Box is a QNAP TS-109 running Debian GNU/Linux. It plays music using mpd, and provides me with lots of handy USB ports. I embedded the board inside a working stereo. (Slug is an earlier prototype of this project.)

The computer's front LEDs are visible through what was originally the CD bay. Below it, two USB ports are embedded in what used to be the CD eject button.

The cassette tape deck no longer reads tapes. It has a 4 port hub in it, and can be closed with small USB keys inserted. Hit Stop/Eject to change USB keys. :-)

The Build

Building this took three evenings work. First I found a stereo that seemed the right size. Of course this involved guesswork, and in the end, I just got lucky. At times I had tolerances of a millimeter! (And, at times, I got creative on the plastic with a drill, knife, etc.)

The stereo was disassembled, and only the electonics needed to drive the radio and control panel retained.

The black box in the above picture is a small USB sound card. This was soldered to the audio input (AUX) leads of the stereo's audio IO board.

This stereo had a large battery bay (some 9 batteries of 3 sizes!). I ripped that out, giving access to the inside of the case from the battery door.

The plastic mounting rails seen above hold up the radio board, and were later modified so that the qnap board could rest between them.

I found a tiny 4 port USB hub. Luckily it fit perfectly inside the big "eject" button of the CD drive. This hub is illuminated, and has two forward facing ports that are accessible from outside, and two rear ports, allowing connections inside.

First the USB sound card was mounted on top of the audio IO board.

Then the tiny hub was mounted in place above it.

I also mounted the QNAP's serial daughter board, accessible via the battery bay door.

The QNAP board mounted in the case. There was just enough free space on the right to stuff in its power brick. Luckily, this power brick runs cool! (There is some venilation.)

The radio board fits over the QNAP with centimeters to spare.

I found a tiny USB keyboard, that measures 6x4 inches. This is velcroed to the top of the tape drive door, or can be removed to place it in front of the radio. I added a mprompt command to mpdtoys that makes it easy to control mpd using this keyboard. Just walk up, type in the name of an album, artist, or song, and it will start playing. Arrow keys control volume and skip from track to track.


  • At some point I hope to add a translucent plate over the exposed front of the QNAP.

  • The radio tuner was unfortunatly right above where I put the QNAP's power brick. When on, the brick generates so much interference that the radio can't be used. I may try to add shielding or relocate the brick. However, I don't anticipate using the real radio often.. This box can use internet radio instead.

  • If I could find a cheap, small USB LCD display, I've love to shoehorn that in.


Total cost for this remote controllable stereo, running entirely open software, that contains my entire music library:

  • $0 TS-109 (already owned it)
  • $20 stereo
  • $5 usb sound dongle
  • $25 mini usb 4 port hub
  • $25 small usb 4 port hub
  • $25 tiny usb keyboard
  • $5 glue, putty, and other misc materials
  • $120 total