Just curious, what was your reasoning for using the KSA on the low end, and the KAV for the mid's and high's? I would have thought that the Class A operation of the KSA would really be sweet in the midrange. Also, how do the Apogee's sound run full range by the KSA, compared to your current passive bi-amp?
On a side note, I still have an old pair of Carver Amazing Loudspeakers that I replaced with ML Electrostats a couple years ago. I can't seem to bring myself to sell them, with the idea that I might someday put them into use again. I didn't have my Krell amp when I was running the Carvers, and I keep thinking about dragging them out and at least checking out how they sound under the control of a more robust amplifier.
Mike