Network Audio Players/Servers

Supplied here minus its headphone amplifier [HFN May '19] but enjoying the fruits of dCS's APEX upgrade to the Ring DAC array we saw launched in the flagship Vivaldi [HFN Jun '22], the Bartók now has an enhanced purpose as the brand's 'entry level' full-width digital source. While the various upsampling/format conversion and digital filter options remain unchanged, the performance advantages offered by this APEX version of the Bartók are easily 'measurable'. While the peak/0dBFs output remains at 5.89V (balanced), the output impedance is fractionally lower (from 0.7ohm to 0.5ohm) and the A-wtd S/N ratio wider (from 116.6dB to 117.5dB). Similarly, while distortion at peak output remains stupendously low at just 0.00005-0.00025% (20Hz-20kHz) the APEX upgrade sees this reduced still further over the top 30dB of the Bartók's dynamic range [see Graph 1, below] from 0.0001-0.0004% (Bartók) to 0.00003-0.0001% (Bartók APEX) at –10dBFs (20Hz-20kHz) and from 0.0002-0.0006% to 0.0001-0.0002% (–30dBFs, 20Hz-20kHz), respectively. Jitter, too, falls from 10psec to ~7psec in this APEX variant. Granted, these are very small numbers, but they are still clearly illustrative of positive, incremental change at the cutting edge of the state-of-the-art.

The impact of dCS's LPCM-to-DXD and DSD upsampling is shown in Graph 2, where the increase in ultrasonic requantisation noise, and correlated 2nd/3rd harmonic distortions (with a 20kHz/0dBFs signal), to DSD128 [green] and DSD64 [black] compared to DXD [red] is very clear. Five DSD filters are offered, Filter 1 offering a steep –6dB/83kHz rollout after upsampling from 192kHz LPCM, with Filters 2-5 reaching 76kHz, 70kHz, 33kHz and 39kHz (all –6dB re. 1kHz), respectively. PM