I just purchased the AudioBox USB 96 and set it up. Everything seems to be working fine except for the headphones. The headphone volume knob runs from 0 to 11. The loudest volume I can get out of the headphones is when I have it set at it's midway point (presumably at 5.5). If I turn the headphone volume up any more past mid-way, the headphone volume actually decreases as if I'm turning the volume back down toward 0. Is this something I can remedy on my end or do I need to send this back and get another. I'm using a pair of Sony MDR-V150 headphones--they have an 1/8" jack and I am using an 1/8" to 1/4" adapter.