Direct Digital NAD M2
NAD is well known for its traditional, high-quality, and relatively affordable integrated amplifiers. At this year's CES, NAD introduced a revolutionary new integrated, the M2 ($5999). NAD's Stephen DeFuria (right) told me that the M2 is what NAD calls a "Direct Digital" amplifierthere is no analog circuitry!
First, the M2 offers a wide variety of digital inputs: one S/PDIF, one AES/EBU, two coaxial, and two optical. The amp also offers two pairs of analog inputs (both balanced and single ended), which are converted to a high-resolution digital signal so the rest of the amp's many digital features can be utilized. Second, the output stage is a class-D design using technology developed by English company Diodes-Zetex, which features what NAD calls Direct Digital Feedback. This method of amplifier feedback determines any pulse error and passes this information back to the digital domain section of the amplifier where compensations can be made.
This was one of the products at the show that I felt warranted a full write-up and evaluation in Stereophilewhen I told the well-known class-D skeptic John Atkinson about the M2, he explained that not only did he agree but that his enthusiastic review will appear in the March issue of the magazine.