November 2014

Micro Zuma C.A.P.S. v3 Audio Server, JPLAY, SOtMtX-USBexp,
Audiophile PCI-E To USB Audio Card, And HDPLEX Linear Power Supply.
With be a million ways to enjoy computer audio, here's an excellent setup to enjoy the music.
Review By Jonathan Lo

Introduction: The Why and the How
Anybody who has delved into computer audio has likely gone through phases of frustration, hope, and frustration again. A large reason for such confusion is the seemingly infinite set of software and hardware combinations, not to mention program settings, which can influence the final sound. Combine that with often-conflicting user experiences and observations on the internet forums, along with unexplainable hardware and software quirks and glitches, it can be a maddening experience, enough to cause one to fantasize about throwing the computer out the window at times.

The situation is a little better for Mac users, as the hardware choices are much more limited and predictable, which can be confirmed by various audiophile companies that modify and sell audiophile servers based on the Mac Mini, for example. But what about the vast majority of people out there who use Windows? Having fully converted into computer audio around 10 years ago, with Windows no less, I can personally attest to both the evolution and aggravation involved in that endeavor. So why do this? Some may bring up reasons such as improved sound quality, but then others will chime in saying how their traditional audiophile CD transport sounds better, which often degenerates into bitter on-line battles. This is almost a moot point in my view, since it is almost impossible to properly compare traditional transport vs. computer due to the lack of "comparable" configurations and price points for two completely different approaches.

Personally, the single largest reason for enduring all the tribulations of computer audio is due to one thing: instantaneous access to your complete music collection any time in any order, even the old forgotten tracks. There is no going back, thus enter the C.A.P.S. v3 Micro Zuma, the "how" of the journey.

Micro Zuma vs. Via Nano Netbook vs. Silent Windows XP Server

Those who follow computer audio are likely already familiar with C.A.P.S. (Computer Audiophile Pocket Server), designed by Chris Connaker, meant to be small, fanless Windows music server providing high-quality sound quality. They come in various size and hardware configurations, which can be replicated at home by DIY'ers by following the recipe on the website. Those who are fearful of building a computer like this themselves can buy pre-made models from vendors like Small Green Computer.

The Micro Zuma was chosen for this review because it sports the most powerful CPU (Intel i7 Haswell) in the smallest form factor without fans, which was achieved via use of copper heat pipes for cooling. Another cool feature is the use of an mSATA card for the operating system and programs, resulting in lightening-quick Windows start-up times. The package can be ordered with the SOtM audiophile PCI-E USB card for high quality USB output, and the most interesting feature is the ability to configure the server to be used with an external linear power supply, also available from Small Green Computer. If so, one can specify that an Aerospace GX16 power connector be installed on the Micro Zuma for use with the linear power supply. What's even nicer is the fact this configuration does not require the ubiquitous PICO DC-to-DC converter, so the linear power supply directly powers the motherboard without the extra step.

Micro Zuma was compared to two different audio servers in house, one being a Via Nano processor based netbook employing Windows XP, the other being a purpose-built silent music server with all hard drives removed to external location with separate power supply via eSATA connection. The audio netbook is based on the low-power-consumption Via Nano processor with larger RAM upgrade, powered by its own battery. This is a very nice, quiet, compact music server, running the simpler Windows XP OS, still felt to be the best sounding Windows by some users. Sound quality is excellent. Microsoft has stopped supporting Window XP, but as long as these XP machines are not used to surf the web, they still serve beautifully as music sources.

On the other hand, Micro Zuma is a purpose-built music server with no fans or moving parts inside, utilizing heat pipes for thermal management, with Windows 8.1 OS residing on an m-SATASSD card, all processed by the mighty Intel i-7 processor. To further make the fight unfair, the SOtM high-end USB card graces the Zuma with its mighty presence.

Using a DAC with asynchronous USB input that is self-powered by the DAC and not by the USB bus, e.g. Eastern Electric DAC Plus modified with full complement of DEXA discrete op-amps, means the computer source should not matter anymore...right? We wish computer audio was that simple and predictable, but alas, the audio gods do not make it easy for us.

Micro Zuma has a much, much quieter sonic background, allowing the space between musical notes to be much more noticeable by the lack of grungy texture present. Voices and instruments are allowed to "pop" much easier against a silent and clean background, which allows tiny micro-details and inflections to come alive and titillate the ears. Each note appears more fully developed, rich, detailed, and solid. We are not talking about thrusting false detail by tipping up certain parts of the audio spectrum, ultimately leading to long-term fatigue. It's rather the case the existing detail is allowed to be more clearly heard due to less grit, dust, and mist obscuring it. One can focus on an instrument or voice, for example, and follow its decay much longer and deeper into the background without losing the harmonic information and instrumental detail. Round one goes to Micro Zuma.

Round two with a full-size silent music server with all hard drives moved outside the case with eSATA connection and external power supply is closer than with the netbook. The music server seems to present a level of detail resolution somewhere between the netbook and Micro Zuma, an excellent sound quality really, fully competitive with many high-quality traditional CD transports, albeit with a different "mien" to how music is presented, a matter of taste almost. Micro Zuma, on the other hand, just presents another level of darker background, clarity of small intonations, and naturalness. The fact it has no moving parts, drives, or fans is a big plus, even against the music server with its "silent fans."

This is all with the stock switching power supply brick for Micro Zuma, mind you, even before the arrival of the linear power supply. 

SOtM PCIe Audiophile USB Card Versus Motherboard USB Output
SOtM USB card is a purpose-built audiophile card whose whole purpose is to output low-noise, low-jitter digital output the outboard DAC, and Micro Zuma can be ordered with the SOtM card installed. The card utilizes Ultra-low noise regulators (ULNR) for its digital, clock, and USB power circuits. Noise is further reduced by power input noise filters and PCI express slot noise filters. As if that was not enough, "Xtremely Low Jitter clock" and active noise canceller is used for the card's clock power.

Gigabyte MSH81TN inside Micro Zuma is a well-built consumer motherboard, but it has no special audiophile aspirations for its mobo USB outputs.

SOtM USB output sounds more robust, solid, and richer with almost liquid, creamy textures and instrumental tones compared to the Mobo USB output. The already-clean audio background seems to drop into darker black space. The presentation is similar to what many would call "analogue" or vinyl-like. Truth be told, many audiophiles strive for years to build their systems to sound like this.

The funny thing is, for a lot of my music selections, the Gigabyte's USB output provides a little more sheen and raw energy. Its’ output certainly sounds less refined and robust. Tonal hues are not as authoritatively deep or vinyl-like. However, it has a bit more of what I can only call "life" or raw sparkle.

SOtM card can smooth out those rough edges and as a byproduct a bit of the sparkle as well. This effect is similar to when adding more and more shielding to interconnects, for example. Having experimented with many DIY cables, I have noticed in past that more and more shielding is not necessarily better for a given system, as a sense of raw energy and "twinkle" tends to decrease as more shielding is added. One could argue, probably correctly, that RFI and EMI is giving that false sense of life, but the trick seems to be finding the right balance of the system between overly raw vs. overly smooth.

No Need For SOtM?
This story would have been nice if it stopped here, so that everyone could save some money and not require the SOtM USB card. However, as usual with all things audio and especially computer audio, things took an unexpected turn once the HDPLEX linear power supply arrived for Micro Zuma. This linear power supply transforms the sound signature coming out of the SOtM USB output. The previous observation about how the SOtM perhaps helps to smooth out some raw energy is no longer true, as singers and instruments took on an added dimension of liveliness and energy via the SOtM card, all without playing tricks with the frequency curve or chrome-plating the image outlines. One would have thought the linear power supply would make the sound even more quiet, refined, smooth, with less rawness; however, while the refinement and robustness increased, so did the sense of life. One of the major factors seems to be that the linear PS presents each note even cleaner and more separated out from the background while increasing dynamic contrasts, both macro and micro. Voices, instruments, and drums seem to rev up and down freer, as if the musician came to work after a good breakfast vs. working hungry. More dynamic freedom and clarity seem to have freed the SOtM card from the previously observed reticence, to the point that the linear power supply should be considered almost mandatory if one intends to use the SOtM card. There is definitely a fantastic synergy going on with this combination.

HDPlex Linear Power Supply Versus Switching Power Supply
After getting used to the linear power supply, going back to the stock SMPS betrays a sense of paleness and edginess. Micro Zuma with SMPS sounded great previously, but everything is relative as usual. When the power supply arrived, initially my inner alarm went off since the words "linear power supply" usually means hefty price tags in the world of "audiophile" music servers. After looking at the relatively low price tag of $295, my thoughts then questioned how good it could possibly be. Once it arrived, its hefty weight, build-quality, and overall sound quality easily exceeded previous expectations.

This linear power supply is reportedly built around a high quality R-Core transformer, Linear Technology LT1083 low dropout positive fixed regulators, and ELNA capacitors to provide low ripple and noise. There are no super exotic custom regulators, silver wiring, or Teflon film capacitors in site, but solid, sensible parts have been wrought together in a solid chassis. What's even more useful is that it provides dual outputs, 19VDC and 12VDC, both of which can be used simultaneously. The 19VDC output powers Micro Zuma, while the 12VDC output can power any audiophile device that requires 12VDC. Aerospace GX16-2 connectors provide DC output, and conveniently, the power supply comes with different size barrel connectors to GX16 cables.

Other than the previously noted dynamic freedom linear PS supplies, both micro and macro, the other major attribute seems to be increased resolution via dropping of noise. Subjective perception is very much akin to listening to the audio system with room windows wide open to the outside vs. all windows closed. While the outside ambient noise may not have been intrusive or bothersome previously, once the windows are closed, the system's detail resolution, intimacy, and involvement go up a notch or two, and this is the power the linear power supply brings to the table. Everything takes less effort to hear, with much more richness and directness.

While the degree of difference may not be "audible-from-another-room" variety, once used to the extra clarity, refinement, and dynamics, it would be very difficult to go back to the old switching power supply brick powering the Micro Zuma and the SOtM USB card. This is hearty endorsement, since the Micro Zuma with stock SMPS already sounds better than any other computer source I have used in the past. The USB output from SOtM card powered by the linear power supply provides extremely rich, solid, detailed, and smooth voices seemingly anchored in a sea of blackness.

JPLAY Versus ASIO4ALL
There are two sides to computer audio that must be optimized for musical success: hardware and software. Micro Zuma does an admirable job on the hardware side, but some ink must be spilt regarding the software side. While the Micro Zuma ships with Windows installed, it does not come with any music software installed. It is still up to the user to test and choose the music playback software that will yield the best results. I chose Foobar due to several reasons: I am intimately familiar with its operations and sound due to years of use; it is free shareware; I have consistently preferred its sound signature over other free software programs over the years; and it supports JPLAY.

One of the ingredients that makes the Micro Zuma experience so successful is JPLAY, which is a music playback software with audiophile tweaks even in the Windows operating system and BIOS with the goal of improved sound quality. One great feature is its ability to be used as audio output engine with any playback software that supports ASIO, which means Foobar's convenient user interface can be used with JPLAY audio output, with all the Foobar playlists accessible at the touch of a button.

The older Foobar 0.8.3 version is still used here for various reasons, one of which is a certain signature of analogue-like immediacy and purity when used with the OtachanASIO compilation that is subtly different from other version of Foobar. As usual, these things are highly system and user-taste dependent, so experimenting first-hand is highly recommended.

Using Foobar 0.8.3 as the music player, under ASIO output module, either JPLAY or ASIO4ALL can be chosen with the Eastern Electric DAC Plus with DEXA discrete op-amps. Comparing them can be an ear-opening experience, especially if one is coming from the "bits are bits and everything bit-perfect sounds the same" school of thought. Going from ASIO4ALL to JPLAY was akin to turning up a photo's sharpness and contrast setting a notch, or two. All the little musical notes and soundstage cues are lit better, even into the darker corners and nooks, leading to the listener having to concentrate and strain less to hear the details. This leads to a little freer and easier listening experience as less effort is expended to "see" things clearly in all their glory. Going back to ASIO4ALL almost feels like taking off one's eyeglasses, albeit ones with mild prescription.

Immediately, the concern comes up whether the extra light results in brightness, hardness, and other unpleasantries. Carefully comparing music tracks with somewhat problematic sound quality at places, the worrisome sibilants and forward instrumentation do not result in significant extra pain. That is, while the imperfections in recordings are clearly audible, they do not strike the auditory nerve with significantly worse bite or amplification, a neat trick indeed.

JPLAY KS Versus JPLAY WASAPI
Within the JPLAY contol panel, either KS (Kernel Streaming) or WASAPI mode can be chosen. Both are bit-perfect ways to route audio bits through the operating system, expected to sound the same by some. The difference here is not nearly as great as using JPLAY vs. not using JPLAY, but still significant. At first, WASAPI is felt to sound nicer, more pleasant and rounder in presentation. There is a lovely bloom and air about the whole affair, which is definitely not a bad thing in music reproduction. Digging deeper into the music collection with subtler details and contrasts, KS pulls ahead slightly with more authoritative detail retrieval and just a sense that one is half a step closer to what's on the original master tape.

Still, the degree of difference here can be estimated to be on the order of less than 10 percent, it would seem, which is the type of difference that can easily go unnoticed. In fact, depending on the music being played, one's preference for KS vs. WASAPI can easily flip-flop. In the end, it's nice to have choices to tune the system to one's liking. There are many settings within JPLAY one can play with, and some seem to make more subjective difference than others. One should devote a good amount of time to tweak the particular system to reflect the listener's preferences, but there are no "wrong" settings in the absolute sense.

JPLAY Hibernate Mode
There is something called "Hibernate" mode within JPLAY which is an extreme playback mode, shutting down dozens of system processes and hundreds of threads in the operating system. While stripping down playback to bare minimum will inevitably reduce system noise and give the highest possible priority to music playback, the problem is that not all systems will work in hibernate mode. For example, if you have an antivirus program running, hibernate mode will most likely crash the system, which is the reason JPLAY recommends a dedicated music server. Then there are dozens of drivers and other processes that may or may not be compatible with hibernate mode, so one will not know until hibernate mode is actually tried on a given server.

Another big issue is that your computer screen will literally go blank as the graphics card is hibernated. One cannot see the playback software control panel, playlists, or anything else. The way to come out of hibernate mode is to disconnect a USB stick from the server, which is inserted before hibernate mode is activated as a "key." It does not matter what the USB stick holds at all. Obviously one main appeal of computer audio takes a hit: convenience and instant access to any music at any time. People who have dozens of playlists set up and like to jump from playlist to playlist, from song to song will feel the pain the most, whereas those who just load an entire album and listen to the whole thing will suffer the least. Luckily, foobar's keyboard shortcuts still work, so basic functions like volume, next, stop, pause, etc still could be used from the keyboard while the screen is blank. When a global hotkey for "stop" or "pause" is pressed in foobar, hibernate mode playing stops and one can see the desktop again, which helps to choose the next playlist or song before screen goes blank again.

It was hoped that hibernate mode would not make any sound quality difference due to convenience reasons above, but as luck would have it, it surely did make a difference. The difference is not massive, but it is still likely in the neighborhood of 5% to 10% improvement in terms of increased clarity, purity, and have bass tunefullness. The effect is similar to removing a high-class tube preamp from a system that does not require a preamp. The system sounds fantastic with the preamp in place, but its removal would demonstrate it was adding a small bit of veiling blur, a hint of rosy "air" in the soundstage, and a teeny roundness to basslines. Ignorance is bliss, but once heard, it is difficult to go back.

Battery Icing On The SoTM Cake
There are various products out there that can be used to power the SOtM USB card directly, bypassing the power from the mobo. The external DC jack on the SOtM card can take 6.5V to 9V DC, which can be supplied by linear power supplies or battery power supplies. SOtM itself sells an "intelligent" battery supply as well, but at $400, it costs even more than the SOtM card itself, and the bad news for strapped audiophiles is that quality linear power supplies and battery supplies tend to cost quite a bit.

The DC input jack on SOtM is a standard 2.1 mm (ID)/5.5 mm (OD) affair, and looking around the house, I found a broken computer power supply with the same jack, which was cut off and rigged up to a DSLR camera Lithium battery, which supplies 7.4V.

The effect of this simple and cheap DIY experiment is surprisingly large, with the type of change predictable from previous experiences powering USB devices from battery. Sound becomes at once both smoother yet more defined, presumably from further dropping of noise. The most appreciated effect is how it becomes easier to hear subtle inflections, textures, therefore emotions of the singer, who now takes on a more harmonically wetter and denser 3-dimensional shape in a calmer, gentler sonic backdrop.

The first time I hooked up the battery, I literally could not get ouf the seat for hours and hours listening to mesmerizing music. Battery powering the SOtM card and linear power supply powering Micro Zuma is a fabulous combination to let music just wash over the soul.

Caveats, Odds And Ends
One caveat of this audio server setup is the fact the JPLAY cannot play high resolution files when using Foobar 0.8.3. After trying every combination of settings unsuccessfully, I contacted JPLAY, and apparently this is a known issue due to the ancient Foobar 0.8.3 internal configuration. High res files can be played with more recent Foobar versions via JPLAY without any problems, and JPLAY Mini can always play hi res. Any current music playback software that supports ASIO should be able to play hi res files via JPLAY. The pros and cons of JPLAY Hibernate mode has been discussed before as well; not everyone will be able to utilize this mode. Interestingly, when battery power supply and JPLAY hibernate mode are added to the chain, the current Foobar version 1.3.3 goes through several steps of evolution sound-wise, now becoming extremely capable-sounding, still with a different sound signature from Foobar 0.8.3 but perhaps not inferior in absolute terms.

Another observation is the fact that despite using a DAC with asynchronous USB input, which is not powered by the USB cable from the computer, sound still changes significantly with different USB cables, DC cable between linear power supply and Micro Zuma, and the power cord that powers the linear power supply. There really is no proven explanation for this subjective finding, and I can even sympathize with those objectivists who will undoubtedly dismiss such results without even trying these variables first-hand. Well, I did not believe it when Sony proclaimed "perfect sound forever" with the compact disc, and I still do not believe it when someone claims "bits are bits" in computer audio.

Perhaps the largest caveat is the fact one cannot expect to drop the Micro Zuma into an existing system and automatically expect perfection, or even acceptable results at times, especially if coming from traditional CD player or transport. Basic sound signatures of traditional disc spinner tend to be very different from audio servers, especially USB-based, such that one may need to change a few cables, tubes, or even entire components in order to adjust the sound to a new balance. It is perfectly reasonable for someone to prefer one approach over the other, but among all the hardware and software choices, computer audio is definitely not plug-and-play.

What Does It All Mean?
With music playing with gorgeous sound quality, as I gaze at the Micro Zuma, linear power supply, battery, DAC, and various software and cabling chosen for maximum synergy, a sense of awe takes over. I could change one cable, one program, or one other something right now and lose this magic that is clearly present in the listening room. As wonderfully warm, clear, lithe, resolute, and lovely as the sound is, one change could ruin it all very easily.

This sentiment applies to audio in general but especially more to computer audio. The balance and synergy among hardware and software seem so fragile, so fleeting, it is utterly amazing that anybody is able to attains magic and live happily ever after. Choice is usually a good thing, but in computer audio, there seems to be almost too many choices. Why would anyone choose to endure the time and effort required to sort through the myriad of choices, in hopes of one day reaching something satisfying? The thought of setting up a one-box CD player with a simple 2-channel integrated amplifier into bookshelf speakers seems extremely enticing, especially when one is in the middle of troubleshooting some strange computer behavior.

Well, without attempting to answer the "why" for everyone involved, one can suggest the "how." While there must be a million ways to enjoy computer audio, one fabulous way is to utilize the C.A.P.S. v3 Micro Zuma with HDPlex linear power supply and JPLAY. Given the appropriate effort, this combination is capable of delivering awesomely involving, immediate, pure, rich, and detailed view into one's favorite music, and that should be a soothing thought for the weary traveler. 

Specifications & Company Information
C.A.P.S. v3 Micro Zuma with SOtM USB card
Price: $1759

HDPlex Linear power supply
Price: $295

Small Green Computer
shop.smallgreencomputer.com

JPLAY High-End Audio Player for Windows
Price: €99
Website: JPLAY.eu