Since you like Krell, try the KCT. Rowland also sounds good with Krell (but different). A Hovland 100, Aesthetix or a CAT Ultimate may do the trick if you're into fast, dynamic & clear tubes. Ayre, Klyne and the bigger Sims should also pair well (I'm not sure about the impedance matching there).
Don't know the A-Illusions.
Pray, what's the budget & what are you looking for in terms of "sound" -- a clue or two :)?
Don't know the A-Illusions.
Pray, what's the budget & what are you looking for in terms of "sound" -- a clue or two :)?