I have a Marantz AV600 that I used for 2 channel music. I decided that I wanted to start building a home theater and purchased a center channel speaker. Well looking on the back of the Pre-amp revealed both a left and right center channel pre-out. Does one of these turn into a mono if the other isn't used? I don't have a the manual so I am confused.

Any suggestions will be appreciated.

Also, if somebody has a manual that they can copy and mail to me, I will gladly pay a couple bucks for your time and effort!