Bob, Ryan prefers Cardas Clear Light USB, and that's what I'm using from an ultra Rendu to QB-9 DSD in a secondary setup. I also use balanced Cardas Clear Light cables in my primary setup.
jafant, my DX-5 was already a DSD, bought sort of locally (seller Beverly Hills, we're in Montecito, aka Santa Barbara). I sent it to Ayre to have the chassis changed from black to silver to match the rest of my Ayre stuff.