Still searching for a Headless Raspberry Pi case for your Pi with Display / Volumio-Pi / MPD-driven mediaplayer? Here it is:

The HiFi-Pi!

The HiFi-Pi-Case is a Case which snaps together, is suitable for wall-mounting, has it's I/O on the bottom, and only has the important plugs on the outside: Power and audio. It's designed to run headless, without LAN, HDMI and so on.

Things you Need:

• a PI (model B; B+ should also work but untested)
  
• an USB-DAC (i used this one: http://www.amazon.de/gp/product/B00BBCXVG6/ref=oh_details_o00_s00_i00?ie=UTF8&psc=1 , and removed the casing)
  
• a display (STLs made for a hd44780-20x4, but a 20x2/16x2 will also work is you modify the corresponding part in the scad)
  
• a small usb-wifi-adapter(e.g. the cheap edimax ones)
  
• a dc-hollow-jack, 2.1mm (or with whatever you want to power-provide your PI with)
  
• an audio-distro for your PI like volumio (or self-configured; whatever...)
  
• M3x6 screws and washers, nuts..
  
• Short, old USB-Cables or parts of them for inner USB-cable routing
  

The case can be modified through the scad-file; however, its not fully parametric, but i added it anyway for smaller adjustments like changing the display size.

i made the little tray an extra part, so that you don't have to hassle with several hours of reprinting, when your soundcard or your powerjack might not fit. also this small part can easily be redesigned to fit your hardware.

Feel free to remix, and please let me know if you managed to make one of this cases, i will soon add a version of the top-part for buttons.

Be careful when snapping the two parts together, depending on your layer-lamination the snap-clips might break apart!

The Power jack should be glued in. it just provides the best connection. I actually zip-tied the sound-card to the tray, but i think finally i will hot-glue it, to avoid pushing the soundcard in when plugging the jacks.

to keep the display free from active parts, you can add a ~150ohm(depends on your display) resistor to the contrast, for me it has the right contrast for readability. (hd44780: resistor between P15 and VCC)

I stripped some cables of, it just fits better. In a closed case its unneccessary to use bulky plugs everywhere, so i directly soldered the power-in-usb-jack to a dc-jack; to one of the usb-ports i soldered an USB-cable to be able to re-route the USB-DAC to the tray.

printed in black PLA, ~50mm/s speed, 20% infill, 0.35mm nozzle and 0.25mm layers