Difference between Krell KAV-400xi and KAV-300IL

Bigger transformer (750 compared to 800) and has a volume control knob and the binding post is WBT now and they 400xi comes in black as well as an option.
Side by side listening test, its hard to say, thats how close they are.

Good luck

Howdy, I just picked up the KAV- 400ix to drive my B&W CDM9's. The "400" sounds great. I am very impressed with it so far. I didn't do a side-by-side with the "300", as the dealer didn't have both units on the shelf. I can tell you that I was the fourth person to buy the "400" this past Saturday at Spearitsound in Boston. They are "reasonably" priced for the performance. If 25 hundred dollars can be considered "reasonable".