Mcintosh MA5200 as a preamp


I’m trying to use my MA5200 as a preamp. I will be using a 320w per channel mc7106 (bridged mode) as my power amp. there are jumpers on the back of the MA5200 for pre out and power amp in. I tried hooking up the pre out to the power amp but no luck. Can anyone guide me?
andrewkelley
There was an issue with the gain sensitivity the guys at Mcintosh helped me out 
   Take  a look at the owner's manual. Maybe that will help