NAD’s Classic Series C 399 Integrated Amp Delivers Masters Series Tech For Less

There aren’t many universal truths in audio, but I can think of a couple that hold up. One is that small size comes with compromise. I’m not suggesting that audio gear has to be big and bulky to be worthwhile, just that a tiny 2-way bookshelf speaker won’t sound as powerful or as grand in scale as a 6-foot-tall tower. Of course, there may be reasons why a smaller speaker will better suit your style, your room, your needs, or even your sonic preferences. There will always be a market for small speakers, but it’s hard to make them sound BIG. Sure, if you have the engineering chops, and if you can throw enough money at the problem, you might be able to deliver some surprising results. Consider KEF’s positively Lilliputian KC62 subwoofer ($1,500). It sounds great and can produce shockingly deep bass. But the laws of physics still apply. The compromise? It can’t play very loud, especially in the lowest frequencies. For about the same price, the SVS PB-3000 ($1,600) offers higher SPLs, more punch, and the kind of room-shaking power that home theater enthusiasts crave. The SVS is also nearly 11 times the size of the KEF. A second universal audio truth has to do with price. While it’s not always true that you get what you pay for — most of us have encountered some very expensive audio gear that doesn’t seem to justify its price — it is true that you pay for what you get. That is, nothing comes for free. If your amp has a beautifully-milled aluminum chassis, and a big touchscreen display, you paid for those things. I don’t think there’s anything wrong with that; sound quality isn’t the only consideration when buying a piece of gear. Physical design and the tactile experience of using a piece of equipment are perfectly valid things to appreciate and value. But for some audiophiles, understanding these truths may cause a few uncomfortable questions to lurk and linger in the back of our minds. If this amp weren’t so small and stylish, could it be more powerful? Do I really need that fancy chassis and touch-screen display? If the manufacturer had been more frugal, could I have saved some money and bought better speakers? This kind of second-guessing isn’t always helpful, but knowing your own priorities is essential if you want to avoid buyer’s remorse. For me, these are precisely the questions that were going through my mind when I first learned about the NAD M10v2 integrated amp ($2,750). Don’t get me wrong — the M10v2 seems like a great little amp. Its small form-factor will be a big part of its appeal for many people, and it is surprisingly powerful for its size (100 watts/channel). But if you don’t value having a miniature amp, you might wonder how much power you could gain if NAD didn’t have to squeeze the amp into the M10’s half-width (8.5-inch) chassis. Ah, that lovely, solid brushed aluminum chassis, with its Gorilla Glass top panel, and large touchscreen display dominating the front panel. It’s a mighty attractive piece of gear, but what if you’d rather save a few bucks? Surely you’d get more bang for your buck if NAD went with a more modest-looking, traditionally NAD-like design. If these questions resonate with you at all, then NAD has a new amp for you: the C 399 ($1,999). The C 399 is the new flagship of NAD’s Classic Series, the company’s range of high-value products that most closely represent a continuation of its no-frills heritage. Styling? It’s just fine. Build-quality and finish? Not luxurious, but good enough. Great performance at a fair price? Absolutely. The C 399 sets out to offer virtually all of the functionality of the M10v2, with more power, for less money. And the C399 even has a few tricks up its sleeve that might leave M10 owners feeling jealous. Let’s dive in.

The C 399’s 17-inch-wide chassis may not be as svelte, nor as solid as that of the M10v2. But instead of the M10’s 100 watts, the C 399 delivers 180 watts/channel into 8 or 4 ohms, with 250 watts of instantaneous power available for musical peaks. And that power comes via NAD’s HybridDigital nCore amplification (designed by Hypex), which until now has been available only on NAD’s costlier Masters Series amplifiers. Previously, Classic Series products used amplification based on Hypex’s less advanced UcD (Universal Class D) modules. Perhaps now that NAD’s top Masters Series amps have switched from nCore amplification to Purifi Audio Eigentakt technology, the company was able to trickle down the nCore amps to the Classic Series. For those keeping score, the M10v2 also uses nCore amplification. NAD describes the C 399’s HybridDigital nCore amplifier as “highly efficient and remarkably powerful,” with the ability “to produce musical transients effortlessly.” Also borrowed from the Masters Series is the C399’s built-in DAC, which is based on the 32-bit/384kHz ESS Sabre ES9028 chip — the same DAC chip used in the M10v2 and the top-of-the-line Masters Series M33 integrated amp ($5,500). NAD says that the DAC offers wide dynamic range, ultra-low distortion, and near-zero levels of clock jitter.

The HybridDigital nCore design is renowned for its wide bandwidth, flat frequency response, clean clipping behavior with instant recovery, high current capability, and stability into demanding low-impedance speaker loads. Noise and distortion are vanishingly low under all operating conditions. The minute levels of harmonic distortion are dominated by sonically benign second and third harmonics. These refinements enable the C 399 to produce neutral, distortion-free sound even at very high listening levels, with thrilling dynamics, exquisite detail, and superb portrayal of space.

— NAD

Although the C 399 seems to be going toe-to-toe with the M10v2, it can’t match the pricier amp’s streaming smarts. The M10v2 features BluOS hi-res multi-room music streaming, which includes support for dozens of streaming services, along with Apple AirPlay 2, Spotify Connect, and Tidal Connect with MQA. Out of the box, the C 399 does not offer this functionality. The M10v2 also delivers state-of-the-art automated room correction via Dirac Live, which does an admirable job of improving bass clarity, imaging, and timbral accuracy by compensating for acoustic anomalies in the user’s listening space. We’ve never seen Dirac Live on a Classic Series amp, so it should be no surprise that the C 399 comes up short here. Or does it? The ace up the C 399’s metaphorical sleeve is the optional MDC2 BluOS-D module ($549), which uses a new version of NAD’s Modular Design Construction (MDC) technology. Since 2006, NAD has used its MDC modules to add new functionality to existing components. These easily-replaceable modules have been game-changers for NAD customers, particularly with respect to AV receivers, where the rapid development of technologies like surround sound formats and HDMI features can make even a high-end receiver seem out-of-date or obsolete just a few years after its release. MDC technology allows the user to remove an old module from a product’s rear-panel slot, and replace it with a new one that instantly adds the latest features and functionality. The C 399 is the first NAD product to use the 2nd-generation MDC2 platform, which builds upon the original MDC system by enabling two-way communication between the module and the host component. The optional BluOS-D module for the C 399 is the first to take advantage of MDC2 technology, and NAD says it will be compatible with future stereo products. The BluOS-D module is equipped with Wi-Fi and Ethernet, and as its name suggests, it turns the C 399 into a BluOS streaming device. Thanks to its new two-way communication capability, the BluOS-D module can even stream music from locally-connected sources — a CD transport, for example — to other BluOS devices on the network. It’s all controlled via the intuitive BluOS app. The BluOS-D module makes the C 399 Roon Ready, and it also incorporates two-way Qualcomm aptX HD Bluetooth.

First introduced in 2006 to reduce technological obsolescence and offer unparalleled value for money, the MDC platform remains the longest-running and most successful future-proofing program in hi-fi, supporting technologies like BluOS, 4K, and HDMI in components over a decade old. Redesigned from the ground up, MDC2 builds on the success of the original MDC platform for stereo components and now supports bidirectional data protocols, which allows for a wider range of upgrade possibilities than the first-generation MDC platform.

— Cas Oostvogel, NAD Product Manager

The MDC2 BluOS-D module also adds Dirac Live room correction, and comes with a calibrated microphone. The user runs Dirac via an app, and uploads correction curves directly to the module, which can store up to five Dirac profiles for different listening positions and room conditions. Again, the two-way architecture of the MDC2 platform allows the user to apply Dirac Live room correction to all sources connected to the C399. With the BluOS-D module installed, the C 399 is once again on even footing with the M10v2 when it comes to features, but pulls ahead thanks to the inherent future-proofing afforded by the MDC2 system. (Because of its compact form-factor, the M10v2 does not have MDC expansion slots, nor user-replaceable hardware of any kind.) And thanks to its modest build, unpretentious aesthetics, and lack of a touchscreen, a module-equipped C 399 is still $200 cheaper than the M10v2.

As with every NAD amplifier, the C 399 gets the basics right: a precise volume control with accurate channel balance, low-noise circuits, and correct input and output impedances. The C 399 with its HybridDigital nCore output stage and high-resolution ESS Sabre DAC can reproduce all your digital and analogue sources to a level of excitement and refinement that is unprecedented in its class. Ever since the launch of the legendary 3020 integrated amplifier in 1978, the NAD brand has been synonymous with value and performance. The C 399 takes that reputation to a whole new level. Thanks to NAD’s innovative new MDC2 architecture, the C 399 can serve as the hub of a world-class music system today, and for many years to come.

— Cas Oostvogel

If you already have a streaming device, such as the $599 Bluesound Node (and if you aren’t interested in Dirac room correction), you can skip the BluOS-D module and spend your money elsewhere. That’s another real advantage of NAD’s modular system: it allows you to avoid paying for certain features that you don’t need. I wish that more manufacturers took this approach, particularly when it comes to DACs and phono stages in their integrated amps. That said, the C 399 does come with the aforementioned built-in DAC, plus a moving-magnet phono stage with “ultra-precise RIAA equalization, extremely low noise, and high overload margins.” The DAC accommodates a variety of digital sources via two optical and two coaxial digital inputs, plus an HDMI eARC port for playing audio from a connected TV. There are two pairs of unbalanced line-level analog inputs featuring low-noise buffer amplifiers, which “prevent sonic degradation,” according to NAD. Outputs include preamp outs on RCA, plus dual subwoofer outputs, and two sets of loudspeaker outputs. The dedicated headphone amplifier has low output impedance, making it a good match for multi-driver balanced armature IEMs, and high output voltage capability, allowing it to drive demanding high-impedance headphones. Finally, the C399 has two MDC2 slots, allowing it to gain additional functionality down the road.

NAD C 399 vs M10v2 Considerations

As you might be able to guess by now, the C 399 is a more appealing prospect to me than the smaller, less powerful, and more expensive M10v2. Yes, I do appreciate the better styling, build, and materials quality on NAD’s Masters Series products, and if money were no object, I’d certainly be willing to pay for those luxuries. But if I were shopping with my own money and I needed an amp tomorrow, the C 399 would be higher on my list. The promise of future-proofed functionality is one of the most compelling reasons to buy an NAD, and the company has a 15-year record of making good on its promise to offer upgrades to aging products. Luckily, there are some other manufacturers that seem to understand the appeal of modular hardware. McIntosh’s new DA2 Digital Audio Module adds HDMI ARC and Dolby/DTS processing to a wide variety of existing integrated amps, receivers, and preamps from the company. Schiit Audio’s flagship Yggdrasil DAC is “completely modular and fully upgradable,” allowing the user to take advantage of advancements in USB implementation, analog board design, and more. MSB’s super-high-end DACs also follow a modular design ethos, which allows for future updates, along with easier product support and repair. If you ask me, there is no other feature or technology buzzword that can make an audio product as appealing as the knowledge that it can evolve along with your needs and the changing technological landscape. NAD is one of only a few companies making reasonably-priced gear with the promise of future hardware updates, and that makes it a winner in my book. How important is upgradeability to you? Does it factor into your audio purchase decisions? Share your thoughts in the related forum thread below.

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