Skyflyer, I feel for you. You're lost in the Bo-zone. It's an part of the sky were high quality power amps only perform at their best with specific high cost cords.
I still think you're on the wrong track with the power amps. I hinted at it earlier and others, including Bo, have pointed out the XP10 may not be a great choice. You would get far greater sonic payback with improvements to your front end components.