NAD M10 Streaming Amplifier Lab Report

Lab Report

NAD already has a deal of experience implementing Hypex's Class D nCore amplifier modules, so the M10 has more in common with the M22 [HFN Apr '15] than the 'Direct Digital' M32 [HFN Jul '18]. Rated at '100W into 8/4ohms', in practice the M10 delivers a remarkably 'stiff' 2x100W/8ohm and 2x200W/

4ohm, the comprehensively-regulated switchmode PSU actually restricting any headroom under dynamic conditions to 99W, 196W, 257W and 178W into 8, 4, 2 and 1ohm [see Graph 1, below]. All digital and analogue inputs are managed in the digital domain and finally passed to the nCore amps after D/A conversion at 48kHz/24-bit, so the response of the power amp is limited to –0.9dB/20kHz regardless of the incoming sample rate. The preamp outs, however, reach up to –0.1dB/20kHz, +0.1dB/

45kHz and +0.3dB/90kHz with 48kHz, 96kHz and 192kHz digital inputs. Jitter is very low too – less than 30psec at 48kHz/24-bit via S/PDIF or USB and typically ~10psec at higher sample rates.

The S/N is superior, relatively speaking, via the pre than the power amp outputs (the latter at 82.5dB re. 0dBW is a little below average) but distortion is impressively contained via the nCore amps. In practice these modules hold to within 0.006% over the top 1-80W of their dynamic range from 20Hz-6kHz (increasing to 0.07%/20kHz). Via digital in/pre out, distortion is as low as 0.00035% through bass and mid over the top 10dB of its dynamic range [black trace, Graph 2 below] but is uniformly higher at 20kHz over the top 30dB of its range [blue trace]. Incidentally, users should take care if employing the M10 solely as a preamp – however unlikely – because the nCore modules remain powered-up throughout. PM

819nad.lab1

Dynamic power output versus distortion into 8ohm (black trace), 4ohm (red), 2ohm (blue) and 1ohm (green) speaker loads. Max. current is 13.3A

819nad.lab2

Distortion versus 24-bit digital signal level over a 120dB range (1kHz, black; 20kHz, blue)

Continuous power (<1% THD, 8/4ohm) 100W / 200W
Dynamic power (<1% THD, 8/4/2/1ohm) 99W / 196W / 257W / 178W
Output imp. (20Hz–20kHz, Pre/Amp) 90-125ohm / 0.008-0.021ohm
Freq. resp. (20Hz-20kHz/45kHz/90kHz) –0.2 to –0.1dB/+0.1dB/+0.3dB
Digital jitter (USB / S/PDIF) 20psec / 30psec
A-wtd S/N ratio (Digital/Amplifier) 111.7dB (0dBFs) / 82.5dB (0dBW)
Distortion (20Hz-20kHz, Digital/Amp) 0.0003-0.018%/0.004–0.084%
Power consumption (idle/rated o/p) 22W/241W (1W standby)
Dimensions (WHD) / Weight 215x100x260mm / 5kg
Price £2199
COMPANY INFO
NAD Electronics International
Canada
Supplied by: Sevenoaks Sound and Vision, UK
01732 740 944
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