Antipodes K50 Music Server
Review sample supplied by Ohm Audio
Retail prices in the Netherlands incl 21% VAT: 15.995 Euro
Available in black or Silver
Having reviewed several Antipodes Music Servers and having owned the CX and EX for close to two years as my references, I was excited to hear of the OLADRA project and even more so the arrival of an all-new range with the K50 as the King of the Hill.
Project OLADRA
As I explained in the original DX review in 2017 and in the successive DS Base, EX and EX+CX reviews, Mark Jenkins of Antipodes Audio takes a unique approach to the concept of Music Servers.
The approach that led to the EX and CX products comes down to two major factors: We all appreciate that the digital clock is important, but Noise and Bandwidth constraints prevent the accurate transmission of the clock data to your DAC. Noise is not a one-dimensional problem, because changing the frequency at which the noise occurs not only affects its impact on sound quality but can also be used to minimize the creation of noise nodes that are caused by overlapping noise peaks from multiple noise sources. But the project findings emphasized that bandwidth was equally important because a digital signal is a square wave that requires massive bandwidth in order to precisely define the timing of a change between a one and a zero. Antipodes addressed these matters by carefully tuning the motherboards in the relevant areas, eschewing the use of PCI- or USB extension boards and developing their own ultra-fast and low-noise power supplies.
Project OLADRA started well before the CX and EX were released, and those models came about to embody the early findings of the project. The project focused on developing music server technology to jointly optimize noise reduction and bandwidth expansion, and discover how to optimally manage the trade-offs between these objectives, confirmed by exhaustive listening tests. For instance, when filtering out noise from a signal you limit that signal’s bandwidth. That led to the quest to avoid the generation of noise in the first place rather than filtering it out later. The new K Series and S Series include the first full implementation of the OLADRA design, and they were designed using two key technologies: Interference Spectrum Management (using new insights into how to address noise generated by all active parts on the motherboard, while preserving bandwidth) and Hybrid Switched Linear power supplies.
As can be seen in the picture above, a large section of the K50’s internal space is occupied by the power supply section.
The new power supplies are neither switched nor linear and instead use elements of these two types of power supply in a novel way (achieving the speed of the best switched-mode power supplies and the low noise of the best linear power supplies) which has several large benefits, particularly in the context of digital circuits, where low noise and ultra-high bandwidth are required.
As Mark explains: “With noise, the quantum is very important, but you can do two things by shifting the frequency at which the noise occurs. First, changing the frequency changes the impact on tone and timbre. For example, noise at one frequency may result in super-tight bass, but of the sort that does not breathe and flow like the real thing. At a different frequency, it will emphasize high-frequency detail. At other frequencies, the sound can become too forward or too recessed. But second, if you have two (or more) active components on a PCB then they independently generate a spectrum of noise. The impact is dramatically worse if you allow their noise peaks to coincide – ie. you create nodes. So by shifting them so that the ‘hills’ of one coincide with the ‘valleys’ of the other, the noise floor is reduced. So the ISM technology is about how to manage the noise of multiple noise sources (active components of the circuit) for the best result and is an incredibly complex process”.
Although this still describes the OLADRA project quite superficially, I feel that it perfectly illustrates the kind of out-of-the-box thinking that makes all the difference in the seemingly simple yet treacherously complicated world of Digital Audio.
More details of the OLADRA project, a thorough explanation of how noise affects the signal and lots of other topics are detailed in the support section of the fully overhauled Antipodes website. I really urge those who are technically inclined to check it out for it makes absolutely fascinating reading.
AMS v3.0 interface
In addition to the new OLADRA platform, Antipodes has also been working on a fresh new look for their Operating System, now called AMS V3.0. With a beautiful, classy and easy to navigate “Dark-Theme” look, the local user interface is now seamlessly integrated with the external Antipodes website to make for easy switching. You could start on the Antipodes website in any browser to check out your new purchase and switch immediately to your local “My Antipodes” environment or vice versa. Alternatively, you can still reach the Web Interface by typing “myantipodes” in the search bar.
K50
The K50 is the Antipodes range-topper Music Server, containing three individual, separately powered and isolated computing devices, one computer optimized for the server part, one computer optimized for the player part and a proprietary Antipodes board dedicated to the reclocker and digital output section. With Direct Ethernet, USB, Femto Word Clock, AES2, S/PDIF on RCA, S/PDIF on BNC and I2S on HDMI, the unit is fully-equipped. The K50 is passively-cooled using a big internal heatsink, although, the word “heat” is not something I would use in relation to this server because it remains absolutely cold to the touch. When asked about this, Mark confirmed that this has nothing to do with processor throttling or any such measures but is the result of using very efficient power supplies.
Stepping down the model numbers there are the single-computer K40 “server apps only” version of the K50 that includes the range topper’s high power computation engine but no player section or digital outputs and is optimized to function as an ideal server to output isolated streams to an Ethernet DAC. Then, there’s the dual-computer K30 that contains two separately powered and isolated computation engines for server- and player functions to output via Direct Ethernet or USB and is designed to deliver a large chunk of the K50’s performance at a more affordable price.
Apart from these Big Boy Music Servers, there is also a K10 CD ripper and the four-unit modular S-series consisting of the Server+Player S40 and S30, the S60 Power Supply and the S20 Reclocker. The powerful S40 can be used equally well as a Server and Player while the S30 is great as a cost-effective Server + Player and ideal as a Player.
For this review, though, I will focus only on the K50.
System Context
The K50 will be used in the context of basically two systems: the CH Precision C1 DAC with the CH Precision A1.5 power amp driving Martin Logan ESL15A speakers, the Aqua Formula xHD DAC with V2 output board, the Audio-GD Master 1 preamp also driving the same amp and speakers and, as a special guest, the Aequo Stilla loudspeakers (review forthcoming). Interlinks used are the CH Precision Balanced Link between C1 and A1.5 and Siltech Paris between Aqua, Audio-GD and A1.5. Speaker cables are the Jorma Trinity and Driade Flow 405. For comparison, I used the Antipodes CX and EX as well as the Bryston BDP-3 network player. The preferred digital connection to the DACs in all cases was the Jorma AES/EBU cable.
Running In
I was forewarned that the power supply needs copious amounts of running in, but regardless, the K50 blew me away right from its first notes. What happens with prolonged use after about 3 weeks in is that the sound gradually becomes a little sweeter and more relaxed. Even so, one of the most overwhelming aspects that I noticed right at the beginning was just how organic the K50 sounds.
Christiaan — Thanks for the great review. I own the CX/EX combo, and am awaiting delivery of the K50 in a couple of days — very eagerly, as you might expect. I have always been impressed with Mark Jenkins’ design and engineering philosophy — he doesn’t buy into dogma, but trusts his own technical and listening skills. As a side note, I switched to using the tweaked version of LMS and squeezelite that they introduced last year — have u tried that? Sounds way better than Roon. I hadn’t thought of using Roon as the Server with Squeezelite, but it may be worth a shot. Thanks. — David
Hi David, I’ve not worked with LMS for a long time. Back when Logitech was still involved I did not like the sound too much, well not at all, actually. Where do you run the tweaked LMS version now with respect to the CX/EX? PS: if going outside of Roon then I personally prefer jRiver Media Center with UPnP for the extra-rich meta data / feature set, and this also sounds great.
Great review, thank you!
As a side note, can you list all the reviews in order, date etc will make it much easier to find reviews.
Thanks! Currently, reviews can be found by product type (amplifier/CD player, etc) from the main menu and these search results are alphabetical. You can also search by brand, see the brands cloud at the bottom of the home page or the brands list in the sidebar of each other page. The home page by default shows all articles by date. What other order specifically would you like to see?
Chris, last November, Antipodes announced new software upgrades, of which their tweaked LMS was a part. Here’s the relevant description in the email to customers:
“LMS Player.
LMS (also known as Logitech Media Server or Squeezebox Server) has always been the free option for music playback on Antipodes Music Servers. LMS has been significantly upgraded so that it is a very attractive alternative to other playback software options, and is free.
LMS has a huge range of features including streaming services, including QOBUZ, TIDAL, Radio Paradise, and a huge range of internet radio stations.
Antipodes has worked on optimising the sound quality of LMS on Antipodes Music Servers and it is now very competitive from a sound quality viewpoint.
Antipodes includes a resampling tool with LMS. One particularly useful feature is that it can play FLAC files by sending the WAV file equivalent to the renderer app, which improves naturalness compared to rendering the FLAC file. But you can also upsample and/or transcode to DSD.
One of the advantages of LMS is that the player is browser based. This means that you do not need a remote control application. The application is on the Antipodes Music Server and all you need to do is browse to it. The result is very fast response, using an application that won’t chew through your phone’s battery.”
As I mentioned in my earlier post, I ordered the K50 — it is humming away now. I noticed that the LMS has been rebranded as “Squeezeserver” (both work with the squeezplayer or squeezelite, I forget).
Worth checking out, IMHO. — David
Hi David, ah yes, of course. Well, I must confess to not having paid any attention to the Squeezeserver part. I just dismissed it without a second thought based on bad experiences long ago. Interesting what you mention about playing FLACs as WAVS. Time permitting, I may still investigate all this. Knowing that UPnP and MPD outperform Roon Server with Squeezelite, I wonder which would come out on top.
Christiaan, just one clarification. The comparison of WAV vs. FLAC belongs to Mark Jenkins — most of that post was an extended quote from his e-mail. I have no experience that isolates the 2 for comparison. Just the belief that LMS/Squeezeserver sounds markedly better than Roon. (One difference I can point out is cautionary — WAV does not display art dependably. When I was using Roon a couple of years ago, all my files were WAV, and only about half of my album covers were shown correctly. Ultimately, I used dbpoweramp to convert them all to FLAC and the problem was solved.)
On another note, I can confirm that the K50 is immediately and decisively better than the CX/EX combo, and quite stunning, after a few days of listening. I am eager to hear how much better it gets as the run in progresses. — David
Hi David, thanks for clarifying and I’m glad to hear that you are happy with your K50! Actually, it is perfectly possible to embed cover art in WAV files. I have been doing this for what feels like a decade using dB Poweramp, and besides embedding the metadata just to support those apps that do not read the embedded data properly, I also have set dB Poweramp to always place a cover art file in the root of the album folder called “Folder.jpg”. This covers it 100% in all the playback solutions that I have tried. I suspect that if it works unreliably for you then it is probably a matter of changing some settings.
Thanks, Christiaan. All my files are flac now, so the issue is moot. I’ll pass along one interesting tidbit/trivia Mark mentioned about flac, when I first got the CX/EX. I’m not sure I am describing it correctly, but the gist of it is that flac has some kind of parity checking built in — something that works against inevitable errors that creep in over time in magnetic storage media, that wav does not have. I haven’t verified (nor claim to really understand its working), and if someone other than Mark Jenkins mentioned it, I wouldn’t bother noting it. Archival storage is rarely discussed, but with more and more music libraries entrusted to magnetic media, it is an interesting question. How does one cope with the second law of thermodynamics? — David
Yes, an interesting question, indeed. However, I’m not sure if it really poses an issue due to the extra layers of correction built into the HDD/SSD storage systems as well as right in the PCM code itself.
Hi David, the K50 has sadly returned to the distributor (and I still have not recovered from that…) but I have tested LMS with Squeezelite versus Roon using the Antipodes CX via USB into the Aqua Formula xHD DAC and I agree that it sounds much better than RoonServer + RoonReady or Core Direct (bypassing RoonReady and going directly from server to USB). In fact, UPnP, MPD and Squeeze all sound better than Roon. There is some improvement when using Roon Server with Squeezelite as a player instead of RoonReady but the server part arguably puts the biggest mark on the SQ. Having done the comparison on the same machine with no cables changed, only switching between Roon and Squeeze via the web interface, we should safely be able to say that there are no external influences that could offset the results. iPeng is one of the best apps to control Squeeze but its interface is not equal to Roon. I will miss a lot of its functionality but the SQ is what matters most.
Hello Chris!
Great review, I am very happy to read it 🙂
Within a next 2-3 weeks I am going to get my example of K50 to test.
Nice!
Great review Christiaan. You really ought to get hold of a Taiko Audio Extreme and give it a listen. This K50 sounds like a game changer and would be really good to see how they tee up against one another.
Yeah, I agree. It has been on the list for some time but somehow it has not yet materialized.
Christiaan — I took a cue from your review, and tried the AES/EBU digital output on the K50. I have a different DAC and interconnect than yours, but had the same result. While the usb connection is excellent, there is a heightened sense of refinement, realistic depth of soundstage and greater resolution with the balanced hookup. Thanks for the tip. — David
Hi, i have already got k50!
So, the first impression is really good, K50 is next step, very interesting machine compare to EX-CX combo. My device is very new, also i have new SR Orange fuses, so it’s time to burning )
Nice, enjoy!
Hi – love your blog, bravo!!
I can’t afford the KS50, and am hesitating between a DX (gen 2) and an EX (without the CX).
FYI I have tried an Innuos Zenith mk3 and was favorably impressed with the sound but in Roon player mode (with my music library on a NAS). In Roon Core (music on the Innuos internal SSD), I was surprised to hear it sounded perhaps cleaner and tighter but also leaner and less sonorous/emotional to my ears.
What do you think?
Thank you!
Steph
I did review the DX (D2 v2.3) but have not compared it directly with the EX. My gut feeling would be that the DX might be better than the EX as an all-in-one solution. If you’re only using it as a RoonReady player then perhaps the EX might be better. But I’m really only guesstimating here.
There is indeed a difference between RoonReady and Core Direct sound but it depends on whether the device is also running the core or if it is a player. To my ears, a core/sever sounds tightests with Core Direct while a RoonReady player sounds tightest using RoonReady. Depending on the rest of the setup and your personal preferences, the tightness may also induce a sense of the music being leaner or less emotional.
Many thanks Christiaan for taking the time to answer, much appreciated! I am new to the world of servers/streamers (coming from initially a laptop with JRiver, that I replaced with a Raspberry Pi running Roon) and the learning curve is steep, but exciting!