Slim Devices Transporter network music player

Is a high-end music server the audio equivalent of polishing a turd? I've been hearing this put-down since I first became an advocate for digitally stored audio almost five years ago. At first, the argument was that computers had no place in a listening room. Wireless music servers took care of that argument. Then the big—and valid—concern was lossy-compressed formats, but ever-cheaper digital storage made uncompressed and losslessly compressed storage a slam dunk.

Well, said the still-unconverted, you can't argue that high-end DACs don't perform better than the cents-per-thousand mass-market chips included in players and server stations. A good point, but one quickly overcome by companies like Sonos and Slim Devices, who added digital outputs to their offerings.

But when I'd mention how good my combo of Slim Devices Squeezebox and Musical Fidelity X-DAC^V3 sounded playing my Apple Lossless Compression (ALC) files, several of my audiopals would still demure. "Surely you're not suggesting that a $300 front-end can sound as good as your Ayre C-5xe universal player?" Well, perhaps not—but near enough to clearly be high-end, and more than enough to offer hours of listening pleasure.

I must not have been the only one hearing such comments, because Slim Devices has now conjured up the Transporter, which it bills as "streaming digital music with sound quality that surpasses even the most exotic compact disc players." Everything about the Transporter has been designed to pacify audiophiles, from a hard-anodized chassis of "aircraft-grade aluminum" (per Slim Devices) to its backlit remote control to its component parts and, yes, DAC.

I guess some folks will still argue that a digital file, no matter how pristinely transferred and handled, is still a turd, but I guess it's all in the ear of the beholder. After all, I have a pair of cufflinks made from coprolite: dinosaur droppings that have, through the ages, become fossilized and quite beautiful, especially when treated as semiprecious stones.

In short, you can polish a turd. Properly processed, even the most unpromising material can become a thing of beauty.

The tourist transports his own values
The Transporter uses AKM AK4396 multibit/Sigma-Delta DACs and can accept digital inputs on coaxial, optical, and BNC S/PDIF, as well as AES/EBU balanced connectors. Internally, the Transporter, like the SB3 before it, carefully manages clock signals and employs special crystal oscillators and multiple stages of "super" power regulation, based on Walt Jung's designs. A word-clock input allows the user to sync to an external clock source, and the Transporter decodes WAV, AIF, MP3, WMA, and FLAC files with 24-bit resolution at a sampling rate of 44.1kHz, 48kHz, or 96kHz.

The Transporter's CPU is a 325MIPS, eight-way, multi-threaded device with an 8MB audio buffer and SlimDSP, a software-based digital signal processor (DSP) that resides in flash memory and is loaded into fast static memory "dynamically"; ie, as needed. This isn't conventional DSP of the sort you'd find in an A/V receiver; rather, it's designed to decode compressed files on the fly so it can transmit uncompressed 24-bit PCM over the network's WiFi link.

The Transporter has single-ended (RCA) and balanced (XLR) analog outputs, as well as coaxial, TosLink, BNC S/PDIF, and AES/EBU digital outputs. Ethernet and RS-232 inputs are also included. Analog and digital signal paths are kept separate. The balanced output remains consistent, but volume can be controlled through the single-ended outputs using a combination of digital attenuation and a set of resistor jumpers mounted on the circuit board: You set the approximate maximum volume with the jumpers and fine-tune with the digital attenuation. If you don't need to tweak it much with the digital control, you should be able to vary the volume without significant data loss. (Because I was using the Transporter with several high-end preamps, I kept the digital attenuation off during my audition, but it's there if you need it.)

One of the slickest features of the Transporter is its huge, two-part display, which is nigh on infinitely configurable. I generally used the left side to monitor whatever data were playing, and dedicated the right side to the nifty faux-analog VU meters to monitor the output. It was cool, if perhaps a little pointless. On the other hand, I had no need to scroll RSS feeds, weather data, sports scores, or other information across the display, so some harmless retro-visuals certainly didn't hurt.

Smack dab in the middle of the front panel is a large control knob, the TransNav, which employs dynamic tactile feedback to rapidly scroll through and choose from tons of information, including even the longest playlist. If you don't want to operate the TransNav up close and personal, the remote control offers an equal level of domination, though it lacks the same wow factor.

What hours of transport we shall spend
The Transporter, like the SB3, is far more versatile than a survey review can cover, primarily because Slim Devices is dedicated to open source development. Company head Sean Adams is obviously an immensely talented designer, but Slim also has a fanatical community dedicated to developing plug-ins and macros for the SB3 and the Transporter. If you desire a certain function, chances are someone else has too—and may even have created it. As Adams commented, "In a sense, with open source, we have more software developers working for us than Microsoft has thrown at Vista." Visit the Slim Devices Forums for a look at the possibilities.

Also working for Slim Devices is an unusually attentive and thorough customer-service staff. Although I had already downloaded and was running the SlimServer program on my Mac for my SB3, I had a small problem getting the Transporter to shake hands with my WiFi network. Dan of customer service talked me through it with good humor and patience. Late in the review, my Transporter refused to power on when I moved it downstairs for a final once-over. I called the help line again without identifying myself. Dan and I quickly tried a hard-power-on and a software-enabled power-up, and when both proved unsuccessful, he immediately said, "Let's get that bad boy back in here, so you can have it back before next weekend."

I was impressed and a little sheepish—I'd suddenly recalled an epic cat battle that had sent the Transporter crashing to the floor a few weeks earlier. It worked after that, but I'm betting that something was loosened enough to finally lose contact when I moved the unit downstairs. My bad. Well, Huckleberry's probably, but I'm a bad cat owner for not better securing the Transporter.

Three dollars and it only transports matter?
I integrated the Transporter primarily into my main listening room's he-man rig, which included my Ayre C-5xe universal player, K-1xe preamplifier, and MX-R monoblocks, Krell Evolution 202 and Evolution 600 preamp and power amps, and Dynaudio C-4 and Vandersteen Quatro Wood loudspeakers. All of these components are capable of highlighting minor differences, let alone compromised file formats, so I didn't bother auditioning lossy MP3s or, for that matter, Internet radio, which seldom gets above 128kbps.

It's not a matter of audio snobbery, it's merely facing reality: If your digital library isn't hi-rez, you don't need a Transporter. For this reason, I wasn't particularly disturbed that the Transporter couldn't play the few files I've downloaded from Apple's iTunes Music Store. It's true that I couldn't play them because of Apple's use of Digital Rights Management, but their 128kbps quality would have eliminated them even if the crippleware "protection" of DRM hadn't already done so. The same is also true of just about any other DRM'd download I can think of—the Transporter won't play 'em and I wouldn't have wanted to.

Dreams transport us through the underside of our days
I've already explained that I had to call Slim Devices' customer support to get the Transporter up and running, but after that relatively painless introduction, my experience was pretty much set it and forget it.

Forgotten, too, were such problems as searching a multiroom, multifloor warren of music rooms for the recording I wanted to play (or refile—as if I ever worried too much about that one). If I had the recording on my music library's hard drive, it was only a quick twist of the TransNav (or a few remote button presses away. And because I could search by artist name, album or song title, or genre, I could even find things I only vaguely remembered having, which made for a constant voyage of discovery through my own music collection. I thrilled to the mutual pleasure that the Grateful Dead got out of their 12-zillionth for-the-first-time-ever exploration of "Dark Star," on Hundred Year Hall (CD, Grateful Dead GDCD 40202). I marveled at the fluidity of Glenn Gould's traversals of J.S. Bach's Goldberg Variations (CD, Sony Classical/Legacy S3K 87703) late in the evening. The first thing in the morning, I had my eyes opened by Robert Silverman's incisive account of Beethoven's Diabelli Variations (CD, Stereophile STPH017-2).

And yes, beyond the effortless musicality, I was completely satisfied with the Transporter's sound. The bass was taut, the midrange unforced, the top end smooth and extended. The Transporter wasn't simply "good for what it was"; it was good.

It's far from original to observe that a satisfying audio component will send you scrambling through your record collection with a huge grin on your face, but that's what the Transporter did—only, thanks to how easy it made searching through my organized digital archive, I didn't have much scrambling to do. There was barely a slip between thought and deed.

Of course, as a hardworking audiophile, being merely content wasn't on the agenda—at least not for long—so I compared the files I'd ripped to my Apple G5 PowerMac, played through my network and the Transporter, with the CDs I'd ripped them from, played on my reference Ayre C-5xe universal player. Hardworking indeed—I could distinguish small differences between the Transporter and the Ayre, but we're not talking night and day, just different shades of ahhhh.

The Ayre had a tad more shimmer in the upper registers, a slightly more physical presence, if you will, and noticeably more dynamic contrast than the Transporter. Was it a big difference? Until I attempted a side-by-side comparison with the Ayre, I wouldn't have anticipated much difference—nor, I suppose, would I have noticed much if I'd rested a few minutes between the A and B portions of the comparison.

Because the Ayre C-5xe provides higher resolution than the Transporter and I make my living comparing components, I'll continue to use the Ayre as my reference. But when I'm just hanging out and relaxing, I think I'd rather spend my time listening than searching for a skootch more resolution.

Transports of joy
The more significant comparison was undoubtedly that between the Squeezebox 3 feeding an external DAC and the Transporter. While I'm sure the Transporter may convince some audiophiles of the legitimacy of networked music systems, the resistance to such systems that I've experienced in the audiophile community suggests that its more natural market might be the most discerning among the folks who already own the SB3.

I'd been using Musical Fidelity's X-DAC^V3 ($999) with the Squeezebox 3 ($299) in my dedicated small-speaker listening room downstairs, so I brought that combination up to the main listening room for the comparison. The X-DAC^V3 is no slouch—it incorporates Burr-Brown's latest chipset, the DSD1792/SRC4192/3, which upsamples to 24-bit/192kHz. Add a Stereovox XV2 digital interconnect ($149), and the Squeezebox-X-DAC^V3 system costs $1447—not exactly a giant step from the $1999 Transporter.

Actually, before I tried the SB3–X-DAC^V3 combo, I did a quick comparison between the unprocessed SB3 and the Transporter. That didn't last long—as remarkable as the SB3 is for $299, John Atkinson was correct in his assessment of both an aggressive edge and congested soundstage (September 2006). No, to really polish the Squeezebox, you have to pair it with a quality DAC.

I know I sound like an übergeeky audiophile when I say that the Transporter set the music against a darker background, but all the differences between the Transporter and the SB3-XDAC^V3 system sprang from that basic difference: everything from background to foreground had less grain and noise. The signal leaped from its backdrop with far more contrast and detail.

This, of course, meant that, on the Goldbergs, I heard Glenn Gould's humming and buzzing better, too. Fair enough—it's there, and if it's there, I want to hear it (I guess). I also heard more of the acoustic in Frankfurt's Jahrhundert Halle with the Grateful Dead, which means the Transporter was more like being there. And Robert Silverman's Beethoven sounded far more dynamic through the Transporter, which is to say it sounded much more like listening to Bob than listening to a recording.

Yes, the Transporter is worth the upgrade, even from an SB3 driving a high-end DAC. Most of the time, I would have to add a disclaimer like Of course, if you have multiple digital inputs, an outboard DAC may have more functionality—but the Transporter has extra digital inputs and convenient source switching to boot.

Beam me up!
Is the Transporter for you? I suppose that depends on your reaction to the phrase high-resolution network music player. Slim Devices practically had me at hello, but many audiophiles still resist the concept.

I believe Slim Devices has done an excellent job of defusing an audiophile's resistance. The Transporter is well-built and easy to use, contains top quality parts, and accommodates just about any kind of connection an audiophile might require. It does an excellent job of wresting that last little bit of fidelity from your uncompressed music data. In fact, if you have high-resolution music files, such as your own 24/96 recordings, it will play those, too.

As good as the Transporter is at recovering information from your music files, however, the real pleasure of using it is in setting it up to be your music interface. Between Slim Devices' own canny programming and its users' network of open-source programmers, you can personalize it to a greater degree than almost any other device I have ever encountered. When I look back at the clunky interface of my first audio server, it's as if the two aren't even of the same species.

Yes, the Transporter does cost $1999, a not-inconsiderable sum. However, I suspect that we have to thank our lucky stars that Slim Devices comes from the world of computers, where folks squeeze pennies until Lincoln yelps in order to preserve market share—if the company was from the high-end audio sector, there'd be a three or a four at the beginning of that price, if not an extra zero at the end. Two grand seems a fair price for what Slim Devices delivers.

Is the Transporter perfect? If you ask me, it's pretty darn close. I'm not sure I could ask for more, but I could see a market for a Transporter that offered less. Remove its DAC and source switching for audiophiles who already have a digital processor they're in love with and you might have a product that offered all things to all comers. But what do I know? I'm the guy who was an early adopter of music networking.

I'll tell you what—if music networks are turds, the Transporter definitely polishes 'em. It makes 'em shine like crazy diamonds.

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