Computer Audiophiles: read the Stereophile review in December 2011, where John Atkinson calls this USB interface current "best sound quality I have heard from an outboard USB converter".
Included in this sale:
Empirical Audio Off-Ramp 4 (MSRP $1299)
Dual Turboclock upgrade (MSRP $700)
RCA input jack instead of BNC (MSRP $25)
A DIY Battery Power Supply Kit (if you buy the Empirical Monolith it is $1199)
Everything is a few months old and in like-new condition.
About the DIY battery power supply kit: It's simple but effective, a major upgrade from the switching AC power supply that comes with the Off-ramp 4. The stock Off-ramp 4 is already an upgrade to my Benchmark DAC-1 USB's own USB input, the upgrades, especially the Battery, makes all other USB interfaces sound unacceptable. Yes I have tried many from Halide Bridge to Stello U3 to M2Tech, the Off-ramp 4 is the obvious best, it gives the bass like Wadia 781, the midrange like Accuphase DP-700, and treble like CEC belt-driven transport. With my DIY kit you can use regular batteries from home depot (as shown in picture) or you can buy a rechargeable 12 volt battery for $36 off Amazon.
Read my feedback and buy from a long-standing audiogoner who knows what he is doing.