Network Audio Players/Servers

With its 2go/2yu network bridge/digital-to-digital converter Chord joins a very specialised group of products that includes the dCS Bridge [HFN Jun '17], Roon Nucleus+ [HFN May '18], Pro-Ject Stream Box S2 Ultra [HFN Oct '18], Melco N10 [HFN Jun '19], Innuos Statement [HFN Jan '20], Aqua LinQ [HFN Sep '20], Grimm Audio MU1 [HFN Dec '20] and Auralic Aries G2.1 [HFN Feb '21], all of which are digital signal conditioning devices with or without either onboard ripping or storage services. In Chord's two-box solution this means re-clocking and formatting data between Wi-Fi/Ethernet and local microSD storage to, in this case, USB and S/PDIF output formats.

Via the 2go network bridge, it's now possible to 'stream' over wired Ethernet to the Hugo 2 DAC/headphone amp [HFN Aug '18] where there's no observable difference in either the maximum 4.57V output, the 116.1dB A-wtd S/N ratio or THD which remains 0.0002%/1kHz and 0.0025%/20kHz. Jitter was marginally higher at 14psec (all sample rates 48kHz-192kHz), this via the Micro USB connection from 2go to the Hugo 2 [red spectrum, Graph 2 below]. Interestingly, there's an incremental gain from adding the 2yu USB-to-S/PDIF converter and driving the Hugo 2 via coax or optical inputs. The 2yu includes additional re-clocking, jitter suppression and sample rate conversion that shaves a few psec off the Hugo 2's jitter performance [black spectrum, Graph 1].

The 2yu's S/PDIF output falls a little below the 0.9-1.2V IEC-958 specification at 612mVp-p but deterministic jitter is well within the required ±20nsec window at just ±0.5nsec. Chord uses a proprietary driver that confers a very 'fast' 4.3nsec risetime with minimal ringing and overshoot, or circulating RFI, into a standard 75ohm termination [see Graph 1]. PM