That thee back of my head. Correct me if I'm wrong I go from the Direct Out of my head using an XLR to 1/4 TRS balanced cable into my Radial JDI's input? How should I set the direct output level? Post or pre? Ground lift or ground? One more question. I am using this Big Block 750 with a Mesa Powerhouse 4x10 cab (8 ohm). How do I connect an additional 8 ohm Mesa cab?