pitch

Hi there, I found an old turntable in my grandpa's house and as I don't know a lot about it and don't understand most manuals I find on the internet, I need some help. It is a Dual 704 (imgur link below for pictures), I figured out that it doesn't have a build-in pre-amp (I got one, see the...

When I play Battlefield 3, my new headset http:// produces a constant low pitched whine that changes when I look at different surfaces. This sound is very annoying and I do not encounter it anywhere else. What should I do? edit: When I mute the headset, I still hear this sound?