- is the signal out from your cable/dvd at max volume? Trying to amplify a very weak signal will introduce noise
Otherwise, it's likely something hooked up to the receiver introducing noise. Try unplugging everything, and then listening to every individual input.
You may be able to isolate which component is introducing the noise. Personally my receiver has "source-direct" and "pure direct" modes which are way worth it and give a silent noise floor unless your ear is right up to the receiver... see if the H/K has anything that works in a similar fashion.
ON that note, does anyone know a brand of prepro and a brand of amps with a VERY low SNR? Who doesn't want to be able to have no signal and turn the gain and volume up to MAX and hear pure silence.