I have an Elite VSX-37TX. IN order to take advantage of the 7.1 feature, I need to use a second amp for the back surround. I want to try this out using the old Elite as the second amp. I need some guidance on the wiring. The manual only indicates where to go out from the 37TX. What do I input to on the 2nd amp? Which speaker terminals do I connect to on the second amp? Any suggestions? thanks!