LATEST ADDITIONS

For those of us who have succumbed to the enticements of surround-sound for music, Audio Research's SDP1 is both vindication and cause for rejoicing: vindication because surround-sound's acceptance by such an ultraconservative, uncompromising company as ARC will give it a respectability in the high-end community that it never enjoyed before, and cause for rejoicing because someone has finally done music surround right.

About three weeks ago, while perusing the gear in a local audio retail establishment, I overheard a salesman, who could well have been selling used cars, giving a classic spiel to an obviously confused customer. "You see, sir, all preamplifiers basically sound alike, especially with line-level inputs. The only differences are in the number of features." He went on to tell his prey that spending big bucks for high-end products such as Krell or Mark Levinson (neither of which he sold) would be a big mistake. I choked back my automatic response of a certain bovine term, but thought it better to continue my fly-on-the-wall masquerade.

As mentioned by two readers in this month's "Letters," amplifiers are used to drive loudspeakers but are almost exclusively measured into resistive loads. The reasons for this are twofold: 1) real loudspeakers both produce neighbor-annoying sound levels and tend to break when driven with typical amplifier test signals; and 2) the question as to which "standard" loudspeaker should be used is impossible to answer---at least the conventional resistive loads are consistent and repeatable.

As Laura Atkinson shuffled into my listening room one evening, she spied the Stage loudspeakers tucked away in the corner. "Hey, Dick, those look like Apogees, but they're kind of small." Rising to the occasion, I responded with: "Honey, I shrunk the Apogees." At roughly 3' tall by 2' wide, the Stage is far from intimidating; it even feels more compact and is certainly much cuter looking than the old Quad ESL. Yet Junior's resemblance to the rest of the Apogee family is unmistakable. The canted baffle, the vertical tweeter/midrange along the inside edge of the baffle, and the pleated aluminum-foil woofer clearly bear the imprint of the larger Caliper and Duetta models. It's almost as though Apogee started shrinking the Duetta until the price tag shrank below two kilobucks.

The $395 NAIT, rated at 20Wpc, is a good-sounding little amp. It's very open and spacious-sounding, but, like the $250 Rotel RA-820BX, sometimes sounds a little hard in the upper registers.

In the fall of 1982, I had just become the Editor of the English magazine Hi-Fi News & Record Review. Hi-fi was in a state of flux. The Compact Disc had just made its debut in Japan, but the British and American launches were six months and a year away, respectively. The Linn orthodoxy prevailed about the role of the source in system performance, but there was no agreement about what was and was not important when it came to enhancing the musical experience. "Objectivists" insisted that amplifiers and even loudspeakers had pretty much reached a design plateau where no further improvement was necessary or even desirable, while "subjectivists" were fragmented. All I was aware of was that my system, based on Celestion SL6 loudspeakers, needed more of an undefinable something.

This is something we don't see too often: an entirely new approach to power amplifier design. As Quad points out in its literature for the 405, class-A operation of transistors provides the lowest distortion, but drastically limits the amount of power an output transistor can deliver without overheating. (Most transistor amps use class-AB output operation, in which each of a pair of power transistors handles part of each signal cycle and shuts down during the other part. Imperfect synchronism between the two halves causes the familiar "crossover distortion," which accounts for most solid-state sound. In class-A operation, each output transistor draws current though the entirety of each signal cycle, eliminating the crossover transition but doubling the amount of time current is drawn, and thus tending to cause the transistor to heat up more.)