I have the same problem. I was listening to my monitors and it was in stereo. I plugged in my headphones in the back of my Audiobox USB96, and the were Mono. Never had this problem ever. The suggestion was to use a "Y" cable, but why? Studio One is not running and I have not used it for a week. I just updated S.O. 5 to 5.2. Would this cause the problem? I really wanted to check out my new BD 770 Pro, and now I can't. Plugging it straight into the laptop does not provide the impedance I want.