After several years of buying/trying/selling various tube and SS DACs including the Nixon TubeDAC, Monica, MHDT labs Paridisea, ack DAC, etc., I finally settled on the amazing Promitheus DAC...After spending about a year with it, I replaced the opamps with discrete opamps from Burson audio ($200) and put a Felix AC filter (~$30) on the incoming power supply to clean up the incoming power...Its worked flawlessly since I bought it and has always made wonderful music...I'd characterize the sound as involving with good PRAT and an organic feel to the music...imo, it's the best non-OS DAC I tried, actually probably the best DAC I've tried...But system and family changes are requiring me to downscale...my loss is your gain

For more information about this DAC check here:
http://www.promitheusaudio.com/dac.htmIt has two digital inputs (BNC and coaxial, not USB like the latest version) and a single set of RCA analog outputs...Also, standard IEC power connector...
I have about $800 into this unit currently and would like to get $500 plus shipping...If paying via Paypal, I'll split the fees...
Thanks for looking and if you have any questions, let me know....