my mate came round the other day and plugged in my amplifier and speakers to my pc so i could listen 2 songs on that (my current cd player is bust) however the sound coming out isn't pleasant as it used to be, its got a deeper bass and a lower trebble, no matter how high or low i change it on the amp itself, and i get this constant "bbbbbbbrrrrrrrrrrrrr" noise which i suspect are my fans? (i hear people get fan noises in headphones) how can i get rid of this stuff? how can i make the sound good?