Towards the end of my last day of work for the year, I stopped by a local hi-fi store to see if they had anything interesting.
One of the guys pulled out a copy of the local Stereo magazine, the January 2013 issue, which was considerably thicker than usual, as not only was it a magazine, but included was a box inside of which was a small Luxman DIY DAC and headphone amp! The DAC is nothing special, just a BB PCM2704. The headphone amp looks a little interesting and rather familiar.* Unexpected was the Luxman-branded USB cable.
A year ago, apparently, they included a small tripath-type speaker amp of the same size in the box. Both amps match a commonly available DIY case available here. I plan to grab one, drill it out and stick it in there for fun. The magazine also goes into the design for a few pages, including possible mods, such as cap upgrades, S/PDIF or Toslink output and other things. For about ~$35 for the issue, I thought it was pretty cool.
*By "familiar" I mean it is using the same output opamps as the O2 amp.