Just redoing my board a little and when I was hooking up the power supply ( Voodoo Lab 3 Plus ) I rechecked the MA of the 6X and it said power either 9 or 12 VDC 220 ma. I have the option for 9 or 12 VDC. What is the difference of running one over the other? Is 12VDC optimal? I had been running it at 9 VDC.