SOtM sMS-200


Headphoneus Supremus
Pros: Simple, reliable, easy to configure, very good sound in stock form yet capable of reference caliber SQ with upgrades
Cons: Doesn't love handling massive libraries when used as a stand-alone server

Problem - computers are noisy, messy things. Multiple fans. Tons of background processes. Data flying every which way through a variety of system buses. The end result can be great for playing the latest first-person shooter, but not ideal for high-quality audio reproduction. Plus - have you tried fitting a PC or laptop into an audio rack? Historically, it isn't a great fit.

Solution - attack from multiple angles. Add a USB widget to clean and reclock the output. Run dedicated playback software instead of the baked-in player that came with your OS, and maybe an optimization app to help clean up the OS even further. The resulting system might be a PC running Foobar and JPLAY, plus an Uptone Regen cleaning up the outgoing USB signal. This is a pretty good solution overall, and with the right DAC can challenge some rather expensive CD players.

Downsides? Yep, a few big ones remain. Fan noise, big/ugly (or both) enclosure, and even price in many instances. You're paying for a lot more power than you need, while still not getting everything you want in other aspects. The last few generations of the Intel NUC devices solve the size issue while remaining vaguely ugly in their own way, and can still be just a tad noisy to my ears. They aren't as cheap as I'd like either. And of course sound quality on that USB output will only go so far. I guess it's fair to say that while some welcome progress has been made in this arena, a general purpose computer still isn't ideal in a high-end audio system.

If you've got lots of money to throw at the problem, a dedicated music server is the usual recommendation. Pick an Aurender, Naim, Lumin, Music Vault, Linn, Antipodes, etc, and you'll be in business. What's that? You can't (or simply won't) spend at least a few thousand dollars on this solution? Then these options are off the table. Also, many of them don't do Roon, which is absolutely essential as far as I'm concerned.

Few options remain. After trying most of them, I've found one that I absolutely love - the SOtM sMS-200. Until now I've associated SOtM with the high-end sMS-1000SQ which isn't exactly affordable, even in base form. The sMS-200 is something else though - a network audio player which sells for just $450.

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The Design
The sMS-200 is a custom built playback device with a focus on sound quality over versatility. That means just a single Ethernet input and a dedicated high-quality USB output. No wireless connection, no built-in DAC, no display, no legacy SPDIF outputs. Well, SOtM does give us a pair of USB inputs for adding storage to the system, but that's about it for extras (and I don't use those anyway). The whole point here is to send audio from point A to point B as cleanly and unobtrusively as possible. Store your library on a PC located elsewhere in the home, ship music via network over to the little SOtM for ultra-clean playback, and keep all that noise - physical and electrical - out of the listening area. All for what I consider a fairly reasonable price. What more could I ask for?

I know it's all about the sound, but looks actually do matter for a lot of us. And the sMS-200 looks quite appealing to these eyes. The enclosure is small enough to fit most anywhere, with interesting angles that set it apart from the usual audio box. At the same time it isn't really trying too hard to look "HiFi" if that makes any sense. SOtM has a whole line of other gear in the works using this same enclosure, which I feel looks superior to their prior series of small-box products.


While being very single minded in terms of hardware features, the sMS-200 does have a lot of options on the software side. SOtM runs a custom Linux build which gives a full alphabet soup of available modes: MDP, DLNA, Squeezelite, Airplay via Shairport, and HQPlayer NAA. I like having so many options but I'll be honest - I didn't really use any of those beyond testing to see if they work (they do). No, the main draw for me is Roon Endpoint capability. I run Roon server on another machine hidden in a spare room, which serves up tunes to the sMS-200 in my headphone rig. Over 100,000 tracks available, with easy setup, and smooth playback that has yet to glitch during my extensive testing. And did I mention exceptional sound quality?


Throwing the sMS-200 straight into my rig using the stock wall-wart power supply, I was very impressed with what I heard. Most of my listening was done with the Resonessence Labs Veritas DAC but I also tried out a Simaudio 430HAD, Cayin iDAC-6, Mytek Stereo 192, Esoteric D-07x, and B.M.C. UltraDAC. In each case I experienced beautiful results, with a clear edge over what I get when running straight from my PC or MacBook. The rest of the system components, for those interested: Equi=Core 1800 balanced power conditioner, Cabledyne Silver Reference cabling, Pass Labs HPA-1 headphone amp, and a bunch of headphones including HD800, LCD-3, Dharma, HE-1000, K812, and others.


With the sMS-200 in place, I get tighter low-end definition, superior imaging, and a liquidity to the treble that just isn't revealed by the more pedestrian transports. It's noticeable to the point where I'd be willing to pay some pretty good money for an improvement of that size. It was pretty clear during critical listening, but probably even more beneficial over time - music was more engaging yet natural, and therefore not as likely to induce fatigue over the long term. Kind of hard to put it into words... but I know it when I hear it, and I suspect many readers have experienced this same thing after a successful component upgrade.

The improvement was pretty consistent across the board, with the exception of the Esoteric which showed a disproportionately large jump in SQ. That particular USB implementation seems pretty sensitive to transport quality and the SOtM pushes it over the edge from mediocre to pretty good - specifically in the key upper midrange and treble area where the D-07x tends to struggle. It's still not a great DAC, despite the high price, but with the sMS-200 I'm able to enjoy it for the most part.

Let's be clear - this is not a glaringly-obvious upgrade on the same level as getting better headphones (or speakers). Swapping transducers is by far the largest upgrade one can do, followed by room treatments in the case of speaker listening (for most rooms, anyway). Those can drastically impact sound such that even a casual observer (friend, spouse, child, etc) will notice. I won't pretend the addition of a better source makes such a massive, transformative contribution to the sound.... in my experience, it just doesn't, and reviewers making such claims are exaggerating a bit. What it will do is help you get the most of the DAC you already have, along with any DAC you might try out in the future. It brings improvements in imaging, treble refinement, low end weight, and a general sense of ease I don't hear with a regular computer at the helm. So, small differences in a way, but pretty significant depending on how you look at it.

I also need to point out how different systems can be more or less equipped to take advantage of a superior source. When I run the Resonessence Labs Veritas, feeding a Pass Labs HPA-1, driving a resolving headphone like HD800 or EnigmAcoustics Dharma, I feel like the upgrade from laptop to sMS-200 is fairly obvious. Most people could probably pick up on it after a bit of serious listening with familiar material. Switching to my Cayin iDAC-6 running in tube mode to the Cayin HA-1A MK2, and driving a Sennheiser HD650... the difference is less obvious. This is still a very enjoyable system but the emphasis is more on tonal density and harmonic richness than soundstage or microdetail. I wouldn't be surprised if most people wouldn't notice the upgrade, or at least not without really straining to hear the difference. Personally, I still find the SOtM more convincing, but it's admittedly a smaller improvement and not as important in the grand scheme of things.

So, having established these aspects, I'll now submit that the convenience, size, and looks of the little SOtM still make it worthwhile to me - even in a system where the SQ improvement is modest. Fitting a laptop into either of my audio racks is not ideal. Neither is laying a big tower PC sideways. And most computers get louder than I'd like - I'm very sensitive to fan noise. Also worth noting is the fact that neither my MacBook or my PC sold for anywhere near $450 when new. For that money, the sMS-200 covers all the bases, without any extraneous functionality that isn't needed in this context. I call that a success.

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Quick Comparisons
Based on my somewhat limited testing, I do find the sMS-200 preferable to the Sonore Sonicorbiter SE and microRendu, though I'm not confident enough to get into specifics on those comparisons. Aesthetics is an obvious win for SOtM, but I think it takes a very slight edge in sonics as well. The microRendu comes very close but sounds a little "boxed in" by comparison, for lack of a better term. Again, I can't go too much deeper into this, other than to say the SOtM would be my first choice after considering sound, price, and appearance.

I've spent time with Auralic's Aries streamer in the past, though not at the same time as the SOtM. The Aries strikes me as a different animal - the emphasis is on its large feature set rather than the core sound (which is still pretty enjoyable, don't get me wrong). When running as a Roon endpoint I'd take the sMS-200 every time. If I wanted to use a different mode and play straight from the device itself, sans Roon, I think the Aries is probably better equipped to parse a massive library. The SOtM does fine in MPD mode with a sensible music collection but did stumble when trying to parse several terabytes worth. But again, I haven't done enough testing to really flesh this out fully.

The Aries Mini doesn't have Roon, so it's off my list entirely. Too bad. That would make an interesting comparison considering the similar pricing.


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So far so good, but what if we want to take things a bit further? As is often the case with all things audio, power supplies matter. A lot. For those with a suitably resolving system, replacing the bundled wall-wart is an obvious path forward.

As I write this, SOtM is still putting the finishing touches on their matching PSU. You can get their older mBPS-d2s battery-based power supply and from what I've read it works just fine, but the aesthetics are off compared to the sMS-200. Since the "correct" PSU isn't done yet I went in a different direction and tried the new PS-1 from Wyred 4 Sound.

I'll have a full write-up on the PS-1 soon enough (EDIT: here it is), but to sum it up - this is a modular design that accommodates up to four add-on cards, each capable of running at a different voltage. In my case I used their high-current module to power the sMS-200, as it draws too much juice to be used with the standard amp module. (EDIT: I've confirmed that the Standard amp module is perfectly adequate when using the sMS-200 as a Roon endpoint. Using it in MPD mode with attached hard drives might still need the High Current module, but Roon mode is fine with the regular/more affordable module).

The other typical tweak for these things involves adding a device to help clean up the USB output. For this I used a Wyred 4 Sound Recovery, powering it with another separate module inside the PS-1. Now, the sMS-200 is already quite good in terms of USB output, but I was trying to stretch its legs and see just how far it can go. The answer? Surprisingly far.

Let's tally - sMS-200 is $450, Wyred 4 Sound PS-1 is $399, plus a high-current card at $500 and a standard card at $125, and don't forget the little Recovery at $199, for a grand total of $1,673. Not at all what I'd call cheap, yet still far from the big leagues - my Aurender is $3,499 and my B.M.C. goes for $5,780. Could the souped-up SOtM, no longer a compact/simple add-on device, really compete at that level?

It sure can. I was shocked to hear the sMS-200 keep up with these far more expensive options. The linear power plus the USB treatment really brought things up several notches - again, it takes a high-end system to showcase this, but it's definitely there under the right circumstances. There are some areas where the SOtM gives ground here or there but generally speaking it is not left behind by the more expensive devices, and in some ways even surpasses them. That's highly impressive for a package costing well under half as much.

To flesh that out a bit more - the SOtM/Wyred package brings superior imaging and a more three-dimensional soundstage when used with a system capable of showcasing those traits. This was most obvious when using HD800 or my Stax rig, and even more so when I threw it in my speaker setup. Bass weight improved as well, yet it was the openness of the sound that really sold me on the impact of the PSU upgrade.

My speaker setup uses a BMC UltraDAC and a pair of Merrill Audio Thor monoblocks, driving Usher Dancer Mini One DMD speakers with their extremely revealing diamond tweeters. I normally run the BMC PureMedia as transport along with their PureUSB1 active USB cable, and it sounds beautiful. Switching to the SOtM/Wyred shifted the focus to a more ethereal presentation with improved depth and three dimensionality, at the cost of some midband richness and perceived "oomph". To use cliches, the PureMedia could be called a more stereotypically "analog" presentation, while the SOtM/Wyred rig made a more detailed, open sound commensurate with digital-done-right. Which one you prefer comes down to your taste and associated equipment. I'm just impressed to find them so evenly matched given the price disparity. If the upgraded sMS-200 can keep up with my BMC and Aurender, I have no doubt it would do the same when compared to other streaming devices I've experienced in the $2k to $6k range, and likely beyond.

Again, I have to stress that some DACs showcase the power supply and USB treatment improvements more than others, so results may vary... but in most every case I tried, there was at least some improvement over the basic sMS-200 sans extras. Which itself was, as I said earlier, already an improvement over the MacBook Pro.

While I'd happily put my Resonessence Labs and BMC reference DACs up against any sonic competition, I have to admit I find myself envious of devices from PS Audio (and others) which have built-in Roon-ready network streaming. That removes the need for another component in the chain, potentially saving quite a bit of money along with the space and system complexity required for a separate component.

That's why I'm pleased to see a well executed device like the SOtM sMS-200 come to market. It basically turns any DAC into a networked device, complete with Roon and several other options, for under $500. The sound is excellent even in stock form, the appearance is highly agreeable, and it doesn't take up much space either. I quite happily recommend this little thing in stock form.

If the user has a desire for even better sound, the sMS-200 scales wonderfully with power supply and USB output upgrades. Those on a limited budget are free to add one thing at a time, netting incremental upgrades until the final destination is reached. Did I mention the end result punching way above what the price would suggest? I have absolutely zero hesitation about running this thing with the Wyred 4 Sound add-ons in my reference rig, displacing much more expensive components. In fact, that's just what I've done. So long, Aurender.

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Yoram Diamand
Yoram Diamand
Hi, I had the ayre qb-9 twenty upgrade and listened to Qobuz hires straight from my PC, I got a lot of unwanted noises. Now I bought the sotm sms 200 neo se silver wire and SBooster psu. I hope it will be all as lovely as predicted. The qb-9 I bought as 24/96 a budget dac, now I am going to listen to excellent quality. Proust said to long for love is better than to consume. Silly guy.