Im using the Yamaha DSPAX620 and Mission M series speakers. When using the dvd digital connection even with the dvd sound off i can turn the amp up as loud as possible and it is still quiet. If i choose any of the other inputs ie for watching sky etc, i get a hissing sound. Whilst watching sky the hissing is really starting to annoy me. I thought it was the phono cable between the skybox and the player so i changed these but it didnt change so i then removed this cable altogether and turned the volume up without anything plugged in and the hiss is still there. Does everyone else have this?