NAD Master 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, Björn Erik Edvardson, 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 come 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.

COMPANY INFO
NAD Electronics International
633 Granite Court
Pickering, Ontario L1W 3K1
Canada
(800) 263-4641
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COMMENTS
Matt N.'s picture

Thank you for the fantastic work you do with measurements. They have been a great tool, allowing me to narrow down the field when shopping for new products.

In Fig.5 it looks like the power output is actually 250W at 1%, not 235W. At 0.1% however it looks more like 235W. Was this a typo? Can you confirm this?

I'm using this amp to drive a pair of Revel Studio2s. My calculations tells me 235W is precisely enough to cover peaks of up to 105dB at my listening position, 9 1/5 feet from the speakers. Would you agree this amp has enough power for the Studio2s?

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