In this case the SE headphone outputs and the SE Pre Outs are not sensing either. Just got my amp in last night and am very pleased. My ears (or the amp) aren't fully burned in yet but I am surprised how different it sounds from my Gustard. More detailed, not as dark. Not bright or edgy (unless the recording is). Sounds great with a wide variety of phones.
In my setup the pre-out not cutting off is fine. What IS too bright is the front LED. I do not have other Schiit to compare it to, but far brighter than any other amp I have used and in a bedroom setup that's not good.
Fortunately there is a $7 Lightdims solution. Amazon's $111 install charge seems a bit high but my neighbor is a stamp collector so can provide technical advice