I have a annoying low hum (sounds like static) when I plug my headphones in to listen to music. I can mostly here it at the lower volumes/quite parts in songs and was wondering what could cause this problem and how to fix it. The volume is not all the way up in any "option" and I do not get the hum when I have speakers pluged in. Also what would be a decent speaker set up for ~100. Thanks for any help.