Integrated Amp Reviews

I'm a basically a tube guy, but I've never warmed up to most lower-powered integrated tube amps. Although I quite enjoyed the time I spent with the Cayin A-50T, which I reviewedhttp://www.stereophile.com/integratedamps/308cay">reviewed; in the March 2008 issue of Stereophile, over the years I've typically found I'd rather spend time with mid-priced, solid-state integrateds from Creek, Musical Fidelity, or Simaudio than deal with the loss of definition at the frequency extremes that I've heard from many lower-powered tube models. So it was with a bit of trepidation that I approached the VSi60, a 50Wpc integrated amplifier from Audio Research Corporation.

Leben Hi-Fi Stereo Company is a very small company in Amagasaki City, Japan, that hand-builds an exquisite line of vacuum-tube audio electronics. I find it intriguing that Taku Hyodo, founder and main man of Leben, once worked for the comparatively huge Luxman firm. Years back, Luxman went through various corporate owners and spent some time wandering in the desert, before returning to its high-end audio heritage. Whether, as I suspect, Leben was founded during Luxman's years of ownership by car-stereo maker Alpine, or if Hyodo simply wanted to be the captain of his own destiny, I don't know.

An audio/video receiver in Stereophile? Heresy!

There's a fantastic new two-SACD/CD set of a demonstration-quality live recording of a rather obscure work you really should get to know, not only for its own merits, but also for what I believe is its underappreciated but major influence on music and on popular culture. The piece is by 20th-century composer Arnold Schoenberg, but trust me—it's more than "listenable." It (or, at least, the music on the first disc) is beyond engaging; it is compelling—a revelation, even. The work is Gurrelieder (Songs of Gurre), Gurre being a castle in medieval Denmark that was the setting of a real-life doomed love triangle, the story of which has since loomed large in the moodily brooding artistic consciousness of Danes. The 19th-century Danish poet Jens Peter Jacobsen wrote a collection of poems based on medieval legends, including this one, and a German translation by Robert Franz Arnold provided Schoenberg's dramatic texts.

To celebrate his 30 years with the company, Marantz threw designer Ken Ishiwata a birthday party in the form of an assignment: Design a new, limited-edition integrated amplifier and SACD/CD player bearing his initials. (Only 500 of each will be made worldwide.)

In an industry whose newest products are often as discouragingly unaffordable as they are short of the sonic mark, the Naim Audio Uniti ($3795) stands out. In a single reasonably sized box, the Uniti combines the guts of Naim's Nait 5i integrated amplifier and CD5i CD player with various additional sources: an FM/DAB tuner, and interfaces for an iPod, a USB memory stick, an iRadio, and a UPnP-compatible connected computer or server—all for the price of a very good television set.

A decade ago, many predicted that amplifiers with switching or class-D output stages would come to dominate high-end audio. In a post–Peak Oil world in which the price of energy would always continue to rise, a class-D amplifier's very high efficiency in converting AC from the wall outlet into speaker-driving power would be a killer benefit. Although a conventional push-pull class-B amplifier has a theoretical efficiency of 78.5%, which would seem usefully high, this efficiency is obtained only at the onset of clipping; the need for the output devices to carry a standing bias current reduces that efficiency considerably, typically to around 50%. Class-A amplifiers are even less efficient, with a maximum of 25%; ie, three times as much power is dissipated by the amplifier as waste heat as is used to drive the loudspeaker (see "Sam's Space" in this issue).