W20 Review – Very Good Sound Quality / HIFICRITIC

Aurender W20

 South Korean brand Aurender is beginning to make an impression on the UK market, particularly since it is now distributed by British digital audio specialist dCS. The W20’s versatile hard drive music store has useful basic features, but I also discovered that this top quality unit has hidden depths of connectivity and versatility. I have seen numerous Aurender models used as the playback source at many recent audio shows, avoiding the complication of external computer style NAS drives on a local network.
Highlights of this new model include the inbuilt 6TB hard drive (2x3TB units), the ultra low jitter solid state memory for selected file playback, and the low noise lithium battery power for the S/PDIF digital output.
Circuitry Costly temperature-controlled ‘oven’ high stability crystal oscillators supply the internal clock signals. It will handle numerous formats at up to 24-bit 192kHz, and the computer section is silent (no fans are required for the supply or the CPU). The large AMOLED display may be switched between track information and replay signal level; the simulated peak meters make a pretty distraction. The unit is substantially built from heavy aluminium sections, weighing a total of 19kg and incorporating noise and vibration  countermeasures. The main supply for the unit is a 100W rated switch-mode design. A flash recovery mode helps it survive supply interruption and provide a clean restart.
Although I’m used to computer sources and remote network streamers for audio data, I still needed some familiarisation to understand the W20 and its purpose. From one viewpoint it is a network-linked iPad controlled music store with output to S/PDIF with its own App; from another perspective it is a dedicated and virtually hidden, Linux programmed, low noise microcomputer optimised to replay internal audio files from massive load-and-forget stores. 

Constructed in a magnificent alloy case worthy of high end audio and matching its lofty aspirations, this contains the computer, the audio replay software, and a massive 6TB of HDD audio storage, enough for very large CD collections plus a stack of hi res downloads. Many will never need more than this, even after years of collecting and downloading. Note that there is no RAID or similar fail safe
provision; Aurender instead recommends using a network connected computer and backup drives to move and copy music files manually to maintain a working copy of the internal content on an external backup. So a little user input is important at times to
facilitate additional backup storage.
With the network connection, the Aurender can access NAS (network attached storage) drives that don’t have UPnP, controlling file handling via the App.
However, the W20 is not UPnP ready and therefore cannot access and play files from a Naim UnitiServe, for example. The home network facility is therefore purely for maintenance, file handling and control. The second computer drive is a rather smaller solid state device, though at 250MB it is still a good size component. It has the sole duty of ‘statically’ storing a selected audio file for cleaner replay to the
digital output (once selected, this music is transferred from the main store, which is then temporarily shut down to reduce noise and electrical interference).
The raison d’être of the project is to reduce electrical noise and jitter to an absolute minimum. In orderto finesse this, the final drive has an external clock input so that it may be accurately synchronised to the external matching DAC, further reducing jitter. For this review a dCS Scarlatti DAC/Master Clock combo was lent to help prove the value of this interface.
Connecting everything up required some patience, since the master clock has feeds to and from the DAC and that clock output. Meanwhile the DAC needs the specially clocked S/PDIF signal, in this connection split into left and right channels and fed over separate, balanced AES digital interfaces.
Finally, a control cable to the master clock advises 44.1kHz or 48kHz base sampling rates; it will still operate if that reference connection is absent, but at a reduced quality by the expedient of oversampling.
Nordost Odin was used for all this interface cabling.
A computer at heart, it is programmed to work automatically, for example with a USB connected accessory drive, which provides a convenient entry for loading CDs. Just load the disc and it is uploaded to the file store. Downloads to a computer (Apple or PC) may also be added to the W20 via simple file transfer instruction via a computer on the connected network. Likewise music on USB hard drives and memory sticks is automatically uploaded and may be played once in the file store. A small delay takes place while the output memory loads, and this may be set in the App so that the DAC is properly synchronised and the start of the track is not truncated.
By painstaking trial and error, every one of the special synchronisation and connection options was assessed. Without this work you would have to take the overall performance of the connected system (which was actually quite impressive) for granted.
However, we are happy to say that each link in the chain did in fact play its part. Each ‘technology improvement’ in connection and synchronisation delivered a progressive sound quality gain, giving considerable confidence in the upgrade path established by dCS for the matching connected systems. Fortunately the Scarlatti DAC/Clock system does sound very good, and the high resolution so
clearly shown made it very easy to audition the W20’s various modes and connection options. The outputs include optical S/PDIF and a USB audio function; L+R and separate L, R digital outputs are available in BNC and AES formats. 
While the W20 can be connected to a network, this function is primarily intended for the Wi-Fi file control application working on a iPad or similar.
This App is visually attractive with clean images, though the classification can be a little wayward. Music catalogue arrangement Apps appear to have their own idiosyncrasies which one is obliged to learn (hear, hear – Ed).
We got very good results with the dCS Scarlatti on full song, scoring the combination at upwards of 200 marks for overall sound quality. It sounded beautifully clear, tightly focused and well balanced, and no one could argue with that. However, a small reservation was also expressed in the listening notes. This arose when the Aurender had been disconnected from the dCS set, and the latter was under comparison tests using an alternative S/PDIF source. This session was going fine when, almost by chance, the W20 was also powered down, and we heard an audible sound quality improvement, with deeper silences, more transparency, and a general increase in communication. We would not overemphasise this observation but merely note that all operative power supplies have some effect
on system quality, and that switch-mode types tend to be more damaging than most others. Given the objectives for ultra low jitter and very lower noise for the digital audio outputs, it would be nice to see further attention paid to the power supply side for the computer section of the design.

There are some network access limitations, and a customer will need to plan for some housekeeping to make safety backup files of audio ripped to the Aurender W20, but I found the sound quality very good when fully connected to the dCS Scarlatti digital replay system, confirming the value of the separated data channels and this fully synchronised clocking ‘transport’. Build and finish is very
good and the included iPad App is attractive and essentially easy to use. Also as connected to the internet via the network, software upgrades are regular and automatic, not requiring any user attention. Incidentally a free DSD replay upgrade will arrive very soon, perhaps by the time this review is published, for which the dCS combination is also compatible, further increasing its audiophile appeal.