Pre Amp recommendation

I want to move from 2 channel to HT but want to keep a separate amp and pre-amp for the mains. I plan to buy an AV receiver to cover the center and surrounds but need to pass it through an "HT bypass" or "unity gain" input on the preamp. Doew anyone have any recommendations for a solid state preamp with a good phone section for about $2000 used that has this feature.

Thanks