Solid State Preamp Reviews

I can't think of a product that was as eagerly anticipated as was Ayre's KX-R preamplifier ($18,500). Following in the footsteps of Ayre's MX-R monoblock amplifier, a Stereophile 2007 Product of the Year, and milled, like the MX-R, from a 75-lb billet of aluminum, the KX-R also shares with its monoblock stablemate the Ayre ethos of zero feedback and fully balanced operation. But what really caused the buzz was the declaration by Ayre founder and chief designer Charles Hansen that the KX-R, with its use of a technology he calls Variable Gain Transconductance (VGT) to control the volume, would set new standards for signal/noise ratio.

When David Hafler sold his Hafler and Acoustat companies to in-car audio manufacturer Rockford-Fosgate a year or so back, things went quiet for a while as the new owners made arrangements to transfer production of both brands to their Arizona facility and took stock of where their new acquisitions stood in the marketplace. Then, at the 1989 CES in Las Vegas, the company made a reasonably sized splash with the first in a new range of Hafler products intended to lift the brand out of the hobbyist-oriented identity it had, perhaps inadvertently, adopted in the last few years.

I'm old enough to remember my family's first table radio that was made out of plastic. It was cream-colored, and it sat on the rearmost edge of our kitchen table: a less-than-timeless design in its own right, destined to be discarded at the end of one era and treasured again at the dawn of another, for more or less the same reason. But in 1958, a cream-colored plastic radio looked fresh, clean, and right, and its cheap wooden predecessor seemed dowdy and sad by comparison. That would all change in later years, of course. Then it would all change again.

Boulder Amplifiers, named after the Colorado town where the company has resided since its founding 23 years ago, makes some of the most elegant-looking solid-state amps around. Chassis are anodized, aircraft-grade aluminum with rounded edges, machined and finished in-house. The two models reviewed here, the 810 line preamplifier and the 860 power amplifier, each have a sleek, compact build—stacked atop each other, the two stand just over a foot high—owing to extremely efficient packing of the circuitry inside. These are the company's "entry-level" electronics, but there's nothing cheap about them—the preamp retails for $6900, the amp for $8500—and for all their economical size, they look like luxury goods as well.

There's always a certain amount of jockeying for position at the very top of the High End. Every few months, a new star burns brightly, getting all the attention. While the constant turnover at the cutting edge helps to define the state of the art, audiophiles should keep their eyes on the longer term. It's a company's track record—examined over a period of years—which defines its position in the market and the credibility of its products.

With the introduction of the NHB-108 stereo amplifier, Swiss-based darTZeel quickly established a reputation for pristine, hand-built quality, fanciful industrial design, and elegant circuitry—all accompanied by a healthy jolt of sticker shock. (See John Marks' coverage in his September 2003 "Fifth Element" column, followed by Wes Phillips' full review in April 2005 .) The 100Wpc (into 8 ohms) NHB-108 costs more than $18,000. A lot of change for not a lot of power, but the reviews were unanimous in praising the amp's exceptional sound quality.

Klyne Audio Arts has an almost Zen-like approach to the design of its products. Like the best Japanese designs, Klyne's preamps are aesthetically pleasing in appearance, do exactly what they're supposed to, and their controls are not only where you would expect them to be, but have an almost sensually smooth action. Internal construction, too, is a work of art—the kind of design which, transferred to a tapestry, would grace the wall of any listening room. You have to see the insides of a Klyne preamp to appreciate how attractive-looking an audio component can be. But physical beauty is only one aspect of Stan Klyne's designs; of all the electronics manufacturers I know of, Klyne Audio Arts also makes products more adjustable than any others, so as to appeal to the needs of what I call compulsive tweaks.