extending AV to 2 channel
I am new at this so please bear with me. I am by no means an audiophile but I certainly enjoy music and video and want to make the most of it. I own a pretty decent Denon Av receiver, I believe its a model 1803. this component allows for output to a second amplifier for use in other parts of my home. I also own an old Yamaha "Natural Sound" integrated AMP and Tuner from my college days that frankly sounds great and packs a lot of punch. I'd like to extend the system so that I can have 2 additional speakers in the dining room and back deck. My question is, can I connect an older 2/4 channel stereo Integrated amp to a much newer surround sound receiver and still get quality results? How would the connections be accomplished?