i recently added an Anthem MCA-3 power amp to go along with my denon 3801, and i've since noticed a slight increase in hiss from my speakers. The hiss is not audible from more than a foot or so away from the speaker, but it is definitely a bit louder than when i was using the denon's amplifiers. At first i thought it was the anthem amp which was adding the additional hiss, but if i leave the amp powered on with the 3801 off, the speakers are almost dead silent. I have to put my ear directly to the tweeter and even only then can i BARELY hear any noise. However once the 3801 powers up the hiss returns. I realize that there will always be some amount of noise but im just curious as to why the hiss has increased from before adding the amp. Is it simply that using the preouts on the 3801 adds more noise than the "internal" wiring?