OK electronics wizards and gear heads: I play gigs with a guy that regularly uses condenser mikes which require him to run the Phantom Power on his board. It is not individual to the channels. They're either all on or off. I give him signal off my rig through the XLR out on the back of the head. Problem is, my amp hates the Phantom Power and starts to distort (more in the signal to the board than my cab). This is the second amp I've owned that does this. I cannot use a regular direct box as I need the "effected" signal (from my effects loop) to get to the board. The question: Is there a box or adapter that I can put in between my head and the (Phantom Powered) board that will keep the voltage away from my amp?