LH Labs geek out 1000 High Performance USB DAC and Amplifier. I've used this up until very recently as one of two primary DACs in my (old) living room system, running Audirvana Plus straight in to my preamp. Replaced it only because of W.A.F. issues and her need to simplify both the operation of the system and the aesthetics (now using a well-known and rather expensive British all-in-one). The geek out 1000 definitely sounds better than the DAC in our new system, and it also does DSD. The other DAC used in our old system is a well-known Eastern European tube-based unit, now also for sale.
This DAC is in great condition, works perfectly, and really does sound great. I never tried it with headphones so can't comment on how that may sound. I've misplaced the little information sheet that came with it, but I believe a PDF is available online.
I prefer payment via PayPal. I'll pay the fees and shipping to the lower 48. Contact me for other shipping locations.
Don't hesitate to ask if you have any questions or need more info. Thanks for taking a look!