Preamp to Run Revel F52s & C52s

Hi everyone. I posted this ? in the Home theater section also. Sound improvement in 2 channel is a major factor in my thoughts of upgrading and I would like as much input as I can get. I currently power my Revels with an Emotiva xpa-5 and use my Onkyo TX-NR801 as my pre-pro. I want whatever I buy to serve double duty as a home theater and 2 channel music unit. Anybody have any suggestions what would serve my Revels well?
I have the F32's and C32 and run mine with a McIntosh MX135 in theatre mode and when I am listening to 2 channel I am using an Audio Research LS26. I get a very good detailed sound out of both. I did gain a good step forward by adding the seperate 2 channel preamp and using it's unity gain for pass thru on surround. You may want to keep the Onkyo in place and just buy a 2 channel pre amp with unity gain. Some manufactures call it cinema pass thru, theater pass thru,processsor pass thru, etc. You will gain a much better step forward by adding the processor pass thru. It basically allows you to have 2 systems in one. You didn't mention a budget?
something anyone should experience is the axiom piece for a simple 2 channel that will blow you away! Great music doesnt have to break the bank Good Luck
Thanks Theo, I have to admit complete ignorance to the ever changing electronics world. How does the theater by-passs work? Wiring etc.... Would like to keep budget around $1500
Theater pass thru is a circuit the takes the 2 front channels out of the pre-pro and directs them to the amp.This allows you to have a stereo pre amp and have your 2 channel sources utilize a 2 channel sytem. In my case I have a 2 channel amp so 5 can turn off the other multi channle amp and pre-pro. This leaves me with a 2 channel system for cd, tuner,vinyl etc. All I do is select "proc" and the unity gain allows the pre-pro to drive the volume for all channels including the two fronts. Flip it to CD and the 2 channel pre amp runs the volume. At 1500 you can look here on AG and find some real good buys.