adding surround backs, quick question

Folks, I'm experimenting today with adding two surround backs to my system.  I have the speakers, cable and and a spare receiver to make this happen just temporarily to see how it sounds.  My system is a Marantz AV7703 processor, Rotel RMB-1555 five channel amp and a few sources for CD, DVD, SACD, etc.  I also have a spare Marantz SR6006 I store away as a back up to my 7703 in case something happens to it.  I'd like to use just the amplifier portion of the SR 6006 to drive the two surround backs.  I plan on plugging in the surround back outputs of the 7703 into the Aux2 input on the 6006.  But which speaker jacks do I use to drive the two surround backs?  I play all formats including multi-channel stereo.  I noticed the SR6006 has a set of speaker output connections called Class 2 Wiring.  Is that the circuit I should activate?  How do I set this up?  THANKS.