In our last issue we featured a special report on the current crop of Class D amplifiers. Most of us are aware that this technology is already available in a variety of applications—from active loudspeakers and subwoofers to receivers and other multichannel components. Now, Chapter’s Class D Précis enters the premium division of integrated amplifiers.
The Précis (a précis is a summary of the main points of a theory or argument) outputs 130Wpc, doubling that into 4 ohms, and features proprietary Class D power modules. The linestage elements come from the company’s Preface Plus preamp, while the output stage is borrowed from its Couplet amplifier. With its stylish bead-blasted aluminum-alloy casework, the Précis also makes a strong impression as a design statement. A “standby” touch-sensor illuminates from red to blue when the amp powers up, and a blue-lit multifunction front knob controls volume as well as input, display, and preamp functions. With its circular wire-mesh vents and top-mounted glass portal, which allows a view of its tidy internal layout, the Précis conveys a Jules Verne meets Steve Jobs impression. (Speaking of Mr. Jobs, the mini input jack on the front panel is designed for iPod use.)
The single knob elegance of the front panel belies the complexity of the Chapter’s smart software control. Simply punch the knob’s center button to cycle through functions, and give it a forward or backward twist for the preferred setting. Release it and it returns the display to the previous volume setting. The volume control is speed sensitive to the user’s input and employs ultraprecision Melf-style surface-mount resistors for dead-on accuracy at any level. Chapter’s software “vectors” the controller speed between 0.1dB and 1dB steps depending on knob speed or how long the remote-control button has been depressed.
Prior to any intensive listening, I noticed how quiet the Précis was. At least part of the credit should go to Chapter’s efforts to shield components against RF—an issue that has grown in significance in the age of home wireless communications. Chapter also addresses chassis resonance control by using a novel base-plate system in which three sheets of aluminum are bonded together with an elastic polymer agent. Chapter calls this Acousteel Vibration Control.
Sonically, it didn’t take a substantial amount of listening to realize that the Précis competes against a small fraternity of highquality integrated amps, irrespective of class or type. And it does so not by accenting personality disorders but by hewing to honest reproduction, top to bottom. First and foremost, it gets the meat of the tonal spectrum spot on. The midrange is as rich and satisfying as a Kobe steak; the lower midrange and midbass resolution are striking in their tonal density, with just a hint of warmth yet an overriding sense of evenness throughout. Channel separation—an area that normally isn’t a strength of integrated amps—is excellent. At its frequency extremes, the Précis doesn’t quite have the brute force to drag the lower depths or the subtlety to elicit a whisper of harmonic bloom at the treble’s summit, but I never felt short-changed, either.
What the Précis does do is grip low-level information with the kind of punch and energy that emerge from real instruments played in an acoustic space. During Sinatra’s “Angel Eyes” from Only The Lonely [Capitol], it unearthed the deep bass line and a gang of other musical treasures to a degree that I didn’t think possible. Not the least of which was Sinatra’s vibrato—an element of his delivery that he used sparingly. Even the delicate harp accompaniment was followed so precisely that I found myself leaning slightly forward in order to hear deeper into the mix. And even if it didn’t play back the bass of Claire Martin’s “Black Coffee” from Linn’s Too Damn Hot CD as well as the Conrad Johnson CA200 or the MBL 7008, the depth from the snare drum and the natural timbre and growl of a sliding bass string was more than enough to send a couple of shivers down my spine.
Transient response is a strong suit with the Précis. During Arturo Delmoni’s “Obsession” from Water Lily’s Bach, Kreisler, Ysaÿe, the violin was so resonant that it almost tasted of wood, and the highs were wonderfully extended. During aggressively bowed passages, notes were crisp with attack and filled with the inner details of fingerboard maneuvers. This is a characteristic that serves rock fans and classical aficionados equally well. For example, Slayer wouldn’t be the first metal band to come to mind in regard to sound quality, but its new CD Christ Illusion [American] makes clear just how much information and speed reside in the mix, if the electronics are sensitive and dynamic enough to reproduce them. Listening to the intro to “Jihad,” with its simple high-hat flare partnered with Dave Lombardo’s punishing double-kick drum and the churn of multiple guitar rhythms, was at times no less hair-raising than the orchestral climax of Shostakovich’s Eighth Symphony.
The Précis over-emphasizes the upper registers of wind instruments, certain voices, and, during the Saint-Saëns Cello Concerto No.1 [Channel Classics], Pieter Wispelwey’s cello. The amp seems to grow cooler as it reaches up higher in pitch; hall sound also firms up, as if damping has been removed. Strings sound a bit more tightly wound, a touch wiry on top, and slightly forward. And though this makes for a very clean, fast sound, some delicacy and resonance are traded off.
One other area where I felt the Précis might be improved is the mid-treble. The Chapter doesn’t have the same command over soundspace and dynamics in this region as it does throughout the rest of the frequency spectrum. On Bartók’s Concerto for Orchestra [Telarc], for example, the microdynamics and harmonics of complex orchestral passages in the treble were communicated less specifically, as if the flow of sound were being channeled from a wide pipe into a much narrower one. Again, with Reference Recordings’ Rutter Requiem, the resolution of soundstage layers and of individual voices in the chorus was a little less precise.
In the Class D survey mentioned above, Jonathan Valin characterized this anomaly as “top-end compression,” and I think this description is as accurate as any I’ve heard about what appears to be a common issue with switching amplifiers. It’s a sensation less like the grainy artifacts of early transistor designs and more like a scrim overlaying the air of the performance—a tether holding down the ceiling of both instruments and venue. It was the only region where I felt the otherwise-effortless Précis was laboring.
Note that the extent to which this oh-sosubtle trait revealed itself was dependent on cabling. In this instance, it was the TARA Labs “Zero” interconnects that played super-sleuth, uncovering the Précis’ sonic fingerprint in the treble. With most other cables it slipped past virtually unnoticed. On a more philosophical note, it was a reminder that when you hear the full potential of a system the results may be mixed. In this case, the Zero interconnects not only improved the performance of Précis in every area, but also pointed out where the Précis didn’t quite fully rise to the occasion.
The Chapter Electronics Précis is the genuine article. Only a few years ago, this degree of power and finesse in a package no larger than a preamp would have been unimaginable, but today’s premium integrated amps are setting standards that even some separates struggle to match. This includes the Précis—a component that joins the exclusive company of some of the finest integrated amplifiers I’ve heard. TAS