Hi, recently I noticed that there is a noise in UX2 inputs but it's so quiet that I had never noticed it before I can't really hear it until I put a compressor or an effect on and turn up the gain, this happens when I have nothing plugged in when I plug in my guitar and the volume of the guitar is at the 0 the noise is gone but I can't really tell if it's there when I play cuz it's so quiet, I also own a POD HD500 and I can hear the same noise on it too my question is, is this something normal? Or is there a problem here?