Man my head hurts. 
Ok so maybe I’"m confusing myself and everybody else. I’m really sorry about this…
On the Babyface there is NO line level input; just it’s XLR connect on the breakout cable (think Apogee Duet). If I don’t hit the 48v or Instrument it’s Line Level. On my ADAT, there is both an XLR (dubbed MIC IN) and Line In.
Basically my question is that if I use gain on the Line Ins am I in effect using the preamp? Should I stop using gain on Line Ins as gain is used for instrument or mics? The idea being I boost things in the mix…