Technically Wayne and Yogi are correct, but my ears told me different when I added my NAD amplifiers 218THX & S250 for my Klipsch 7.1 setup. Granted my Legend series towers are a bit bass oriented and still efficient, my Onkyo 105 w/ch receiver did not have the clarity, soundstage, crisp highs and clean power that these power amplifiers have. There is just a fullness to power amplifiers that a receiver can't produce. Juan, I suggest you mosey on over to the Klipsch website and search through their forums for more on this.
