Network Audio Players/Servers

Because the Antipodes Oladra, like music library/reclocker/server solutions from Melco, Aurender, Auralic, Innuos and others, is a data storage and delivery device, any technical or subjective uplift in performance – over a conventional NAS or PC/Mac USB solution – is best inferred via an attached, third-party streaming player or DAC. Identifying any reduction in jitter or circulating RF interference from the Oladra also depends on the USB sink's jitter suppression and/or galvanic isolation, so a USB DAC with excellent data recovery/reclocking may not express a significant difference. Similarly, any DAC with its own 'baked-in' sources of jitter will not be improved by pristine digital data from an outboard source. Ironically, it is the more rudimentary USB hub-powered DAC/headphone amp solutions, like AudioQuest's original DragonFly DAC [HFN Mar '14], that provide us with the best indicator of incoming data integrity and noise on the +5V supply. In this instance while there's a useful reduction in correlated jitter over USB from 300psec (desktop PC) to 120psec (Oldara) it's the almost wholesale suppression of circulating interference (spuriae), and improvement in A-wtd S/N from 94dB to 104dB, that will exert the subjective impact [see Graph 1].

A similar 'cleaning up' was also observed with iFi Audio's NEO iDSD [HFN Mar '21] where the 550psec of ±33/66/99Hz sidebands collapsed to just 10psec [see Graph 2] with the Oladra as USB source. Despite this ~2dB reduction in uncorrelated jitter/quantisation noise no change was seen in the NEO iDSD's 4.29V peak output, minimum 0.00015% THD (re. 1kHz/–10dBFs) or 109.7dB A-wtd S/N ratio. Other USB DACs tested, including the Mytek Brooklyn [HFN Aug '17] and dCS Vivaldi One APEX, have sufficient galvanic isolation/onboard reclocking that very little difference in jitter was observed between the test PC and Oldara USB sources. Minor variations of just ±1-2psec – within the limit of measurement – were detected despite an ostensibly greater visible reduction in the finest spuriae. Every little helps... PM