Recently I received my THX 789 along with the Drop x Grace balanced dac. With headphones plugged into the amp there is ZERO audio until the nob is in about the last 5% turned all the way up where it is extremely distorted and unrecognizable. When plugging the headphones into the back of the dac there is audio that sounds just fine. Why would it not work when plugged into the amp? I've tried swapping cables, uninstalling drivers, turning off audio enhancements, updating windows, and just about everything else I could think of. I also tried taking the amp and dac and plugging them into a laptop and there were zero issues when plugged into the amp and audio levels were perfect. Any ideas what the issue could be? Any advice or ideas would be greatly appreciated.