I'm goinG tO TaKe a guess that tHE " sound loop " you're talking about is an oscillation. If this is it, you are getting an annoying and rather powerful squeal coming from your speakers(or head set). It sounds like feedback only it is constANt and happens instantly. The cAUSE OF THIS<(again just guessing), is likely that your output from the soundcard is going into a channel on the board which is then going out of the board into the input of the soundcard. This is the "loop" you have created. If you have the master left/right outputs going into the soundcard you need to fix this buy changing your setup a bit. I suggest that you change the soundcard input from the master left right, to either an aux output, or the output from a subgroup if your mixer has this. You would then assign your playback to the left/right output to headset and/or speakers, and your record track to aux or subgroup. This way you can eliminate the loop, while controlling what you hear and when you hear it completely.