Here's something new to me - a cumulative review of several components together. I've done plenty of shootouts and comparisons, but never a collection of products from different brands all working as one. This stuff just pairs so well together that I figured it made sense to write it up the way I use it on a daily basis. Because that's the truth - this has been my reference front-end for a while now. I rely on it to feed an absolute top-quality signal the various DACs coming through for review, and I feel it succeeds wildly at that goal. The gear in question: The Euphony PTS music server. Matrix Audio's X-SPDIF 2 digital to digital converter. And, anchoring both products, the Keces P8 linear power supply. This setup makes for an absurdly high quality transport, capable of punching FAR above its price class. While I admit that's probably an overused phrase, I back it up by choosing this system more often than the (several) more expensive alternatives that I own. You can't get a stronger vote of confidence than that. Before we go any farther, let's break down each component. Euphony PTS The Euphony PTS is a compact music server, roughly comparable to a Mac Mini in size, which goes for $1195. That gets you the standard power supply and a 250GB solid-state drive (larger drives available for additional cost). The design is fanless and thus completely silent - no spinning hard drives, no case fans, and no heatsink/fan unit on the processor. With an ultra-low TDP i3 Kaby Lake CPU, the PTS still has enough grunt to handle huge libraries and even multi-room audio. It's not a powerhouse gaming machine (obviously), but compares well with the current Intel NUC devices on the market... but more on that later. PTS stands for Perfectly Timed Streaming, a reference to signal integrity involved. The device runs Euphony OS which is a custom operating system built specifically for audio quality and simple-yet-powerful functionality. See their website for reasons why Euphony has an edge over the competition - I won't repeat it all here, but there are some theoretically compelling advantages involved. In practice, I can say I've experienced Euphony on several different systems, and in each case the SQ was superb.... so whatever it is they're doing, it works. Quick note: the system was initially going to be branded as the "Zenion" Euphony server, but plans have changed. That word has been dropped in favor of just calling it Euphony - likely since the software is such a key ingredient. My early device still says Zenion along the front panel, and you may have seen me reference Zenion in past threads. No hardware has changed though... it's the same device, just with different naming. The Euphony PTS system can run in several different modes: MPD is the native option, with simple and effective controls handled from any browser running on a computer, tablet, smartphone, etc. It's a well polished experience that in my opinion works better than using a dedicated app such as MPDroid (Android) or Soundirok (iOS). If MPD isn't your thing, you can do Squeezelite, which brings a variety of options including LMS endpoint and Roon endpoint. There's also HQPlayer endpoint mode for those of you running beastly desktop PCs for software upsampling. Lastly, Roon Server mode, which is the one I make use of most often. Switching back and forth between modes is easy using the web interface. The Euphony PTS doesn't have a built-in optical drive. If you're looking for a device to automate the process of ripping your CD collection and automatically tag everything for you, I suggest you look elsewhere. It also doesn't have the option of adding an internal DAC, nor any sort of SPDIF output. This is strictly a USB-based transport only. Networking is handled in what I consider the best way possible, which of course is Ethernet. Wifi is certainly convenient, but for the most reliable connection - and believe me, reliability is something you definitely want from your music server - the wired connection is king. As you can tell, the Euphony server is a very focused device, which doesn't try to cover every single option out there. What it does do, it does extremely well, but if you need ripping, wireless connectivity, and other extras, this isn't really the device for you. I was somewhat worried about the Euphony having enough power for Roon server duties. Roon has always recommended an i5-class processor for a smooth experience - especially with large libraries or when using their upsampling and other advanced features. After running Roon on the Euphony, I'd say it's not a problem. I have over five terabytes in my library at the monent, and it works as smooth as butter. I can upsample to DSD256 without trouble. Audeze calibration filters? No sweat. I can run audio to a few different rooms at the same time, and the PTS keeps trucking along without a hiccup. That's probably because the low TDP 6th and 7th gen U-series i3 processors perform on the same level as their i5 counterparts from the 4th/5th generations. The other factor is Euphony OS running extremely lean when it comes to system bloat. I'm really impressed at just how low CPU utilization can get during playback. Yes, more power would make it future-proof, and if you demand DSD256 upsampling and convolution for 10 rooms at a time... you'll need something beefier (but good luck finding a silent design at a reasonable price). If not, I'd say this is a perfect compromise in a passively cooled setup. Note that this device launched earlier in the year, prior to the latest Intel 8th-gen chips coming out. I don't know if the company intends to upgrade their offerings or what the time frame is on that. I'm basing this evaluation on what's available right this moment - future upgrades may bring improvements, but it would be speculation to discuss at this point. Matrix Audio X-SPDIF 2 Next up, the latest Matrix digital to digital converter. The original X-SPDIF was a fairly competitive offering for its time, but never really stood out in a sea of worthy alternatives. It offered good value but wasn't trying to take the performance crown. Things are different this time around. Matrix went all out to make the X-SPDIF 2 something special, able to compete with some of the top models on the market while keeping a relatively low price ($379). I already made a thread about it here which gives further info about the design, so I won't spend a ton of time repeating that info. Quick summary though - the X-SPDIF 2 has the usual coaxial, optical, and AES outputs, plus the increasingly popular I2S over HDMI output. The bottom of the device has DIP switches to (hopefully) allow matching to your I2S-capable DAC, since this format is not at all standardized yet. Power can optionally be provided from an external source - Matrix claims anything from 6V to 9V will work, but I've also successfully used 5V without any trouble. The big draw for me is that Matrix sounds so damn good even running directly from USB, without additional power source. Connected via USB only, I find it very competitive with my former favorite, the Singxer SU-1. Keep in mind the Singxer has a nicely done internal power supply. That Matrix can match that level of performance using pedestrian USB power is a big accomplishment. Building on that performance, the Matrix gets even better with a quality PSU in the chain. Which brings me to the third item of this collection.... Keces P8 The Keces P8 ($599) linear power supply is the backbone of this system, bringing two already excellent performing devices to a stratospheric level of performance. I wrote a bit about it here so again, I won't repeat myself all that much. In that initial write-up, I mentioned how the P8 is conceptually similar to the Wyred 4 Sound PS-1, which is an expandable modular power supply. I covered the PS-1 over at Digital Audio Review - I quite enjoyed that device and gave it a solid recommendation. Since then, I've heard some grumblings from readers who claim Wyred 4 Sound never actually finished the high-current cards. Orders were taken, but they didn't ship due to last minute changes to the design. I can't say whether or not that's true, or if the situation has been resolved, but the Keces P8 might be an alternative for some people if the PS-1 didn't work out. Keces only offers two power outputs rather than four, and voltage is not adjustable for each individual amp card, but the total output is 8A which is more than the PS-1 can muster. So whether the issue is delays or just maximum power draw, the Keces might work out better for some users. Note that my P8 has a single output option (plus the 1A USB port), so don't be confused by pics. There's essentially a blank spot on my chassis, which would otherwise have the additional output on units which have that option. Together The magic of this system really happens when bringing all three pieces together. The Euphony PTS performs quite well on its own, as does the Matrix, but when powered by the P8.... it's a whole different animal. The system as a whole sells for a bit less than $2200. That's certainly not cheap, but neither is it all that expensive compared to a lot of high-end music servers/streamers. Over the past few years I've owned or extensively auditioned the Aurender X100L ($3499), BMC PureMedia ($5390), SOtM sMS1000SQ ($4650), Esoteric N-05 ($6500) and a bunch of others ranging from $3K to a bit over $10k. The Euphony/Matrix/Keces system is significantly more affordable than any of those, and sounds superior in my book. It certainly lacks some options as I mentioned earlier, but for extracting the maximum performance out of whatever DAC you pair it with.... this is the system to choose. I'm immensely satisfied by how well the trio performs with the various DACs I have on hand. Just when you think you've heard the best your DAC has to offer, something like this comes along and unlocks even higher levels of performance. More clarity. More impact. More expansive, layered soundstage. More precise imaging. I honestly thought I was maxed out already, but clearly I was wrong. The Euphony paired with Matrix and Keces pushes performance to a level previously unheard of - having tried a fairly large portion of the competition, I'm comfortable with that statement, though of course I haven't heard everything out there. I'm especially impressed at how this little system compares with those crazy-expensive CD transports that still exist on the market. I've had models here from EMM, dCS, CEC, MSB, and MBL (weird, all three-letter names, I never noticed until now....) and none of them came anywhere close to what I get from this little ragtag system. Granted those models are often optimized to work with matching DACs from the same brand, so in some cases I didn't hear their full potential. Still, in the context of my own system, the Euphony was easily the better choice. I do have to stop here and caution readers that this is in fact "reviewer speak". The improvements I just mentioned are tangible in the right system, but I won't pretend this is on the level of switching to better headphones/speakers. Once you've got a capable transport and DAC, no amount of upgrades will be as big as upgrading transducers, or for that matter optimizing your space with room treatments. So please don't expect transformative night-to-day improvements from an upgrade like this. I wouldn't want someone with a Chord Mojo and a pair of K712s to run out and buy this system. That just doesn't make sense. That said, in a top level system, the improvement can be very worthwhile. It seems that higher-performance DACs are the ones which benefit most from this setup. My reference, the Resonessence Mirus Pro, certainly shows the difference. Finally, a Roon-ready playback system capable of matching the superb sound made by the Mirus Pro's integrated SD Card playback engine. I've been torn between the superior sound of SD playback and the usability of Roon... but now I can have both. I also hear the difference when using excellent DACs such as the BMC UltraDAC, Wyred 4 Sound DAC-2v2SE 10th Anniversary Edition, Resonessence Labs Veritas, Playback Designs MPD-5, and exceptional vintage models like the Accuphase DC-101 and Sonic Frontiers SFD-1 mkII. All of these elevate to "best ever" status when paired with the trio - I have never heard these DACs sound better. Other DACs I have on hand show a more modest improvement. This vaguely correlates with price, but not always. The Yulong DA9, Esoteric D-07x, Cayin iDAC-6, Oppo 105, and Calyx Femto can all show the difference between this trio and the Aurender X100L, but it takes critical listening and a good bit of patience to hear it. Considering the relatively low price of the trio, it might still be a worthwhile switch to make... or not. Depends on how content you might be with your current setup. For someone just starting out though, it's an obvious choice - and I say that as a long-time fan of the Aurender brand who still holds them in very high regard. Most DACs I've tried seem to do best over AES/EBU. Coaxial is the old standby, and always a solid choice, while Toslink is.... something I don't typically use. It's generally fine but I just don't usually bother with it considering the other options available. When possible though, the I2S connection is the best route. The PS Audio Stellar Gain Cell DAC ($1699) via I2S connection joins the far more expensive DACs I mentioned two paragraphs ago, in terms of improvement compared to the Aurender. The mighty Wyred 4 Sound Anniversary DAC also flies highest via I2S - it's already killer via AES, but I2S the icing on the cake. If your DAC supports I2S, it's a no brainer format choice. It is possible to use the Euphony directly via USB output. It sounds great - in a few cases, it might even sound better than using the X-SPDIF 2, depending on the DAC. Some devices do their best work via USB and in those cases you wouldn't need the Matrix at all. But my experience shows that most DACs do better through AES or coaxial when given a transport of this caliber. It really is case by case, and can be a bit confusing. For example, Arcam's recently discontinued D33 DAC ($3200) performs better via USB from my Surface Pro than it does using coaxial output from the Oppo 105. That made me initially think the design was just better suited for USB. But then I tried the Euphony/Matrix/Keces and discovered it actually sounded best via AES, then coaxial, then USB from the Surface Pro. Switching to a nicer USB source like the Aurender did nothing to change this order. Likewise, the Matrix X-SPDIF 2 can be used without the Euphony, and with excellent results. But it seems to be at its best work when fed a Euphony diet. Don't know why it matters so much, but it does. I even tried USB tweaks between Euphony and Matrix, like the Wyred Recovery, the BMC PureUSB cable, and the trusty UpTone Regen with matching PSU. None of these made a substantial difference, either with or without the Matrix in the chain. Neither does streaming over Ethernet to a SOtM sMS-200. This leads me to conclude that the Euphony PTS USB output is well sorted as-is, and nothing extra is really needed. As if the trio of products wasn't complex enough. Value? I've already mentioned the Intel NUC as a point of comparison. Let's discuss that briefly. Last year I bought a NUC with similar processing power as found in the PTS. I paid around $325 give or take. I then added RAM for another ~$70, and a 256GB SSD for $99. Not being a big fan of the system fan, I grabbed a passively cooled Akasa enclosure for silent operation, which came in around $100. The total system cost, after taxes and shipping, was approximately $650. That's just about half the price of the Euphony PTS system - and I'm not even counting an operating system. (Note that Euphony is available on SSD http://euphony-audio-usa.com/euphony_drives if you want to bring your own hardware. The starting point is $395 for a 256GB SSD.) The comparison is apples to oranges. The NUC works great for HTPC duty, playing movies via Plex or Kodi. I also use it to run SNES and Genesis emulators. And of course it does music playback via Foobar, JRiver, or Roon, without any issues. But in terms of SQ I find it lacking when compared to the Euphony. It's fine, but relatively speaking it doesn't bring the same level of performance to the DACs I've paired it with, resulting in diminished soundstage, coarse treble, and less realism overall. Is it worth the extra ~$600? That depends... in a mixed use system I'd probably spend the money on a Matrix X-SPDIF 2 and pair it with a NUC for overall versatility. For pure music use, the Euphony PTS absolutely justifies the cost as far as I'm concerned. Downsides? Honestly, I don't love having three different boxes in my rack, even if they are all relatively small. I don't love the fact that the Euphony PTS only comes in silver while the Matrix and Keces only come in black. None of them really match from an aesthetic standpoint. Then there's the matter of cabling... one AC cable for the Keces, then two customized output cables feeding the Matrix and Euphony. USB cable from Euphony to Matrix, plus AES or coaxial or whatever format you choose from Matrix to DAC. It's all more complex than I like, but I put up with it because of the phenomenal SQ it brings. Conclusion As mentioned, any of these devices are worthy of attention on their own. But when combined, the performance seems to be more than the sum of its parts. I have never achieved this level of transport quality at any price in the past, much less for $2200. Again, I realize that isn't cheap by any means.... I know money doesn't grow on trees, and that's a pretty big expenditure. But in a world of $4K LCD-4's, $6K DirectStream DACs, and IEMs in the several thousand dollar range, I don't think $2200 is unreasonable for an exceptionally well sorted transport system. I'll continue experimenting and reviewing other devices, but this trio will likely remain the foundation of my system for many years to come.