Network Audio Players/Servers

Now equipped with the MiND 2 streaming module, the 280D still employs the evergreen Sabre ES9018K2 DAC from ESS in preference to the newer 9028Q2 and 9038Q2 versions. And, credit where due, Simaudio extracts a very fine performance from this 'low consumption' DAC from the very low distortion that holds to just 0.0002% over the top 15dB of its dynamic range [see Graph 1, below] and wide 109.0dB A-wtd S/N from its standard 2.04V peak output (the single-ended RCA and balanced XLR outputs are identical). This DAC comes with three pre-installed digital filter options and Simaudio has elected to use the 'default' fast roll-off linear phase type which offers a fine 81dB stopband rejection with flat –0.2dB/ 20kHz, –0.9dB/45kHz and –2.4dB/90kHz frequency responses (48kHz, 96kHz and 192kHz, respectively) at the expense of moderately extended pre/post ripples in the time domain.

Simaudio has chosen to use slower/lower-order roll-off minimum phase filters in its costlier MOON DACs [HFN Sep '20] although the use of ESS silicon is a constant, the latter bringing with it supreme levels of jitter suppression [see Graph 2, below] – the correlated residual remaining below 8psec with 48kHz, 96kHz and 192kHz/24-bit sample rates. Because of their proprietary 'Hyperstream' architecture, ESS DACs will also usually offer very fine low-level linearity and, once again, the 109dB S/N here is sufficient to resolve signals to within ±0.3dB over a full 110dB dynamic range. Finally, Simaudio MOON's op-amp based analogue output stage bests its rated 100ohm source impedance with a lower 70ohm measured here (balanced XLR) while the methodical analogue PCB layout confers a wide 125dB stereo separation. This is all very solid stuff. PM