McCormack DNA-1 Rev A question

I was fortunate enough to have purchased a DNA-1 Dlx Rev A from a fellow Audiogoner. The amp that it replaced is a DNA-1 Deluxe. Yes, I am moving up the food chain, and boy does it taste good. The question I have is what is the purpose of having 2 sets of Cardas binding posts for right and left channel? I know this is a 2 channel amp. I just connected my speaker wires to the bottom set of posts. My original Deluxe only has 1 set of Cardas binding posts on the bottom and it looks like there are some screw type of binding post above that. I couldnt figure this out so I had to ask. Thanks for your responses