Disc Players

It's tempting to assume Canor's use of a triode-based analogue output stage might set the tone for the CD 2.10's 'sound' but the impact of these twin 6922 tubes (per channel) is subtle. Distortion is higher than typical from a solid-state player using the AK4490 DAC [see Pro-Ject DAC Box DS2 Ultra in HFN Jul '16 and Hegel HD30 in HFN Jan '16] but a figure of ~0.005% through mid to high frequences at its 0dBFs (peak) output of 4.08V is not especially high. In practice it's only about 10x higher than anticipated for this DAC, the increase at low frequencies being of greatest interest [see Graph 2, below]. This goes hand-in-hand with its sub-bass boost, so THD reaches 0.025% at 5Hz with a +3dB lift in response, to 0.02% at 20Hz where the lift is just +0.2dB. At lower output levels, with less stress on the tubes, distortion falls back to a very low 0.0002-0.0005% (200Hz-20kHz, re. –30dBFs). The consistency of its distortion vs. level vs. frequency has far greater subjective significance than the absolute level [see Graph 1, below]. As, I might add, does the impressive 110.5dB A-wtd S/N ratio, also unencumbered by tubes, and the vanishingly low 15psec jitter (S/PDIF and USB).

The AK4490EQ DAC includes a choice of five built-in digital filter coefficients, a mix of fast and slow roll-off linear and minimum phase types, as suggested by the 'Filter 1' to 'Filter 5' options available on the CD 2.10. However, only one digital filter type is actually used – the sharp roll-off linear phase – offering a superb 127dB stopband rejection with CD, at the expense of pre/post ripples in the time domain. There is a very slight difference in high sample rate responses, but this appears to be a function of the analogue output filter – Filter 1, –1.3dB/60kHz; Filters 2-4, –2.0dB/60kHz and Filter 5, –2.6dB/60kHz. PM