I am having trouble deciding what i want to do. I have a yamaha rx663 7.2 avr. I am trying to decide if i want to buy a new one either a Denon 3312, or a Marantz? Or do I want to keep my Yammy and add a amp like a Emotiva,Rotel,Parasound,Integ,etc... I have never really experienced an amp before but i know thats the way to go . MY speakers are RTI line from polk audio.