I am looking for a smoothest sounding outboard DAC

I'd have to say that the Dodson 217 MKII D (the latest iteration, recently discontinued) is the best bargain on the used market: retailed for $5995, can be had for around 3k. There's a very good reason this dac is used by many audio societies; I found the sweet AND detailed sound to my liking, as well. I owned the Bel Canto dac immediately before...no contest (of course, for the price difference, there shouldn't have been). It loved my CEC transport, BTW. I am curious why Dodson gets so little respect from 'gon-ners? Could it be that he is a self-marketer? A bonus: Ralph is great to deal with, patiently helping you get the most out of his design. Try getting THAT service with corporate gear!

In my experience the Zanden 5000 and Audio Note DAC 4.1x Sig., both with no brickwall digital filters, are the best sounding dacs by far. I would also include the DAC5 Special, but it adds little over the DAC 4 Sig.

I agree with the dodson 217 mk 2D. I owned one for a year and a half before changing for an audiomeca. It was a great dac and I am considering one for my second system. The sound stage was so wide and deep that I bought it after listening to only a couple of cuts. The audiomeca was slightly smother in the high end and a litte tighter in the base, but the difference is slight. Also, if you have the bucks, several folks are also raving about the new dodson (it's freeze dried!)... Call Ralph and he will sell you.

I'm happy to second the endorsement of the Chord DAC64. I haven't had opportunity to try lots of dacs, but the Chord, discovered entirely by accident through an issue of HiFi+, has made it possible for me to enjoy CDs for the first time.
To my old ears, it rivals SACD.
jp

I JUST GOT A CHORD DAC 64 AND IT BLOWS AWAY MY KORA HERMES and that is saying something.