With iTunes playing back CD data, well-balanced rock recordings such as Mary Chapin Carpenter's version of Jagger and Richards' "Party Doll,"…
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I wasn't sure what to expect from the M2. My experience of class-D amplifiers has been somewhat limited, but from that experience I anticipated taut, dry lows, somewhat threadbare highs, and a flattened soundstage. I got none of those things. Instead, when I fed the M2 the 24-bit/88.2kHz master files of Cantus's While You Are Alive (CD, Cantus CTS-1208), the soundstage was wide and deep, the high frequencies silky smooth, the lows warm and rich.
Sidebar 1: Specifications
Description: Solid-state, stereo integrated amplifier with remote control, four digital and two analog inputs, digital processor loop, RS-232 port, 12V trigger input and output, and soft clipping. Digital input sample rates accepted: 32–192kHz at up to 32-bit word length. Clipping power: >250Wpc into 8 ohms (>24dBW). Maximum continuous power: >200Wpc into 8 ohms (>23dBW), >250Wpc into 4 ohms (21dBW), >300W into 2 ohms (18.8dBW). IHF dynamic power: 300Wpc into 8 ohms (24.8dBW), 450Wpc into 4 ohms (23.5dBW), 600W into 2 ohms (21.8dBW). Maximum…
Sidebar 2: Associated Equipment
Digital Sources: Ayre Acoustics C-5xeMP, dCS Puccini disc players; Apple Mac mini (G4 processor, 1GB RAM) running OS10.4.11 for media storage & playback with iTunes 9.0, used with Bel Canto USB Link 24/96.
Power Amplifier: Simaudio Moon Evolution W-7.
Loudspeakers: Aerial Acoustics 20T V2, PSB Synchrony One.
Cables: Digital: Kimber Illuminations Orchid AES/EBU, AudioQuest VSD-4, Stereovox XV2 S/PDIF, Belkin Gold USB 2.0. Interconnect: AudioQuest Wild DBS, Ayre Acoustics Signature (both balanced). Speaker: AudioQuest Kilimanjaro, K2. AC: PS…
Sidebar 3: Measurements
The NAD M2 is not the first power D/A converter to have crossed my test bench: the Sharp SM-SX100, reviewed by Michael Fremer in July 2000 had that honor. But as I wrote at the time in the measurements section that accompanied that review, "On the face of it, an amplifier accepting digital input data and operating entirely within the digital domain is a very attractive idea. But as Sharp's SM-SX100 reveals, it takes heroic engineering to make it work, and there are still some compromises involved, particularly in achieving sufficient dynamic range."
The…
It's difficult to believe that the former top model of Vandersteen Audio's line of loudspeakers, the Model 5, has been in production in one form or another since 1997. Time passes quickly when you're having fun. Like all Vandersteen speakers, the 5 was and remains a good value and performance proposition. For all the 5's high technology and excellent performance both measured and audible, its price now starts at under $20,000/pair (up from about $10,000/pair when the 5 was introduced in 1997), including a built-in, proprietary powered subwoofer in each cabinet, and a sophisticated…
The fully balanced crossover network—with crossover frequencies at 100Hz, 600Hz, and 5kHz—uses the highest-quality, best-sounding components Vandersteen could find. Richard V. said he was surprised by the differences in sound quality different types of connectors made; after trying all of the types commercially available, he decided to make his own. His biwirable terminals, mounted in a barrier strip with machined Teflon insulation, are positioned so that the connectors can be soldered directly to the crossover board, which is located directly behind the terminal panel, inside the cabinet.…
Soundstages were as wide and deep as was appropriate to the program material, but their height was less than fully realized—not surprising, given the Model Seven's height of only 3' 8". Still, the sonic pictures extended well north of 44", just as their width and depth pushed well beyond the physical boundaries of the baffles—but if you're used to line-source arrays—or tall, well-integrated speakers, as I am—the low ceiling of the Sevens' soundstage will be noticeable. That single minor limitation is easily forgotten, however, given the clarity, coherence, and transparency of the three-…
Sidebar 1: Specifications
Description: Four-way loudspeaker with powered subwoofer. Drive-units: ¾" rear-firing aluminum-alloy dome tweeter; 1" dual-chamber, carbon-fiber sandwich, composite-dome tweeter; 4.5" carbon-fiber/balsa composite-cone midrange unit; 7" carbon-fiber/balsa sandwich composite-cone midbass unit; 12" dual-motor, push-pull aluminum-cone subwoofer. Subwoofer amplifier: built-in, 400W, with 11-band room-response compensation. Frequency response: 22Hz–40kHz, ±2dB. Nominal impedance: 4 ohms (+4, –0.5 ohms). Sensitivity: 83.5dB/W/m.
Dimensions: 44" (1117.6mm) H by 14" (…
Sidebar 2: Associated Equipment
Analog Sources: Continuum Audio Labs Caliburn, Cobra, and Castellon turntable, tonearm, and stand; Graham Phantom II tonearm; Oracle Delphi Mk.VI turntable, Oracle/SME tonearm; Lyra Titan i, Ortofon MC A90, Transfiguration Orpheus cartridges.
Digital Sources: Camelot Roundtable DAC, BPT-modified Alesis Masterlink hard-disk recorder, Sooloos music server.
Preamplification: Manley Steelhead, Einstein Turntable's Choice, Sutherland The Hubble, AMR PH-77 phono preamplifiers; darTZeel NHB-18NS preamplifier.
Power Amplifier: Musical Fidelity Titan.
…
Sidebar 3: Measurements
Other than the in-room and nearfield measurements, for which I used an Earthworks QTC-40, the quasi-anechoic measurements of Vandersteen's Model Seven were all performed using DRA Labs' MLSSA system and a calibrated DPA 4006 microphone. The Seven has a low specified voltage sensitivity of 83.5dB/2.83V/m; my estimate of the figure was within experimental error of the specification, at 84dB(B)/2.83V/m. As well as requiring an amplifier capable of swinging enough volts to play at high levels, the Seven also needs high currents, especially with its rear tweeter…