First off, this forum is terrific. Lot's of cool information on here that's certainly helped in my headphone and amp-buying experience.
My question is with respect to the variations in line-level designations and its relationship to consumer headphone amps. Specifically, would a professional line-level signal pose any danger to a "consumer" headphone amp? I know that there's a ~12 dB difference between professional and consumer line level signals, so I just wanted to see if I can run a direct feed into an amp or if I should rely on a "step down" box of sorts like the ART CLEANBoxPro (http://www.sweetwater.com/store/detail/CleanBoxPro) to bring the signal down to consumer line level.
I was hoping to incorporate a set of HiFiMan HE-400's into my music production setup, hence my asking.