You might want to talk to John Chapman at Bent Audio..http://www.bentaudio.com/index2.html, He can build you a passive NOH balanced preamp that will take your system to a higher level. I used one with my Ksa-250, the only problem you MAY or MAY NOT have is the somewhat low sensitivity of your speakers. I also have Acoustic Zen speaker cables and my interconnects between my Sony XA777 and the Bent passive were Harmonic Tech. T-links. I am going to order another Bent in a couple of months as I had to sell mine not long ago.
Dave
Dave