I have been using my Mac as a digital transport for some time now and get spectacular results with a good USB DAC and the right software. I’ve worked through software from Pure Music, Audirvana Plus and Decibel and each change has delivered even greater sonic delights, so much so that it has got to the point where the act of putting a disc into a CD player usually only occurs when I’m reviewing a CD player or a CD. I still enjoy vinyl and have yet to find a digital source that beats it when it comes to sheer musicality but do have to remember that a Mac and even a pretty good DAC is nowhere near as expensive as an SME 20/3 turntable, van den Hul Condor cartridge and Trilogy 907 phono stage. But the latest component to take its place on my Townshend Seismic Stand has shaken the order of things to no small degree.
The Aurender S10 is a Linux based digital transport from Widealab Inc of Korea, in essence it’s a computer that is dedicated to delivering a PCM bitstream. It’s a full width component with solely digital outputs that stores music files on a 2TB hard drive but caches tracks added to the playlist on a 64GB solid state drive (SSD) prior to playback. An approach that ensures minimum noise because the HDDs are put in sleep mode to reduce vibration and electromagnetic interference when you’re listening. There aren’t to my knowledge many other file players that go this far in the quest to deliver maximum high fidelity. Most of the alternatives in this field from Linn, Naim, Olive et al are multifunctional in that they are streaming clients that access music files from a remote drive or have built in ripping capability such as the Naim HDX, they also usually have access to net radio and music services.
What makes the S10 interesting is both this dedication of purpose and the shear seriousness with which the company has approached the issue of clock induced jitter. Rather than the TCXO (temperature compensated crystal oscillators) found in the better high end transports Aurender has sourced OCXO or oven controlled crystal oscillators that reduce timing errors by a significant margin and provide extremely high stability and low phase noise for the S/PDIF outputs on the machine.
The Aurender does not work entirely alone, it needs a wired network connection so that it can be controlled with an iPad and so that you can load music onto it from a computer. It can also, it turns out be used, as a streamer for material on attached NAS drives. Aurender supplies free iPad software but not the tablet itself which is an essential part of the system, you can play what’s on the playlist without one but you can’t put anything on that list nor do more than go through it one track at a time. So you need to factor in another £399 if you don’t have one of Apple’s small tea trays.
Despite this connection it doesn’t offer internet radio nor music services like Spotify, in essence the S10 is a replacement for a CD transport that has the sonic and access advantages of a file player. Output is via SPDIF, AES/EBU and USB outputs but it is with the former options that it excels. There are no fans onboard so it’s silent in operation and build quality is on a par with other high end components at this price point, in other words extremely high and reflected in the attractive AMOLED display which can be set to show artist and track or a pair of VU meters, which seems strange as it’s not a power amp, but looks good nonetheless.
The user interface is courtesy of the proprietary Aurender app, this shows a list of the albums, artists or tracks that you have loaded. From there you search for the desired tune and add it to a playlist where the track is lined up for playback. It’s easy to select single tracks or whole albums but after a while you end up with a lot of tracks on the playlist which makes finding individual pieces harder. If you are organised of course you can make up multiple playlists to suit your listening requirements in given circumstances, or you could have playlists for each of your current favourite albums.
The app shows the bit rate and file format of each piece as it’s playing, lets you shuffle the list or play it continuously and it’s very easy to pause and go back or forwards within a song. However the folder arrangement on the tablet doesn’t always tally with what you see on the network and it has genre categories that are rather odd like ‘local’ and ‘Etc’ but if you ignore these and use the usual methods for locating songs it works pretty seamlessly. It also updates its library automatically so there’s no need to tell it that you’ve added new material as is the case with some systems.
The iOS factor
As software driven audio goes the Aurender package proved pretty stable, it stalled on me only once in several weeks and there was only one occasion when the output became noisy and required reboot. I’ve yet to find a streamer that works seamlessly at all times but they are certainly getting better. The playlist software is not as straightforward as iTunes for instance but few things are and I suspect that with practice using it would become second nature. The fact that you need an iPad is an expense but hardly a drawback, they’re quite nice things to have about the place. One concern that was voiced is that you might get stuck with a piece of hardware that ages quickly and therefore loses value. While this is a possibility the fact that the Aurender regularly updates itself means that it will keep pace with technological change for as long as the architecture is capable of supporting that change.
I used the S10 primarily with my Resolution Audio Cantata DAC but also gave it a spin with the remarkable Metrum Octave and with both converters it delivered an outstanding result. A natural, clean, warm and transparent sound that combines the tonal neutrality of digital with the solidity and presence of analogue. If you could make a record player that produced a flat response it might well sound like this, I guess master tape would be the thing to compare but I don’t have any of that nor the hardware to play it, more’s the pity.
Next to the iMac running Decibel via Vertere D-Fi USB cable, and with no other applications running, which is essentially as good as I can get this computer to sound, the Aurender is considerably more solid and realistic as well as being dramatically more engaging. Having watched a documentary about Rush recently (Beyond the Lighted Stage, top stuff if you like the band) I was inspired to rip my CD of Moving Pictures and see whether it came up to the standard of vinyl. With the Mac this was not the case, it delivered plenty of detail but didn’t really move me the way that tracks like Tom Sawyer should. The same rip on the Aurender inspired a full blown air-drum fest of the sort that really shouldn’t be practised in public. In other words it brought back the energy and thrill of the piece in no uncertain terms, making it pretty well essential to play several more pieces from the album and appreciate once more how phenomenal Neil Peart’s drumming is.
It achieves this result by delivering strong dynamics and excellent timing alongside the masses of detail that one expects from digital files. Stevie Ray Vaughan’s Tin Pan Alley illustrated just how rich and present a sound it can produce, this is an old hi-fi dem favourite so somewhat overplayed but to say that it gains a new lease of life in this machine’s hands is an understatement. It shimmers with atmosphere and you can feel it pushing the limit of the system’s ability to resolve the scale and palpability of the recording.
It pulls things out of well played pieces that I had never previously noticed, like a knock on the guitar body during Antonio Forcione’s rendition of Take 5 from A Meeting in London. The 192kHz version of which sounds incredibly real with a body and weight that produces a presence in the room that’s extremely convincing. The other thing you notice is that rather than ‘inky blackness’ the lower levels of the recording reveal a fine mist which I take to be the noise floor of the studio hardware, which makes me think that it’s probably a lot quieter than the majority of pro equipment out there. A 44/16 rip in the form of Steely Dan’s Dr Wu was given the time and space to develop and describe the shape and colour of the various instruments and voices. This classic piece turns out to have all the body and solidity that you hear on a good vinyl pressing, if you have a copy of Katy Lied that isn’t worn out. It doesn’t have quite the pace of a top notch turntable, arm and cartridge but comes pretty close, a lot closer than digital usually does. The Metrum Octave does in fact bring it into that league when it comes to pace, it doesn’t have the Cantata’s imaging skills but has that can’t turn the thing off quality that makes good analogue so addictive. What you really need is an MSB Platinum DAC IV with it, now that would be a dangerous combination.
However even using the hardly shabby Cantata the Aurender kept digging up new stuff. It’s not an instant hit by the way, like all the best components its qualities become apparent over time, the more you play the more you hear and the deeper you get into the music. Bowers & Wilkin’s Society of Sound occasionally digs out gems for its members to download and one example I found last year was Samuel Yirga’s Habasha Sessions. This is Ethiopian jazz that has a similarity to Abdullah Ibrahim but was recorded extremely well and released at 24/48. It has always sounded good but the S10 showed that it’s even better than I thought by exposing reverb on Yirga’s piano that had previously been hidden in the noise floor.
This transport does not have an obviously 'transparent' character, there is none of the midband emphasis that creates that style of sound but it is exceptionally revealing, especially of the dynamic range on offer. In this respect it lives up to digital audio’s promise to a considerably greater extent than anything else I have tried and I will have to work very hard on my Mac if it is to fill the void that this machine will leave on its departure.
Just to make sure that I wasn’t forgetting the wonder of CD I hooked up a disc spinning transport to the Cantata via the same short piece of Wireworld coaxial digital cable to make a quick comparison. The difference in detail density was enormous and most of this was low level information, it is more dynamic, has more precise imaging and better timing largely as a result of the lack of noise in the system. What was interesting however is that the disc spinner gets closer than the Mac in terms of solidity of sound, this could be a reflection of the S/PDIF connection of course so conclusions will not yet be jumped to.
I had a visit from Scott Berry with his CAD DAC during the Aurender’s tenure and was mightly pained by the fact that his remarkably fine sounding converter is so dedicated to the cause that it only has a USB input. It wasn’t until later that week that I discovered that the S10’s USB A socket can be used to stream signal out of the machine as well as take signal in! It was at this point in the proceedings that I fount out that Widealab has a blog detailing the full operational potential of its hard and software.
With build quality that is easily of a standard that you’d expect at the price and sound quality far beyond it the Aurender S10 has established a new benchmark for digital sources. There may be better digital transports in the world but I have not encountered one.
Subsequent to writing this piece the distributor for Aurender changed from Item Audio who supplied the unit to dCS and at the time of publishing the latter did not have a final price but it is expected to be in the region of £5,500.