I acquired this DAC (it is not the DSD version) after having a variety of <$1000 DACs in my system, including a Channel Island Audio VDA-2 with its external power supply; a Benchmark USB1 USB; a Schiit Gungnir; and a Denafrips Ares, none of which were distinguishable from the other in performance. However, the QB-9 was tremendously analogue-like in its performance in my system. As a matter of fact, I ended up selling my vacuum SOTA Sapphire TT shortly after I got the QB-9.
The QB-9 is limited to a USB input so I recently bought an Ayre Codex, which permits also a coax input so I can stream music from my CD player through it. The Codex is an improvement, but at 3X the cost of my QB-9.
My advice is that sub-$1K DACs are for the most part nondescript and I can say that the upgrade from most any of them to the QB-9 will astonish you, as it did me.
Asking $750. Paypal and shipping costs will be the responsibility of the buyer. It will be shipped in the factory packaging.