Stereophile M3 Review
February 19, 2007
January 2007 by Michael Fremer
Masters Series M3 INTEGRATED AMPLIFIER
Older audiophiles remember the splash NAD made in the late 1970s with the introduction of their 3020 integrated amplifier ($175). Ridiculously cheap, it looked graceful and sounded warm, inviting, and holographic. Removable jumpers between the 3020's sections permitted enthusiasts to determine whether the magic resided in its preamp, its power amp, or in some synergy of both.
In the opinion of most listeners, it was both. But while the 3020's relatively low-powered amplifier (conservatively rated at 20Wpc into 8 ohms) limited it to driving small, efficient loudspeakers, its remarkably fine-sounding preamp section, complete with a decent moving magnet phono stage, inspired many buyers to eventually add a more powerful outboard amp and go the biamp route—or, given the 3020's low price, to ignore the NAD's power amp altogether. Consumer demand led NAD to later release the preamp section on its own, as the bargain-basement-priced 1020.
NAD was able to achieve such high performance at such low prices by avoiding the high capitalization costs involved in building a factory to produce its products. Instead, it had them manufactured to its specifications in existing factories in Taiwan. While this arrangement is commonplace today, back then it was unusual, even radical.
The M3 dual-mono integrated amplifier, one of NAD's new "Masters Series" products, appears to be the company's latest attempt to produce another two-channel classic, this time one combining excellent build quality with cutting-edge electronic engineering, 21st-century remote-control ergonomics, and high-end sound. Like the 3020, the M3 is the product of NAD's director of advanced development, Bjørn Erik Edvardsen, and Asian manufacturing expertise, this time in the People's Republic of China. The more things change, the more they stay the same.
Unlike the 20Wpc 3020, which was inexpensive and looked it, the 180Wpc M3 costs much more than many entry-level two-channel integrateds. Even so, its build quality seems that of a product costing many times its $2799 price. The chassis is made of 2mm-thick milled steel plates, the front panel of extruded aluminum and diecast zinc. Feet of aluminum and silicone rubber help isolate the circuit boards from vibrations. Line-level connections are made via gold-plated, chassis-mounted RCA jacks. The finish comprises a brownish powder coating and an advanced automotive paint; these, along with the chassis' smoothly rounded contours and heatsinks, give the M3 a coherent, understated beauty that's rarely achieved in audio at any price.
Digital nerve system, analog musculature
With six pairs of single-ended and one pair of balanced inputs, the M3 offers enough versatility for almost anyone's audio system. Two sets of speaker output terminals are provided on the roomy, cleanly laid out rear panel, each using those annoying Euro-spec plastic-protected connectors—fine for banana plugs, pins, or bare wire, not so fine for audiophile-grade speaker cables, most of which are terminated with spade lugs.
The simplicity of the M3's front panel hides a versatile, feature-packed preamplifier section with seven custom-namable inputs (including a balanced XLR), electronically activated bass, treble, and "Spectral Tilt" controls, dual-mono, stereo, mono left and mono right modes, a balance control, independent source selection for a second zone, and two preamp outs, one of which features a selectable biamp mode with built-in 40, 60, 80, and 100Hz low-pass analog filtering for use with a satellite/subwoofer system.
Dominated by a large, fluorescent display, the front panel includes a row of small pushbuttons labeled Listen (input selection), Record/Z2, Mode, Balance, Tone, Bi-Amp, and Speakers. A single large knob controls not only the volume, in continuous 0.5dB steps over a range of –77.5dB to +10.0dB, but setup as well. While using the Listen button requires you to scroll through the entire list of inputs to reach the one you want, large pushbuttons on the remote provide direct access.
According to NAD, all of this versatility and control comes at no sonic price. Level adjustments (volume, balance, tone) are accomplished using digitally switched 1% resistors. Sources are switched via precision sealed reed relays similar to the ones McIntosh uses in its top-of-the-line C1000 preamp. NAD says that, along with ensuring precise control, use of these technologies means that all actual switching and adjusting components can be located optimally within the circuit, and that the analog signal doesn't need to be routed to the front panel's "virtual" controls. Careful circuit layout, short signal paths, miniature surface-mount components, and multilayered circuit boards all help contribute to NAD's claim of "infinitesimal levels of noise and distortion."
The preamp section is an all-discrete design using low-noise, high-impedance JFET buffer amps at the input and proprietary high-current, low-output-impedance, class-A gain modules. The claimed result is wide dynamic headroom, high output current, and a signal/noise ratio in excess of 100dB (IHF). The balanced XLR line input uses identical JFET buffers that feed a discrete differential amp claimed to yield common-mode rejection in excess of 80dB.
The dual-mono amplifier's power supply features custom-wound Holmgren toroidal transformers, separate unregulated and discrete-regulated supplies for various stages of the circuit, high-current rectifiers, and low-ESR (effective series resistance) filter capacitors. An independent power supply is used for the display and digital functions to help keep noise to a minimum.
"In terms of build Quality, Ergonomics, and Functionality, it seems the M3 should cost far more then a relatively modest $2799"
NAD's PowerDrive circuit continually monitors output current and adjusts the power-supply voltage rails to maximize the dynamic power sent to the speakers. According to NAD, PowerDrive makes the M3 sound far more powerful than its rated 180Wpc. (For a detailed explanation of PowerDrive, see the sidebar "What Is PowerDrive?," in Jim Austin's review of NAD's C 372 integrated amplifier in the October 2006 Stereophile
The power-amp circuit uses a wideband, current-mode, class-A voltage amplifier and an NAD-patented current amp output stage with small amounts of feedback to help deliver less than 0.002% distortion at all audible frequencies. The output stage's four pairs per channel of 150W discrete bipolar output transistors deliver 50 amps of peak output current.
Setup and use
Throughout the review period, I didn't remove the M3's jumpers to audition its pre- and power-amp sections separately, nor did I use its second-zone function, or its second-preamp output with the selectable low-pass filters for sat/sub or biamp use. Instead, I used the M3 the way I figured most Stereophile readers interested in it would: as an integrated amplifier.
Operation of the M3 was straightforward, thanks to its ergonomically pleasing remote control (it's not backlit, though the buttons do glow in the dark) and its easily legible fluorescent display. Switching among inputs and adjusting the volume, modes, and other operating parameters were handled crisply and cleanly. In terms of build quality, ergonomics, and functionality, it seems the M3 should cost far more than a relatively modest $2799. When I look back at my time with the M3, the phrase that comes to mind is "bullet-proof." And its front and rear panels also serve as handles that make lifting and installing the M3 a pleasure.
Warm and lush
Should you use a $2800 integrated amplifier to drive a $46,000 pair of Wilson Audio Specialties MAXX2 speakers or, for that matter, a $70,000 pair of Peak Consult El Diablos?
Well, why not? With its 180Wpc, the M3 should be more than capable of effectively driving, without strain, most moving-coil speakers—if not to their dynamic maximums, then at least to satisfying sound-pressure levels. Makers of expensive loudspeakers often like to point out how relatively easy their speakers are to drive, how inexpensive watts have become, and how much more you get from a marriage of expensive speakers and cheap electronics than the reverse.
"The more I listened to the M3, the more I was reminded of NAD's Original 3020 integrated. I can't think of a higher compliment."
Judging by how pleasing the Wilsons and Peaks sounded driven by the NAD M3, those speaker makers have a point. While neither pair sounded as harmonically surefooted, dynamic, and detailed as when driven by my Musical Fidelity combo of kWP preamp ($11,000) and kW monoblocks ($23,000), I know that what I heard from them with the M3 was far superior to anything I'd hear from $34,000 worth of electronics driving $2800 worth of loudspeakers. Count on it.
The biggest differences between the megawatt/buck Musical Fidelitys and the M3 were in dynamics and bass control. While the M3 could make the Wilsons or Peaks play loudly and cleanly without sounding strained, it wasn't (I assume) able to produce enough current to deliver the bass extension and control of which both speakers are capable. While the following sonic memory is almost a year old and thus perhaps unreliable, the $649 RR2150 receiver from Outlaw Audio (see my review in the March 2006 Stereophile Vol.29 No.3) dug into the Wilsons' bass bins somewhat more effectively than did the M3, though with less textural subtlety. The M3's deep-bass performance sounded generally somewhat soft, and less capable of plumbing the depths than the more powerful and more expensive audiophilegrade solid-state gear. The M3's bass performance was almost tube-like—which, depending on your perspective, is a compliment or an insult.
That said, I doubt most buyers of the M3 will use it to drive expensive, current-gulping speakers. And no, I haven't contradicted myself. I'd still prefer the M3- Wilson combo to any pairing of cheap speakers and expensive amp you might come up with. The M3's smooth, coherent top-to-bottom presentation would allow that imaginary owner of an M3 and Wilson MAXX2s to thoroughly enjoy the partnership.
The M3's top end was also somewhat lacking in extension and control ( ie, transient speed and clarity) compared to the Musical Fidelitys, but as it will more than likely be paired with lower-priced speakers not equipped with the smoothest, highest-resolution tweeters, that combo should provide excellent sound as well. With the M3-Wilson and M3-Peak combos, the NAD's softer, sweeter top worked beautifully with the softer, less extended bottom end.
In short: Driving the $46,000/pair Wilson MAXX2s, the NAD M3 was far more musically enjoyable and impressive than it had any right to be. The reason was an overall sophisticated, coherent balance that was so right that, instead of spotlighting any obvious deficiency, it fooled the ear-brain into adding what was missing. For example, had the M3 combined an iron grip and extension on the bottom with its soft, sweet top—or soft, limited extension below with fast, extended highs—either resulting sound would have been annoying: one bass-heavy and probably dull overall, the other mini-monitor thin and shrill, or tending in that direction.
Instead, the M3's overall presentation was both impressively coherent and evenhanded tonally, particularly in the all important midrange, where it sounded smooth as peach fuzz and rich and delicate as a soufflé, with neither hard edges nor lopped-off soft ones. And while the M3's overall sense of pacing was less than high-stepping, the top's velvety richness and the bottom's relative softness combined to produce a coherent rhythmic picture.
I figure that, driving a smaller speaker with limited bass response and a somewhat sizzly tweeter (a combo typical of inexpensive speakers), the M3 would, within limits, deliver performance analogous to what I heard via the Wilson MAXX2s. How swell is that?
The more I listened to the M3, the more I was reminded of NAD's original 3020 integrated. I can't think of a higher compliment. While the M3's output, build quality, and cost far exceed the 3020's, its smooth, even-keeled, slightly soft sound was as enticing, if not more so, than that of the original 3020, and leagues above that of NAD's high-value entry-level products, good as they are for the money.
The 3020 made the big splash in the audiophile community that it did not because it competed with the best audiophile gear of that era, but because, despite its limitations, it produced an involvingly musical experience rarely achieved at the price. The same can be said of the M3. I spent a few days comparing commercial CDs and CD-Rs I'd made from vinyl, playing them on a recently received Naim CD555 CD player ($28,000) and switching between the M3 and the Musical Fidelity gear. (I promise you, the Naim contributed nada to the soft or the rolled-off anywhere in or out of the audioband.) The message was consistent as relayed above; I thoroughly enjoyed listening to the M3's evenhanded presentation.
"If there's any justice, the M3, like the 3020 before it, should attain the status of audiophile legend."
The M3's dynamics were equally well balanced. Its subjectively low noise floor means that its handling of microdynamics would be exceptionally good at any price, and also meant that its less-than-explosive macrodynamic performance while powering big, difficult-to-drive speakers was easier to ignore.
The LP tracks I'd compiled on CD-R proved particularly useful. "Do I," from Warm and Wonderful (Columbia CS 8488), a luxurious-sounding Les Paul and Mary Ford album, sounded as velvety—as rich, tubey, and cushiony—through the M3 as it did through the MF gear: the sonic pictures floated convincingly free of the speaker baffles instead of snagging on bright leading edges.
The leading-edge sparkle was somewhat muted with the Small Faces' "Lazy Sunday Afternoon," and the track's astounding bass extension was a bit curtailed—but what remained struck an attractive balance of midband warmth, detail, and resolution of low-level details.
While the M3's overall dynamics didn't jump out at me when they should have, compared to an amp capable of ten times the wattage, I could hear deeply into the lowest level of musical minutiae. In "Tourist Town," from Marti Jones' Used Guitars (A&M SP 5208), the surprise kick drum near the beginning usually knocks me off my chair. Through the M3, it merely startled. On the other hand, as the opening guitar line fades into black before the kick drum, I could hear way into the decay. In other words, the longer ago I'd heard the big amps' presentation, the easier it was to accept and appreciate what the small M3 could offer.
I can already hear some of you: "It's got tone controls—why not boost the bass and treble a dB or so to get the weight and sparkle you think are missing?" I tried that. All I got were some standout sparkle, some elevated boom, and a hole poked through the M3's coherent membrane. No thanks.
NAD makes at least four integrated amplifiers that cost less than the M3. I haven't heard any of them, but I also haven't read any reviews that grant any of them the special status that seems reserved for the legendary 3020 alone.
The M3 is the first NAD integrated amplifier since the 3020 to have captured the spirit and addictive sound of that still lauded design, even as it ratchets up the levels of technology, build quality, ergonomics, overall sonic performance, and (especially) power output to the state of the art. That's why I consider it a better value than the 3020, even though, when adjusted for inflation, its price is five times as high.
It may have been unfair to test the M3 with my very expensive speakers, but it seemed appropriate, given NAD's ambitions for the product. I'm only speculating, but I'll bet the combination of the M3 and a good $7000/pair speaker would create a solid foundation for an exceptionally fine-sounding music system costing less than $15,000.
The powerful, feature-packed, superbly built M3 is easy to recommend. The combination of its smooth, sophisticated sonic balance, exceptionally silent background, overall musical coherence—and, especially, its freedom from obvious sonic glitches—produced consistently attractive and musical sound that was easy to live with. If there's any justice, the M3, like the 3020 before it, should attain the status of audiophile legend. This latest creation of Bjørn Erik Edvardsen is a work of art.
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- 2012-05-05 Hi-Fi World Champion Nominations
- 2009-04-24 Stereophile Recommends the M3 Amplifier
- 2007-10-05 Hi-Fi plus Reviews The Masters Series M3
- 2007-09-25 Editors Choice 07
- 2007-05-23 Inner Ear Reviews M3 Integrated Amplifier
- 2007-02-27 HVT Reviews M3 and M55
- 2007-02-06 Real Hi-FI
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