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