I would suggest the brand new Pass Labs XP-15. It has adjustable gain via dip swithes on the rear. I believe it has balanced outputs and it costs under $4K new. I have the older 2-box Pass XOno and it has balanced outs. It is very quiet and close to neutral. The XP-15 is supposed to be slightly better for less money. Though this sounds like a dealer's pitch, it is not. I'm just a big fan.
