Classe cp-800 add ssp 300?

Hello all. Quick question. Would I be able to add a ssp 300 to my 2 channel cp-800 simply for ht processing at a later date? I thought about the ssp-800 purchase but I got the cp for a steal so had to move on it. I am not sure by using xlr setup now (cp to my ca-d200 amp) if the signal would pass to a ssp-300 rca as the 300 has no xlr capability. 

Cp I would use pass through option  & volume control would be on a ssp 300 for movies... allowing my mains to function or would I be stuck having to use ssp 600 for the xlr out capability. 

Thsnks in advance.  I'm sure this has been addressed as did to a good search before I posted ;)