NAD M2 Direct Digital integrated amplifier Page 3

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.

With iTunes playing back CD data, well-balanced rock recordings such as Mary Chapin Carpenter's version of Jagger and Richards' "Party Doll," from Party Doll and Other Favorites (CD, Columbia CK 68751), had a delightful palpability in the midrange, and where reverberation had been used in the mix, the source moved back appropriately in the soundstage.

And even when the recording was not good, its poor qualities were handled by the M2 without exaggeration or tonal emphasis, allowing them to be mentally categorized and put to one side. One of my favorite Miles Davis albums, for example, We Want Miles, recorded in 1982 (CD, Columbia 469402 2), was not well served by the engineers, sounding bright, hard, and in-your-face, even on the original LP. Yet with the M2, the brashness seemed to be reproduced in a plane different from that of the music. "Kix" begins with a jaunty figure from Marcus Miller's bass, with first congas, then full drum kit accompanying, before Miles enters with a typically sparse melodic line. Miller uses a funky, hammered-on percussive style for this passage, followed by a mellower, thumbed walking-bass line in the solo trumpet, sax, and guitar sections. The M2 fully distinguished between these different tonal qualities and did a good job of retrieving the ambience around the bass and congas. And the M2's treble didn't exaggerate this recording's splashy-sounding cymbals.

Driving both the Aerial and PSB speakers, the M2 got right both the clarity and the weight of the piano's left-hand register. However, I did wonder if the bass region was a touch too ripe: while Marcus Miller's Fender on the thin-balanced We Want Miles sounded tonally right, Phil Lesh's bass on the Grateful Dead's Live/Dead (CD, Warner Bros. 1830-2) sounded fuller than I'm used to, though not so much as to interfere with the music. In fact, this fullness helped add a degree of majesty, not only to rock recordings and large-scale classical works, but even to smaller ensembles, such as the collection of Mendelssohn's complete String Symphonies, with Lev Markiz conducting the Amsterdam Sinfonietta (BIS 1738, more than four hours of music on one SACD), which I'm slowly working my way through.

In fact, I kept returning to the M2's retrieval of subtle sonic cues in the mix, particularly of ambience. There was more there there, in the immortal phrase coined by Sam Tellig channeling Gertrude Stein, compared with the Simaudio Moon Evolution W-7, itself no slouch in this area. "Blizzard Limbs," from Attention Screen's Live at Merkin Hall (CD, Stereophile STPH018-2), for example, starts with Mark Flynn playing a repeated figure on kick drum, hi-hat cymbal, and a snare rimshot. In mixing this album, I used what I then thought was just enough of the distant omni mikes to give a sense of the hall's acoustic while preserving the immediacy of the instrumental sounds. With the M2 driving the Aerial speakers, and playing back the hi-rez master files, there was more of that hall's character evident than I remembered. Not that it didn't sound musically satisfying, but the soundstage was now both deeper and a little more reverberant than I had originally intended.

On Attention Screen's purist-miked Live at Otto's Shrunken Head (CD, Stereophile STPH020-2), the image of the four musicians was more solidly resolved. And on Robert Silverman's set of the complete Beethoven sonatas, which I recorded in 2000 (CD, OrpheumMasters KSP-830, now sadly out of print), the acoustic of the relatively intimate performing space was sufficiently well resolved that the fact that the room was a little small for the Bösendorfer 9' grand piano could be more readily accommodated to, as it would be heard live.

All of the above comments describe the sound of the M2 as driven from its digital inputs. The analog inputs are certainly of high quality, but feeding the dCS Puccini's balanced analog out to the M2's analog input gave a sound that, with CDs, wasn't quite as well resolved as when I used the Puccini's digital output to drive the M2. (Setting the balanced Input Offset to –9dB on the M2 resulted in a 0.4dB difference in level that could be compensated for by adjusting the Puccini's own volume control.) During the review period, I was auditioning the gold CD reissue of Arturo Delmoni's recital of works for solo violin by Ysaˇe, Kreisler, and Bach (John Marks JMR14; the gold edition is available exclusively from this website. Yes, this recording is an ambiencefest, and that came though via the M2's analog inputs—but the violin was a little more forward in the soundstage than via the NAD's digital input. And a brief reference back to the Simaudio pre/power combination I used for last December's review of the Puccini revealed that for SACD playback—in which, of course, the player's digital output is disabled—the dCS system provided the ultimate sound quality with the Aerial speakers, edging ahead of the sound of the M2 fed by the dCS's analog outputs.

Overall, however, my time with the M2 was among the more enjoyable periods I have spent reviewing an audio component.

Summing up
This review proved a more difficult undertaking than I had expected. My system has been locked into the paradigm of Source Component(s) to Preamplifier to Power Amplifier(s) for the past three decades. When I decided to review the NAD M2, I had not appreciated just how radically it would shift that paradigm. The integration of a D/A processor and power amplifier into a single chassis eliminates the need for an actual preamplifier, instead substituting a digital-domain volume control and switching. Of course, the M2 does have two analog inputs, but as these are digitized ahead of the volume control, it doesn't affect the picture I have painted of the M2 as a paradigm-breaking component.

Once I had changed my system approach, the NAD M2 provided many nights of extended listening, with one album leading to just one more. And one more. While the M2 is relatively large and heavy for a class-D amplifier, runs warmer than you might expect, and is not inexpensive, when fed high-quality PCM data it offers sound quality that competes with that of the best conventional amplifiers. Given my long-term skepticism about the sonic benefits of PWM amplifiers, that was not what I was expecting. NAD's Masters Series M2 is a winner all the way.

NAD Electronics International
633 Granite Court
Pickering, Ontario L1W 3K1
(800) 263-4641

argyle_mikey's picture

I've craved this amplifier ever since I first read JA's review. It was Class A recommended for a few years, but then just disappeared (there's usually a reason given, but on this occasion I couldn't find one). Maybe they just stopped manufacturing it. Anyway, there's one for £1750 on eBay over here at the moment and I'm sorely tempted...

It would also be interesting to know if the QA issues mentioned in the review were a one-off or whether M2's were plagued by these issues.