If you don't mind my opinion I would look at a different amp all together for the B&W's. I am a B&W dealer and Krell is not a good match. It will sound super detailed but very harsh and make your ears hurt after an hour. The following amps will make the Krells sound like Technics on your speakers. Essence, Gryphon, Symphonic Line, Ayre, Classe, NRG, Coda, White, Pilinius, Arcam, or Halo. Just don't do tubes as the woofers on the B&W's love solid state.
Krell KAV-400xi vs KAV-2250+280p
Has anyone heard much of a difference between the 400xi and the 2250+280p combo.? The difference in price is around $4K, is it worth it? I'm looking to power a pair of B&W 803Diamonds. Would I be better off buying the 400xi for now and saving-up to purchase the 300cx+KCT later?