EXTENDED REVIEW: Unlike computers, music servers have but a few simple jobs to do—store, stream, and serve music. This seemingly simple task, easily accomplished by the even the doggiest of computers, is actually fraught with issues. Noise, noise, and noise being just three of them.
New Zealand-based Antipodes Audio make a line of music servers ranging from the least expensive Antipodes DS, to the mid-tier Reference Series DV Music Server, to the top of the line unit under review, the Reference Series DX. Every server in the Antipodes lineup supports PCM up to 32/384, DSD64 and DSD128. The DX offers two options for USB output depending on your DAC's USB input; if your DAC's USB input is self-powered, like the Auralic Vega which I used for this review, then you can connect to the DX's USB Audio 2.0 5v Off output thereby eliminating one potential source of noise getting into your DAC. If your DAC relies on the USB bus for power, then use the USB 2.0 Audio 5v On output.
There's also an Ethernet input which allows you to connect to network attached storage via DLNA and you can also connect a USB hard drive to the unit's USB Backup port and the DX will access and play its contents. Antipodes recommends using the DX's internal storage for best sonic results. However, the DX server is limited to 2TB of SSD storage. The stock unit comes with 1TB. So for those music lovers with large libraries, you'll have to use your NAS or hard drive to house the spillover. I'll talk about how this sounds shortly.
The Antipodes servers run on VortexBox, the free, open source Fedora-based Linux distribution that turns any computer into a music server. This means you can use your favorite UPnP/DLNA remote app for playback or the browser-based SqueezeBox Server. I preferred remote control using my iPad running the iPeng 8 app. The DX also allows you to stream from Tidal (yeah!) using the iCkStream plugin, Qobuz, Spotify, and Internet Radio. The Antipodes also support gaplass playback.
Once connected and powered on, the DX shows up on your network-attached computer as a shared device. To copy music to it, just drag and drop. The DX also includes an auto CD ripper using Paranoid-mode that saves your CDs as uncompressed Flac files. I ripped a few CDs and all of the associated metadata, including cover art, showed up.
Since the Antipodes provides very little information on the DX server, I asked my contact at Antipodes if he could provide some. Here's the response I received from Antipodes' founder Mark Jenkins:
"The parts are not necessarily special apart from the power supply design. It is a bit like a high-end speaker – the parts may not be special but how the parts work together as a system is where the value is added. "People talk about linear power supplies as if one is much the same as another. With a server most common linear power supply designs don’t sound any better than a cheap switch-mode power supply, in fact the most common designs sound worse because of where the noise is placed (in a frequency sense). And most transformer designs sound terrible if they are placed inside the server. Our actual transformer and power supply design are a critical part of the DX.
"The motherboard derives from a standard board that happens to have the mix of the chips we like, with some minor changes to onboard power supply. But the big difference with the motherboard is the way it is tuned. All chipsets generate electronic noise that will interfere in some way with the signal carrying the digital data, and the level and frequency of the noise has an audible effect on the analog output of any DAC. It is easily heard – it just does not fit with the simplistic accepted digital theory of how these things work.
"So the key to the design is how we tune the chip-set speeds across the whole server – from power supply through to output card, and the fundamental technology capability comes from the motherboard manufacturer that we work with. The insights into where we manage and place the noise for best sound are our speciality. The effect on the final outcome is very significant and swapping the standard setup of the motherboard into the DX brings the sound quality down several notches.
"The motherboard itself uses a quad-core Atom and 4GB of DDR3 RAM. But other chipset choices on the motherboard are also important. With RAM, we get people that are worried that we should use more than 4GB, but they think that more RAM is needed because they are used to bloat-ware servers (not Linux) where you need a lot of RAM because of all the activity. We could easily run our servers with 1GB of RAM given the low level of activity during playback, but the added RAM means we can cache more of the playlist in RAM for playback directly from RAM and manage the transfer from disk to RAM in a better and more consistent way, which does improve sound. Exactly how the files are placed into RAM and read out of RAM to the audio output is very important to the sound quality. In reality, in normal use, you won’t hear any difference between using 2GB and 4GB, but the extra is useful if playing during say a library rescan or ripping.
"The DX currently uses Samsung SSDs with 3D V-NAND technology, but we are always testing new drives that come onto the market. Each server is tuned to work with the particular drives used as each can generate a slightly different noise spectrum.
"We prefer to use open source software and believe in the eco-system of SqueezeBox Server and VortexBox as the best way forward (now that Logitech is out of it). It might not fit the ‘rock star’ mentality in high-end audio, but there are a number of audio firms that have got stuck in narrow technology silos by insisting on doing something on their own.
"In the end open source software is better for the customer. The software capability of our servers continues to get better, and be widely supported, with or without us. All of our customisation is at the script level. There is a lot of customisation involved, but by keeping it at the script level it can remain proprietary in a Linux license environment." Interesting, no?
The DX has an aluminum front panel and a high gloss finished metal chassis. Sitting dead center on the front is the CD slot drive, a power button underneath which is illuminated by a ring of blue when powered on, and the company's logo and "DX" printed in subtle gray on silver on right side. I connected the DX to the Auralic Vega DAC with a length of Light Harmonic Lightning USB cable. The Vega was connected to my Pass Labs INT-30A via XRLs from Kimber, and the Pass drove my DeVore Fidelity The Nines. I ran DX for a few days, including overnight, before settling down to listen.
Once everything was set up, I dragged and dropped a bunch of music from my Synology NAS to the DX. The first record I listened to was the subtly stunning Ibeyi and within the first few notes I knew, without a doubt, that this was going to be a fun review.
While I could have written this review after that record, I dug in and enjoyed myself and my music library for a few weeks. As usual, I played all maner of music and file formats including CD-quality, higher resolution PCM and DSD up to DSD256. I also streamed from Tidal's lossless streaming service. The takeaway through all of this listening was some of the most musically engaging sounds I've experienced through my reference system. The DX delivered improved sound quality in every aspect of music reproduction as compared to my MacBook Pro.
Bass was richer and fuller and the sound image was rock solid and vast where called for, delivering with pinpoint precision the location of the performers with recordings that contain such information. Miles Davis' In A Silent Way (24/176.4 HDtracks) being one example. This record begins without Miles, with the boys in the band laying out at beautifully slow yet funked up foundation. When Miles steps in, dead center, I was initially shocked at how in-the-room his trumpet sounded. The DX also allows your DAC to shine with its fullest and brightest tone colors, 0 to 60 in a snap dynamics, and as much micro detail and macro musically moving force as it can render.
Comparing the Antipodes DX to my MacBook Pro as server was rather sad since everything I've just described was delivered by the MacBook as if someone had put a filter between my music and me. Every aspect of the reproduction took a few big obvious steps back and away from the DX's stunning clarity. Let's be clear—I am not talking about hearing chair legs squeak against floors, audience members coughing (although I must admit I'm amazed at how many cannot control their coughing), or the sounds of the second violinist's indigestion. I am talking about a richer and more rewarding musical experience.
Another thing you get when you reduce noise, and I'm fairly certain that's largely what we're talking about with the DX as compared to the MacBook Pro, is a better sense of scale. Low level details become much more sonically relevant which in turn makes larger scale sonic events that much more impactful. I know we've talked about noise in terms of cables but noise is not picky or choosy. It is not only endemic to computer-based audio, it is also agnostic in terms of where it goes.
To try out external storage, I just selected my QNAP NAS from the Home menu and browsed its contents by Album. The Antipodes was connected to my network with a length of AudioQuest Cinnamon Cat. 7 Ethernet cable. While very subtle, the same music playing from the QNAP appeared to be duller, for lack of a better word, as if a much less intrusive filter than that heard with the MacBook was placed between my music and me. While the DX playing music from my NAS still outperformed the MacBook, I'd say if you want the best from the DX, use its internal storage.
Which raises the obvious question—is 1 or 2TB enough storage for your music? In very general terms, 2TBs strikes me as the minimum amount of storage one should have available in a music server, especially if you have, or plan to have, high res recordings. While my musical appetite is bigger than my budget, I still like to plan for expansion so 2TBs does not cut it for me so I'd have to rely on the QNAP's 4TBs of storage which makes me feel more at ease.
While I have reviewed other music servers including the Aurender S10, and the Aria Music Server, it has been too long since they left here to offer any kind of in-depth comparison. While both of these servers cost more than the DX, they also offer more storage albeit of the spinning disk variety. What I will say is that if you own one of those servers you should enjoy them and live happily ever after since they are great performers.
What about streaming? I connected to my Tidal account from within the iPeng app and was streaming away in CD-quality in no time. The obvious improvement in sound quality over my MacBook was as apparent as serving up stored files. Is it enough to say it simply sounded more musical? I think so but then you might feel short-changed. Using the DX as Tidal streamer, there was a clear sense of greater dynamics, a lower noise floor, and a more distinct sense of the voice of each individual in a recording. From Kendrick Lamar's latest, Jamie xx's In Colour Preview White Label, some Schubert and Bach piano music, and more. I will also note that the DX excelled at presenting the full body of solo piano music causing me to listen to lots. Bach, Schubert, Soler, and more. Nice.
In A Silent Way
I was very much impressed by the Antipodes DX from the get go. Over time, I became more and more enamored with its ability to serve up an infectiously musical signal clearly outperforming the MacBook Pro as music server. If you are looking to get the most out of your file-based playback including streaming from services like Tidal, I'd recommend putting the Antipodes DX on your A-list of servers to audition.
......... Michael Lavorgna
Thank you so much for your thorough and insightful review. You've described the sound of our servers very well: lots more detail, but all in proportion so that it just conveys the musical event better. We're grateful that you've pointed out that a laptop, while convenient, does a poor job as a music-source compared to a well-designed server. As you've theorized, noise is a major factor here, but there are many other contributing factors which we'll get into another day, rather than prattling on here.
Regarding the DX's storage: the DX is technically capable of utilizing four SSD units, for a total of 4TB storage. However, we've not been happy with the slight degradation in sound quality heard when we add the third and fourth SSDs, caused by having all four devices with the same noise footprint. For some time now, we've been conducting a thorough examination of the problem; we believe we are on the right track with technology to resolve the issue, and will eventually be able to offer a 4TB DX with sound quality and noise levels identical to the 1 and 2TB units. Given the lengthy, thorough test protocols we implement before offering any new product, we expect that it may well be a year before the 4TB unit is available.
Regarding your observation of a decrease in sound quality when playing back music from the NAS using DLNA: in general, this is true. But if you'll allow us to assist you in setup mounting the QNAP, you'll find that the difference in sound quality between the internal storage and the mounted NAS is very small -indeed, tiny. We'd be happy to help you in the setup process, just as we would with any customer; the improvement in sound quality compared to playback through DLNA is well worth the minor effort involved.
We're very pleased by this positive review, and honored to receive the Greatest Bits Award. As we expand our dealer network throughout the US, we hope that many of your readers will come to hear the immersive and enjoyable listening experience our servers provide. We're also very keen to meet many more American audiophiles when we exhibit at THE Show at Newport Beach in May.
Thank you again for your efforts!
....... Mark Jenkins, Founder & CEO, Antipodes Audio Limited