Cary’s A 306 Class D amplifier, part of the new Designer Series that includes the superb CD 306 CD/SACD player I reviewed in Issue 164, is big and heavy enough to be mistaken for a conventional linear amplifier. With an 18-inch-wide chassis and a weight of 50 pounds, the A 306 isn’t the prototypical switching amplifier that you can hold in the palm of your hand.
Much of the A 306’s heft comes from the unit’s dual power transformers, which are comparable in size and weight to those found in a linear amplifier. (A third transformer supplies the control circuitry.) Cary believes that good powersupply design is of the utmost importance in a switching amplifier, and went to great lengths in the A 306 to create a massive supply. Indeed, the A 306 is rated at a whopping 600Wpc into 8 ohms and 1100W into 4 ohms. A linear amplifier of this power would weigh several times the A 306’s 50 pounds. Conversely, the other Class D amplifiers reviewed in this issue are a fraction of the Cary’s size and weight (although none puts out as much power).
The A 306 is built around the ICEpower module (see the accompanying technical background article on Class D amplification). Cary modifies the module, as well as adds its own circuit designs around the ICEpower unit. The fully balanced A 306 was voiced with full-range electrostatic loudspeakers, which present both a low impedance and a reactive load (which can spell trouble for some switching amplifiers).
The unit is housed in a gorgeous, all-aluminum chassis with no visible screws. The front panel contains an etched-crystal panel that illuminates the Cary Audio Design logo in a soft blue light. Binding posts are the outstanding Cardas units, which are vastly better than five-way posts. A rear-panel switch selects between unbalanced and balanced inputs.
The Cary was the first Class D power amplifier I auditioned outside those in AV receivers and powered subwoofers. I was immediately struck by its bottom-end wallop, dynamic effortlessness, and seeming unlimited power reserves. Orchestral crescendos were reproduced with no sense of strain, congestion, or change in soundstaging—and I’m used to the extraordinary dynamics and bottom-end of the BAT VK-600SE monoblocks.
Spatially, the A 306 had only fair soundstage depth, and width was somewhat constricted. The overall perspective was a little forward and aggressive, with recorded detail (percussion, for example) tending to be presented at the front of the soundstage. I also thought the A 306 tended to blur individual instrument’s spatial outlines as well as their tonal colors. I got less of an impression of distinct performers within the soundstage through the A 306 than I did, for example, with the NuForce Reference amplifiers. There was a kind of opacity and thickness to the presentation that just sounded wrong.
In the mids and treble the A 306 sounded different from all the linear amplifiers I’ve heard. There was something mechanical and artificial about the sound. Massed strings, for example, had a kind of “chalky” coloration that made the sound somewhat synthetic rather than natural and organic. I heard this artificial quality on other instruments as well. The tune “Valentino” from Victor Feldman’s Secret of the Andes (originally a Nautilus direct-to-disc, now re-released as the XRCD title Audiophile) features Hubert Laws on flute; through the A 306 the flute lacked the sense of air moving through a tube. This character wasn’t present in instruments with less upper-midrange-to-lowertreble energy (bass clarinets, for example), and only became apparent on violins, saxophones, cymbals, and other instruments rich in high-frequency overtones. The extreme top end sounded closed-down, reducing the impression of air and extension.
I have the greatest respect and admiration for Cary’s SET amplifiers, their linear solid-state designs (the Cinema Series is outstanding), and the company’s terrific CD 306 CD/SACD player. Unfortunately, that design expertise didn’t translate into the Class D world, at least as realized in the A 306.
Wayne Garcia comments on the Cary 306
I’m not sure what the folks at Cary had in mind when they released this model, but it surely won’t do the company’s reputation any good. Aside from muscle and a big ol’ whomping bottom end, which I’ll admit was exciting on a rock CD like the Yeah Yeah Yeahs’ Show Your Bones [Interscope], the 306 has nothing to recommend it. Its top end sounds wrong. It not only lacks air; it is strangely rolled off yet jitterybright. Its midrange has a weird shimmering nature, like heat rising off hot pavement; it lacks detail; and unlike most Class D models, which are tiny or relatively so, this thing is the size and weight of a Class AB unit, which robs it of Class D’s tinyis- cool factor.