I just picked up a Decco over the weekend. It was a total impulse buy at a local store. I had seen some good things online, and I figured I could use it in my office if it didn't work out at home.
Anyway, I'm really smitten. I've used it with Klipsch Fortes (very sensitive at about 99db) and Totem Arros (87db). It really rocks the Fortes, and it is pretty polite on the Arros.
I'm feeding it with a Cambridge 640A CD player, and I have tried both analog, coax and optical. Connecting Analog with audioquest turquoise and coax with Kimber Digital coax.
I prefer the DA converter in the Cambridge. It is a bit more airy and it really makes a difference with brushes on cymbals. The DA converter in the Decco is OK though, and without doing a bunch of A/B listening for about two hours on various source material, I wouldn't have minded the internal Decco DAC. And it isn't like a couldn't live with the internal DAC, just that I prefer the one in the Cambridge.
The USB DAC sounds very close to identical to the Coax DAC as far as I can tell. I'm using a windows laptop with ASIO drivers. I did some A/B testing from identical CD's, one in the Cambridge through the coax input and also through the USB port. (By the way, the DAC locks to the signal very fast, so there is barely any gap between the two sources.)
Finally, I also used it with my Aragon 4004, and I think I found its real niche. I wouldn't mind using it as a DAC/Pre, mating it with a nice amp. I am really impressed with what's possible for $800, and I'm thinking of it as buying a Pre/DAC and getting a little 50 watt amp for free.
