Marantz SC7S2 preamp question

I've a Marantz SC7s2 preamp that is connected to my power amp through the XLR connections. I want to connect a Dynaudio 500 sub that has one input.The preamp has 2 unbalanced outputs. I'm wondering if I can go from 1 pair of the outputs to the single input on the sub, creating a y cable. Will this cause any problems that anyone is aware of ?
Thanks for your help