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Slinky SliMP3: An Affordable MP3 Stereo Component

by Nat Torkington

Like almost everybody I know, I've been dutifully ripping my CDs to mp3 files over the last few years. I have a server running FreeBSD that delivers the files through Apache::MP3 to any machine on our home network, and now my wife and I can listen to our music on our computers. So why did I balk when my wife suggested putting the physical CDs in deep storage?

Because of our stereo. Thirty gigabytes of mp3 files are fine until you actually want to listen to them in the living room. I tried a homebrew solution a year or two ago, connecting my FreeBSD machine's sound card output to the stereo's input with a very long set of cables, but none of the FreeBSD console mp3 players I could find would successfully play the mp3 files we had ripped with RealJukebox on Windows.

Figure 1 -- Slim Devices' SliMP3

Frustration be gone! In the last year several devices have entered the market that let you play mp3s through your stereo. The latest of these is the SliMP3 from Slim Devices ($250). Small (8.5 x 2.5 x 2) and elegantly black, it has but three connectors: power, ethernet, and RCA cables to your stereo. To succeed in the consumer audio space, an mp3 appliance has to exhibit this kind of simplicity and elegance in every aspect of its design.

Figure 2 -- simple connectors on the rear of the unit

Physical installation of the unit was trivial. The hardest part was finding an ethernet cable long enough to reach from the nearest hub across the living room to the back of the entertainment center. The SliMP3 FAQ specifically addresses dispensing with the cables and going for wireless; but until it becomes possible to support 802.11b and keep down the cost, the SliMP3 will continue to be cable-bound.

The hardware component of the SliMP3 is only half the picture, though. The SliMP3 speaks its own (open sourced--there's even a SourceForge project for it) protocol with a server to fetch playlists, streams, track information, etc. So you need to run a server somewhere--servers are provided for Linux, Mac OS X, Windows, and (to my exquisite delight) there's even a Perl server. I installed the Perl server in minutes on my FreeBSD box.

Because of the various ways people set up their networks, configuring the SliMP3 wasn't as simple as one button push, but it was close. The option that uses DHCP and automatically discovers SliMP3 servers worked perfectly for me.

The SliMP3 comes with a Sony generic remote, which you must first program (through five or six button presses) to be a SliMP3 remote. This felt out of place in an otherwise seamless install--the TV, tuner, TiVo, and DVD player I have in the entertainment center all came with remotes that worked out of the box. That said, the instructions in the booklet were easy to follow and in no time I was up and running.

Figure 3 -- the goodies in the box

The screen of the SliMP3 is one of the first things you notice--the crisp 40x2 fluorescent display is very bright and easy to read from a distance. Blind codgers like me will appreciate the option to supersize the text, making it very easy to read from across the living room. When powered off, the SliMP3 displays the time, which turned out to be surprisingly useful in our house. Thanks to NTP, which keeps my server's time accurate, we now have a very visible authoritative source of time around the house.

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What's really cool about the SliMP3, though, is that the server is optionally controllable through its own web server. From your browser you can change what's playing, pause, change the display, change the volume, and otherwise tweak the SliMP3. That may not sound like much, but if the living room is filled with three year olds who are clamoring for Queen's Greatest Hits, it's sheer pleasure to be able to queue "Another One Bites the Dust" from one's office rather than have to descend into a veritable hell-hole of toddler trouble. Not that this has necessarily happened to me.

Although the default configuration has games disabled, the server can offer games via your SliMP3. Tetris and a horizontal shooter are the two standard games, but other people have extended the Perl server to add their own features. Someone's even written a BBC news ticker. This opens itself up to all kinds of fun: subliminal messages, an interface to FestVox so it can read the headlines as well as display them, a biff-style mail alert, visual load averages for your machines (via ruptime?), fortunes, Choose Your Path adventure games, and much much more.

The Mac OS X SliMP3 server installed trivially, read my iTunes databases, and even noticed when I updated my iTunes database. Because the SliMP3 server can translate streaming mp3 formats like Shoutcast, Icecast, and Live365, I was able to drag the KCRW public radio simulcast to my Library and within a few seconds it was available on the SliMP3 player. I don't think anything has impressed me with the SliMP3 as much as this. Now if only my local NPR station offered an mp3 stream instead of RealAudio and Windows Media!

From the SliMP3's remote control you can browse and search saved playlists, albums, artists, and genres. This quickly taught me how appallingly tagged my 30 gigabytes of mp3s are--I like basic genre distinctions like "Jazz", "Rock", "Bluegrass", "Classical", and somehow I have mp3s that are tagged with genres like "Alt-Folk", "General Folk", "Folk-Rock", "Contemporary Folk", and many other variations on the same theme.

There's also some dubious classification--while The Proclaimers' "I Would Walk 500 Miles" is arguably Blues, Lenny Henry's "Live and Unleashed" album is far from "General Classical". Fortunately, the SliMP3 lets me browse the music folders as they're laid out on disk. Because I have a sensible directory structure, if not consistent tagging, I can quickly find what I'm looking for.

Tracks start playing as soon as you hit the play button on the remote control, and I've not once noticed a network lag. In fact, the SliMP3 is blazingly fast and puts the TiVo and on-screen cable guide to shame. It's possible to find the album or track you're looking for very quickly, once you have your head around the SliMP3 menu system.

The SliMP3 has features I haven't used in the week and a half that I've had it. For example, there's an alarm function that will make it play a specific track at a particular time. I haven't found a killer app for this (three year olds act as organic alarm clocks, although there are times when I wish their volume and playlist was as variable as the SliMP3's) but I'll keep trying.

The SliMP3 isn't perfect, though. The power button on the remote control repeats, so it's easy to turn your SliMP3 on only to turn it off again immediately. It's also easy to get lost in the maze of browse and search options, and it takes a lot of time to get used to when the remote's left arrow backs you out of a menu vs when it returns you back to the root menu (this is, however, configurable via the web server). These are minor UI glitches, though, and the overall convenience and functionality still leave the SliMP3 ahead.

Overall rating: 9/10. The SliMP3 is a perfect gift for the mp3-collecting geek in your life. Santa gives it two elves up!

Nat Torkington is conference planner for the Open Source Convention, OSCON Europe, and other O'Reilly conferences. He was project manager for Perl 6, is on the board of The Perl Foundation, and is a frequent speaker on open source topics. He cowrote the bestselling Perl Cookbook.

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