Part of the fun of being an audio reviewer is to discover new gear unknown to the general public. Such a device is this DAC from Waversa Systems, a Korean manufacturer previously unknown to me. Their founder, CEO, and lead design engineer, Dr. Collin Shin, draws on 30 years’ experience in developing low-noise, jitter-canceling chips for precision medical and military applications, to design circuits that will allow the listener to be enveloped by digitally encoded music. In designing this version of the WDAC3, Shin was assisted by legendary American audio engineer and SoundStage! Network equipment-measurement engineer Bascom H. King.
At first glance you might see nothing to distinguish the WDAC3 from the many DACs now on the market: it plays PCM files of up to 24-bit word length and 384kHz sampling rate, and DSD files up to DSD128. It measures 17.3”W by 4.1”H by 13.0”D, but its contoured case makes it seem smaller. It’s not until you try to hoist its 33.1 pounds that you realize that the WDAC3 is unusually heavy for its size.
Closer examination shows the WDAC3 to be unusual in other ways. Made of aluminum with a brushed finish of silver or black, the case comprises thick aluminum panels fitted together like a Swiss watch. OK, maybe a Japanese watch (not a put-down -- have you looked at a Seiko lately?). This is audio jewelry. The WDAC3’s display, which takes up most of the front panel, uses 1900 widely spaced white LEDs to form a large matrix of dots that spells out letters and numbers. I often gripe about displays on audio gear being too small to read, but the legibility of this one is terrific -- no need to squint to read it from across the room. It looks elegant, too. The front panel’s edges and corners are gracefully rounded, and the fit and finish are spectacular.
Below the display are, from left to right, buttons for Power (actually, standby; the real power button is on the rear panel), Source, Menu, and Select. Source selects the input the DAC is connected to, while Menu displays the WDAC3’s various settings. With Select, you choose items from the menus. The WDAC3 sits on four shallow conical feet of aluminum.
The WDAC3’s modular design lets you tailor it to your needs. Basic digital-to-analog conversion is performed by two ESS Technology ES9018K2M Sabre32 Reference chips, and that’s all those chips do. To improve the quality of the single, galvanically isolated USB input, there’s an Intel field-programmable gate array (FPGA) chip customized to perform several changes on the input signal. It can convert any PCM signal to DSD256, and any DSD signal to 24/352.8 PCM; it can also upsample PCM signals to 24/1.5MHz, then downsample them to 24/384 before D/A conversion, to improve the accuracy of the data. And, of course, the WDAC3 can play signals at their original sampling rates.
The standard analog output is balanced or unbalanced, using discrete devices (50 ohms output impedance) or output transformers (150 ohms). The transformer output is described as sounding like a tubed amplifier whose tubes you never have to replace. I wondered: is this a euphonic coloration? The user can switch between the transformer and the discrete outputs, and an output gain of 100%, 75%, or 50% can be selected for the most pleasing sound.
The WDAC3 has two digital clocks, one running at 44.1kHz, the other at 48kHz. That enables the clocking of precise multiples of 44.1kHz (88.2, 176.4, and 352.8kHz) and 48kHz (96, 192, and 384kHz). While DSD rates of up to DSD128 are supported, DSD256 recordings are becoming common, and so are DACs that support them.
The basic WDAC3 Mk.II costs $8000 USD with a single USB input, but you can add features by adding plug-in modules: digital inputs, including coaxial, AES/EBU, TosLink, RJ45, S/PDIF, Bluetooth, Wi-Fi, or I2S on an HDMI connector; a headphone amplifier; and a precision clock. Ethernet input costs $600; all other modules are $400 each. My silver-finished review sample included the Ethernet and S/PDIF inputs and the precision clock, which bypasses the internal clocks. However, there’s no volume-control module -- you can’t use a WDAC3 MK.II as a system controller. The overall price with all the included modules was $9400, which made the WDAC3 one of the more expensive DACs I’ve auditioned. The standard warranty is for three years parts and labor.
The WDAC3 has separate power supplies for its analog and digital circuits: two toroidal transformers, each with duralumin isolation and independent linear circuitry. These account for a good bit of the WDAC3’s weight. As with most DACs, you’ll need to install a driver to use it with Windows.
No remote-control handset or power cord is included.
Setup and use
Risking another hernia, I hoisted the WDAC3 onto a shelf in my equipment rack. I’d planned to use an aftermarket power cord from my stash, but it turns out that a large IEC connector completely covers the main Power switch. Instead, I used a molded cable with a narrower, top-to-bottom IEC connector. Use a browser on your iPad to go to the WDAC3’s webpage, and you’ll find a remote-control app you can use from your listening seat. Nothing fancy, it merely duplicates the front-panel buttons. The actual settings appear only on the DAC’s front panel, not the app.
The WDAC3’s front panel produces a huge display, but the letters and numbers are so big that not much information can be displayed. The DAC displays a code to indicate the setting in effect, and those codes were not intuitively obvious to me. The distributor’s manual explains the codes, but even those explanations were sometimes hard to understand. After the trouble Waversa took designing a giant display, it’s ironic that an app running on a tablet could display more info by dispensing with the codes in favor of displaying a full explanation of the settings. But it wouldn’t look anywhere near as cool.
I used Clarity Cables Organic balanced interconnects to hook up the WDAC3 to my preamplifier, and a Mike Galusha USB link to connect an Innuos ZENith Mk.II STD server to the Waversa’s input. Since the ZENith server’s proprietary operating system is a variation of Linux, it doesn’t require an additional driver. The Innuos seemed a particularly good match, as it has an Ethernet output as well as a USB output, mirroring the inputs of my review sample of the Waversa. Network cables were a mixture of Cat7 and Cat6A, none of which was remotely audiophile-grade -- or audiophile-priced.
No official user manual was included, but a document with drawings and photos of the WDAC3 and a list of its features is posted at
www.waversa.com; and the US distributor provided me with a more thorough manual. I still had trouble understanding some of the concepts and settings, but maybe that’s just me.
A couple of firmware updates were released during the review period. The distributor’s manual lists several ways they can be implemented, so, lazy dude that I am, I tried the easiest. But despite the step-by-step instructions, the WDAC3 wouldn’t start up after the first update was installed. So, with coaching from the distributor and manufacturer, I downloaded the update file, then updated the files using an SD card (as used in digital cameras). This time the update took, and the WDAC3 booted up just fine. The second update was easier -- I clicked the Update button on the app and everything else was automatic. The Innuos ZENith server was connected to the WDAC3 via both USB and Ethernet, so I could switch between the two with the Source button. Was there a difference? You bet there was -- a fairly dramatic difference, in favor of the Ethernet connection.
The WDAC3 Mk.II ran barely warm to the touch. Waversa recommends 200 hours of break-in, but the WDAC3 got a lot more than that before I began listening critically. I noticed an anomaly: On a couple of occasions, after I’d used the DAC for a fairly lengthy period, it began to sound a bit rough and distorted. Putting the DAC in Standby for a few seconds, then switching back to Play mode seemed to restore the normally smooth, undistorted sound. Sofa spuds: You can do all that from the remote app without getting up. Another anomaly: Sometimes, after starting an album playing, I’d hear a burst of loud, static-like noise. Usually that went away after a few seconds; when it didn’t, switching the WDAC3 in and out of Standby fixed the problem.
I used Roon as my playback software. For the Ethernet connection, an audio endpoint called Waversa DAC3 WAP is used.
Sound
The Waversa WDAC3 Mk.II offers more data-conversion options than I had time to explore. Here I limit my remarks to the few that seemed most interesting, including the USB and Ethernet inputs.
Most servers today have USB outputs; some have only USB outputs. It’s not because USB is the best-sounding connection -- the abundance of USB enhancement products on the market attests to a need to improve the connection format’s sound quality. USB is the dominant format because it’s the fastest, enabling playback of files of the highest sample rates, and because USB is ubiquitous -- virtually every computer includes some form of USB connection.
I began listening through the USB input with no conversion options employed. First up was “Folia Rodrigo Martinez,” from La Folia 1490-1701 (16-bit/44.1kHz AIFF, Alia Vox), by early-music specialist Jordi Savall and his band. The overall sound was unusually wide open, with a soundstage that stretched seamlessly between the speakers. Because I was also reviewing a power amplifier at the same time, I’d disconnected my subwoofers, but was pleased to hear fairly deep, impactful bass, though not as deep as I hear from my 1200W subs. Savall’s viola da gamba was depicted with realistic tonality, and the band turned in a rollicking, deeply engaging, rhythmically tight performance. Percussion sprang from the noisy background, always exhibiting bloom and air around image outlines. Waversa Systems thought unconverted playback would be unpleasant, but I’ve heard much worse.
I then cued up the title track of Shelby Lynne’s Just a Little Lovin’ (DSD64/DSF, Mercury/Acoustic Sounds). In several passages I heard details I hadn’t noticed before -- always a good sign. The increased detail included Lynne’s voice, which sounded even more expressive than normal, partly due to the excellent microdynamic shadings. Bass went fairly deep, with good definition and pitch, although I still missed my subs.
The overall volume level dropped when I converted the signal to DSD256. With “Folia Rodrigo Martinez,” bass was still noteworthy if with a bit less extension and impact, but percussion seemed to move forward, becoming more prominent. Savall’s viola da gamba receded into the background and lost a smidgen of definition. Spatially, the performance was still wide open, with an immediate perspective.
Converted to DXD, “Folia Rodrigo Martinez” was much louder and, even after adjustment of volume level, displayed tons of detail. Leading-edge transients of percussion sounds popped sharply from the background; bass seemed to go a bit deeper, with more impact; and dynamics sounded more energetic, as if spring-loaded. Overall, it was a very exciting reproduction of this richly detailed recording.
In heavy rotation lately at Casa Forrester has been violinist Mari Samuelsen’s Nordic Noir (24/44.1 FLAC, Decca/Tidal), performed with her brother, the cellist Håkon Samuelsen, and the Trondheim Soloists, a sizable chamber orchestra. It’s minimalist modern music by Pärt, Arnalds, Helmersson, Bak, and others, with beautiful violin and cello playing from the siblings. Several times during the album, the dynamics and harmonics of the two solo instruments were so correct I could have been fooled into thinking I was listening to real instruments in the room. Of course, only a reviewer would say something that goofy.
One way of avoiding the sonic imperfections of USB is not to use USB at all. I switched to Ethernet -- the two-way interface present on virtually every computer. The WDAC3’s Ethernet input can play the same DSD128 and DXD files as the USB input, and it was an ear-opener. One major difference was how stringed instruments sounded -- less shrill and mechanical than USB. Of course, the Ethernet input works only if you have a server or player with an Ethernet output, and they’re not all that common at present. From the very first sound of the cascabels in “Folia Rodrigo Martinez,” the harmonic envelope of the music seemed richer, more complete, even with no conversion. Converting to DSD and adjusting the volume level brought out the differences in the initial cascabel shakes. Each sounded a little different from the others -- usually, the first and third shakes sound identical to me. Detail was ratcheted up yet another notch, clarifying the background percussion clatter -- instead of mush, it sounded like percussion instruments playing.
Magnus: Timelapse, the first track of Nordic Noir, was appropriately dark, but the tone of the solo violin had better definition than via USB, and it seemed more distinct from the orchestral violins. The performance seemed to have a bit more urgency and flow, and sounded somewhat less flat.
Comparison
PS Audio’s DirectStream DAC ($5995) also converts an input to a higher sampling rate: 20xDSD. Then it downconverts it to 2xDSD and runs it through the only filter it has: the 24dB/octave DSD output filter. Like the WDAC3 Mk.II, the DirectStream stores its program code on an FPGA, which can be changed with a firmware update. Updated firmware code is copied to a standard SD card, and read into the DirectStream when it boots up. A brand-new firmware upgrade, Redcloud, had just been loaded into the DirectStream when I performed this comparison, so the sound of the DirectStream, too, was new to me.
Through the PS Audio DirectStream, “Folia Rodrigo Martinez” sounded somewhat like the WDAC3’s Ethernet input, but with slightly more detail emerging from the busy background. Bass was extended and displayed a fair amount of information about specific drumstrokes, which are often somewhat murky. The soundstage was perhaps not as wide through the PS Audio, but seemed to have more depth information, something I’m not often conscious of. The harmonic structure of the stringed instruments sounded more like the WDAC3 through its USB input -- not surprising, as the DirectStream was plugged into the Innuos ZENith Mk.II STD server’s USB output. Both DACs had a dynamically tight, springy sound that bespoke stout, fast power supplies.
Shelby Lynne’s “Just a Little Lovin’” had deeper bass through the DirectStream, with more thump in the opening notes, and Lynne’s voice had a dense, textured finish that made her phrasing easier to follow. Instrumental tones were accurate, and at times, leading-edge transients popped out of the mix with surprising power.
Magnus: Timelapse begins quietly; after some orchestral churning, a lone violin introduces the haunting main theme. Through the DirectStream, Mari Samuelsen’s violin seemed more expressive as it soared over the orchestra, and its tone didn’t sound as bleached as it does through some other DACs.
Both DACs ranked among the best I’ve heard. I particularly liked the sound of the Waversa’s Ethernet input, and hope this connection becomes more popular on DACs and servers. The PS Audio DirectStream comes with a complete assortment of inputs, but the Waversa offers more options through its plug-in modules. Although both models are nicely finished, the Waversa is easily the best-looking DAC I’ve seen -- it’s a gorgeous component. Both DACs have very useful displays, and although the DirectStream’s color touchscreen is much smaller than the Waversa’s huge display, it tells the user a lot more. But I often need a small telescope to read the DirectStream’s screen from my listening seat.
Bottom line
The Waversa Systems WDAC3 Mk.II is beautifully designed and built, and as jewel-like as any hi-fi component I’ve seen. It has many advanced operating features, and a front-panel display that can be read from the other side of a large room. I’d heard that using an Ethernet input for your DAC could sound much better than the ubiquitous USB input, and the WDAC3 proved that to be true. Through its Ethernet input in particular, the WDAC3 Mk.II sounded as good as it looks: spectacular. Its glitches were minor and easily fixed. Easily and strongly recommended.
Associated Equipment
- Speakers -- Affirm Audio Lumination, Syzygy SLF870 subwoofers (2)
- Amplifiers -- Audio Research VT80SE, Berning ZH-230
- Preamplifier -- Audio Research LS28 line stage
- Digital sources -- Dell Latitude E6330 laptop computer running 64-bit Windows 10 Professional and Roon; SOtM sMS-1000SQ network music player with sPS-1000 power supply; QNAP TS-251 NAS; all servers and digital players connected to a PS Audio DirectStream DAC; Audiolab 8000CD CD player; Innuos ZENith Mk.II STD digital server (in for review)
- Interconnects -- Audience Au24 SX balanced, CablePro Freedom unbalanced, Clarity Cables Organic, Crystal Cable Piccolo unbalanced
- Speaker cables -- Audience Au24 SX, Crimson RM Music Link
- Power cords -- Audience powerChord e and Au24 SE LP powerChord, Blue Marble Audio Blue Lightning, Clarity Cables Vortex, Purist Audio Design Venustas
- USB links -- Audience Au24 SE, Mike Galusha
- Power conditioner -- Audience aR6-T
Waversa Systems WDAC3 Mk.II Digital-to-Analog Converter
Price: $8000 USD (Ethernet module, $600; other modules, $400 each).
Warranty: Three years parts and labor.
Waversa Systems Inc.
404 Yeongseong Ravendor, 10-9,
258-gil, Hwangsaeul-ro, Bundang-gu,
Seongnam-si, Gyeonggi-do, 13595, Korea
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发表于 2018-5-9 21:49:36
