Kaliko Systems Limited

Make a Low-Power Media Server

History and Lessons Learnt

Several years ago I decided that I would design a PC based music jukebox to sit with my Hi-Fi. This would solve the twin problems of listening to my growing amount of hard drive based music and finding music in my rather unmanageable CD collection. The opportunity to build the jukebox came when I had components left over from upgrading a games PC. So I purchased a low-profile PC case (1U high) that looked good with the Hi-Fi and "stuffed" the now spare Athlon1700+ motherboard into it. I tried using the on-board sound for analogue output into my Hi-Fi, but it did not sound good, so I replaced it with a much better sounding SoundBlaster Live card. I used Fedora Linux to allow scripting of features like, random play, favorite lists, etc, and used synthesised voice announcements for introducing the next track. I use this set up for a year and learnt much from it:
  1. Heat. Standard PC processors get hot quickly in a small case, even with copper heatsinks and fast fans. Hot components worry me, as they are more likely to fail.
  2. Cost. Standard PC parts are cheap to buy, but they are power-hungry and therefore expensive in the long-term.
  3. Noise. Even a quiet fan is noisy while playing music; you really need fan-less operation for a system in the same room as the Hi-Fi.
  4. Compatibility. A standard PC soundcard's output voltage is about 10-20% of that from a Hi-Fi CD player. This results in having the amplifier's volume control high, causing very loud music if not careful when changing the input source on your amplifier.
  5. Size. Small PC cases are rather inflexible when wanting to add extra disks or cards. For instance, when I wanted to add a remote control card I had already used up the only PCI slot in the case with the sound card.
  6. Interference. A PC near the Hi-Fi's tuner is not a good idea, as the PC creates a lot of radio interference.
  7. Interface. Synthesized voice announcements to introduce music sound robotic and are difficult to understand.
  8. Spin-down. USB2 external disk enclosures are very flexible, but normally they don't support disk spin-down. Without spin-down multiple external disks use a lot of electricity and have a shorter life.
At about this time, Slim Devices introduced their Squeezebox 3 network music player, and although a little expensive, this features: exceptional sound quality, no fan, a display viewable across the room and a good looking remote. I purchased one, and was so pleased with it I purchased another. A Squeezebox uses music tag information (standardised data embedded in music files) for its menu system, but my music files are from many sources and so not all the files have tags, and even those that have them are often not tagged in a consistent way. It took a lot of time to both add tags and to get the existing tags consistent, but without consistency it makes the Squeezeboxes much harder to use (the capabilites of the free Mp3tag program were good for my MP3 and Flac music files). The Squeezeboxes need a music server, so I purchased a Linksys NSLU2 NAS device (a.k.a. the Slug) to use as the music server (and also as a general-purpose file server). The Slug is exceptionally low-power (about 3 watts) and can be modified into a general-purpose micro-Linux server. However, the memory in the Slug is limited, so it is slow with large programs. As a Squeezebox Server it was fine for streaming music files, but painfully slow when using the Web interface and creating the music database. I also wanted to use the Slug as a low power 24x7 family bit-torrent machine, but the standard Slug bit-torrent application is Linux command-line based and can only download a single file at a time; my family is used to Windows XP and so found it too difficult to use.

When Intel introduced their Atom boards, I saw an ideal update to my previous PC jukebox, to make it into a general-purpose media server. Not only to replace the Slug as a music server, but to also provide video serving and a family-friendly bit-torrent machine. I considered purchasing a new case, but decided against it, as I use extenal disk drives and only need a single PCI slot (for a TV card). I have now had the Atom for about a year and it has been reliable and easy to use.

Making the media server.
Copyright (c)2009 Kaliko Systems Limited