okay, so I've hooked up my turntables to my computer. but I can't get any sound to come through my computer. I've got Sound Forge, and even tried the sound recorder, but recording isnt an option because there isnt even any sound coming from the computer. mp3's and all that work, but I can not get anything from the line in to work. I adjusted the volume control section for both playback and recording, and yet I can't get a signal. anyone know where the problem may be?