers and retailers desperately demonstrating their products, knowing how impossible it is to do them justice in a hotel room. They might be saying, "It has gold-plated circuit boards and unobtainium binding posts," but all I hear is Please love it, please love it, oh puhleeze . . .
I had never been alone with a Russian-manufactured 6C33C tube. At least not at night, in the dark. The first night Balanced Audio Technology's VK-56SE tubed amplifier was in my system, I sat on the floor studying the unusual shape and dark orange glow of its four 6C33C-B output tubes. I noticed their brightly lit, cathedral-like innards. My Russian neighbor told me they were used as regulator tubes in MiG jets during the Cold War. I could believe ittheir exposed cathodes were the exact color of the Soviet flag. From more than a foot away, I could feel the heat from their high-amperage filaments.
Although I retain a firm hold on the established audio world, and recognize and value all that it has achieved, I feel inexorably driven to make some space in my life for single-ended amplifiers—more especially, those that eschew negative feedback (footnote 1). A classic if costly example of the art is the Cary CAD-805C, which, to my ears, has earned the right to teach audiophiles what negative feedback really sounds like, and what damage it can do to the musical message when poorly handled. This shouldn't be taken as an out-of-hand dismissal of those many great pieces of electronics and amplification that use negative feedback—it is simply an acknowledgment, or even an assertion that negative feedback generates a sound of its own.
Although one of the most innovative firms in the audio electronics field, the David Berning Company seems determined to keep as low a profile as possible. The company advertises little, does not actively seek out new dealers, and seems content to let potential customers seek it out, as though to say "Okay, here's my product, take it or leave it." Thus, even though both Stereophile and The Absolute Sound, in a rare outbreak of agreement, a couple of years ago declared Berning's TF-10 to be one of the best preamplifiers available, most serious audiophiles are still unaware of the Berning Company's existence. Perhaps the EA-2100 will change that.