I have a Wavelength Proton that sounds pretty with my system, however I can't help but think there could be advantages to upgrading. Among options I have considered are Bel Canto, Wyred 4 Sound, and Ayre with the hope of targeting $1500 to $2000, new or used. My question is, would the upgrade be worthwhile or would money be better spent elsewhere, and what is your favorite in that price range. Thanks for the input.