I am using a Mackie Pro FX 16 mixer connected to my custom PC by usb. My Mbox is used as my interface and the stereo outs go back to my Mackie. And then out to my stereos aux inputs. I have an MPC 2500, a Casio WK3800, a Roland Juno-G, an American Audio turntable, and an Alesis Micron I use as a...