I like to play guitar thru the Helix LT (using Headphones) while jamming to music from my PC coming in via USB. I've noticed the volume of the music is full until I start playing guitar, then the incoming music is reduced greatly in volume. If I stop playing guitar, I hear the music slowly ramp up in volume to full level. I've tried several apps to play the music: MediaMonkey, Media Player, VLC, Quicktime. Is the Helix doing this? Any suggestions?