i got a mesa 400 and im kind of confused about the connections on the back. it has 2 out jacks labeled 4 ohm output, and 2 labeled 8 ohm output. if i am running it with 2 8 ohm cabinets, which set of jacks do i use? the 8 ohm ones, assuming thats 8 ohms each, or the 4 ohm ones, assuming its 4 ohms combined load? can any mesa 400 or 400+ users help me out?