At 2 x 250 Watts, it can produce 89% efficiency, which is better than Class A according to its maker. This amp is truly digital, accepting a direct PCM input and not having to convert analog signals, deal with cable issues or an over-abundance of analog stages which can cause loss of information.  NAD collaborated with Zetex in order to take advantage of their closed-loop digital-domain error correction, and use digital feedback to eliminate drawbacks that other digital amps experienced.