I don't want my home theater components to be in the chain when listening to two-channel music. The home theater gear is on a completely different level (lower). I use a nice Onkyo receiver for surround processing, but I doubt running the front channels through my LTA MicroZotl preamp is going to degrade the sound quality.
My previous conrad-johnson preamp had a true pass through. The LTA really just fixes the volume on the input that is designated as Home Theater. I set the channel levels with the Onkyo. Works well enough for me.