Project86 has posted a review of the Audinst HUD-DX1 DAC/Amp on Head-Fi.  Price point is just under $400.


Pros: Bold, lively sound from the DAC portion, headphone amp powerful enough for planars, rock-solid stability over USB
Cons: Gain is too high for some headphones and especially IEMs, price isn’t as low as I’d like

Review of the HUD-DX1