dCS Bartók APEX Network-Attached DAC Lab Report

Lab Report

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


Distortion vs. 24-bit digital signal level over a 120dB range at 1kHz (black) and 20kHz (blue)


20kHz/0dBFs at 192kHz/24-bit upsampled to DSD (black), DSDx2 (green) and DXD (red)

Maximum output level / Impedance 5.89Vrms / 0.5ohm
A-wtd S/N ratio (USB / Network) 117.5dB / 117.5dB
Distortion (1kHz, 0dBFs/–30dBFs) 0.00005% / 0.00009%
Distortion & Noise (20kHz, 0dBFs/–30dBFs) 0.00025% / 0.00025%
Freq. resp. (20Hz-20kHz/45kHz/90kHz) +0.0 to –0.0dB/–0.6dB/–7.1dB
Digital jitter (48kHz / 96kHz) 7psec / 8psec
Resolution (re. –100dBFs / –110dBFs) ±0.2dB / ±0.4dB
Power consumption 22W (21W standby)
Dimensions (WHD) / Weight 444x115x430mm / 16.7kg
Price £19,000 (£21,500 with headphone amp)

Data Conversion Systems Ltd
Supplied by: dCS Ltd
01954 233950