Used Metrum Acoustics Hex NOS DAC. Cosmetically, the DAC looks very good, with but a few scuffs on the top case. The DAC has been upgraded by replacement of four 3.3V regulators with Paul Hynes shunt varieties, which upgrades the already excellent sonics of this unit considerably. A full upgrade would replace the 10 5V regs, and the Lundahl output transformers, which would bring this DAC into TotalDAC territory, but not an upgraded TotalDAC (see the pic). Suffice it to say the Hex outperforms anything non-NOS I've heard, and I've heard a lot. It creates beautiful music.
This model comes with a USB input, and has two coax and two optical inputs. Price is very fair, and firm.