Hi guys. I just got Rotel RA-10. It's good and cheap amplifier so I though it would be a great way to start with hi-fi. However I've noticed interference when I switch to inputs which are not active (nothing plays trough them). When I increase the volume it picks up some music playing from the other input. Is that 'normal', should I worry? Should I ask for replacement? Here's the video. https://www.youtube.com/watch?v=GqLY_PcN4rg