Took apart the DAC I like and looked for the chip nomenclatures.

No wonder I kept telling myself the thing was special, either that or
my ears were growing aesthetics.

Tracked it to all over hifi forums and Ebay in kit form.

This one is minor, apart from knowing what the end of a soldering iron
means when going after the Cirrus Logic chip:
http://pavouk.org/hw/modulardac/en_cs8416spdif.html

CS8416 kits on ebay, a couple go similar, but most are totally nuts in
much higher relative build complexity. (And, as a courtesy, offer to
do the surface mounting.)

Messes with me. How in the hell can a little chip like that on a
TOSLINK light-carrier cable make sound so damn good.