![]() ![]() Lenbrook, parent company of NAD and PSB, also makes Bluesound products. To the right of these are the standard digital inputs: two coaxial (RCA), two optical (TosLink), and one AES/EBU (XLR). On the MDC side - the left, when looking directly at the rear panel - is a module for analog inputs: RCA phono complete with a phono ground connector, and stereo RCA and XLR jacks. Optical and coaxial digital outputs are also standard. ![]() Fixed rear-panel features ( i.e., not MDC) include RCA and XLR stereo outputs for connection to your power amplifier, as well as two RCA outputs labeled SUBW1 and SUBW2, for connection to powered subwoofers. The first thing you need to know about the M12 is that it incorporates NAD’s Modular Design Construction (MDC), which permits some customization of its input capabilities. Actually, “preamplifier-DAC” only begins to describe the M12’s functionality. The M22’s natural companion is the Masters Series M12 preamplifier-DAC ($3499 base price, $3948 as reviewed), which measures 17"W x 5.2"H x 14.8"D and weighs 17.8 pounds. (Make sure you’re comparing apples with apples - either at 1W or rated power - when examining two models’ spec sheets.) A high damping factor of 800 (50Hz-1kHz, 8 ohms) promises good driver control and, hopefully, tight, tuneful bass. The A-weighted signal/noise ratio is 100dB at 1W output, or 120dB at the rated power output. The M22 can even supply 50A of current into 1 ohm for 1ms - it’s a real-world powerhouse. The dynamic power rating is much higher, though: 355 or 640Wpc available into 8 or 4 ohms, respectively. The Masters M22 (17"W x 4"H x 14.8"D, 19.6 pounds) is specified to deliver 250Wpc into 8 or 4 ohms, both channels driven. But that not all negative feedback is bad has been proven by recent products such as these Ncore-based amps, as well as super-expensive, great-sounding models from companies such as Boulder and Soulution. NAD claims that they have achieved 0.003% distortion at any power level, at least in part because of “an added control loop incorporating an integrator with adaptive clipping enables 20dB more feedback to be used across the audioband because of its extremely low-phase shift resulting in a dramatic reduction in distortion across the audioband.” Negative feedback has had a bad reputation in high-end circles for years, and as implemented in some earlier products, that bad rep was well deserved. We have finally surpassed the best linear amplifier technology with switching amplifiers. It is like jet propulsion - even though rocket technology goes back hundreds of years, to the Chinese, making a jet plane took a lot longer! Class-D amplifier technology is bit like that. The underlying concept of Ncore has been around for a long time - but nobody could get it to work in a practical way. While the power supply must be contoured to the requirements of the Ncore circuit, the power supply and earlier amplifier stages that drive the Ncore were designed by NAD and reflect our design values of high dynamic power and low distortion into difficult loads. Ncore is a very specific output-stage topology that is very highly optimized and can’t really be “tuned” or changed. We developed the M22 in consultation with Hypex, but with a lot of NAD’s Bjørn Erik Edvardsen’s ideas about amplifiers included in the final design. NAD’s Greg Stidsen expanded on the NAD-Hypex partnership: allows maximum dynamic power, very high current yet with very low distortion.” If you’re thinking, “Wow, an NAD-Hypex collaboration could be quite powerful!,” you’d be right. Their Masters Series M22 stereo amplifier ($2999 USD) is based on a Hypex Ncore class-D amplifier module and a “well regulated, but not too tight, custom switch-mode design. Then, to shake things up even more, along comes NAD. It’s not an overstatement to say that Hypex is shaking the amplifier world. Various Hypex modules are showing up not only in DIY circles and plate amplifiers for subwoofers, but in highly acclaimed commercial products that challenge the state of the art. There’s no question that the Hypex class-D amplifiers developed by Bruno Putzeys have a loyal following. Still, the guy with the $1000 DAC with Sabre chip aboard probably feels pretty good about what he has. I can guarantee that in the $30k product you get a much more substantial power supply and analog output stage. I know what you’re thinking, and you’re right: What matters is how the Sabre - or any chip - is implemented. You can find the same chip in products costing under $1000. Consider this: ESS Technology’s Sabre Reference ES9018 DAC chip can be found in products costing over $30,000 that are claimed to be the state of the art - and just may be. These are interesting times for an aficionado of high-end audio gear. ![]()
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