If you are looking for a super transparent, purely passive transformer-based stage, give John Chapman at Bent Audio a jingle. He can set you up with any number of input/output combos RCA or XLR. You can get them kit or pre-built and they are EXCELLENT. No vested interest, here. I just owned one and thought it was great.
http://www.bentaudio.com
http://www.bentaudio.com