I want to improve the sound of the 2 channel stereo of my HT system but am not sure what the biggest bang for the buck will be. Here is what I have now: Yamaha 2200 HT receiver. Advertised at 100 x 6. Paradigm Studio 100 speakers. (90db) 19 x 15 room with catherdral ceilings. Options up to $1200. 1 - Add an external amp such as Rotel, Parasound, Oddessy. 2 - Upgrade to a higher end receiver. 3 - Others ??? I have some concerns though. Will adding an external amp really improve the sound? Will using the Yamaha as a preamp defeat the purpose? Anyone have experiance/pain of this sort? Thanks.