Wow! Big difference with the Obbligato's which replaced some chiclet sized caps on the opposite side of the board. Very defined bass and the high notes just hang forever in space. Great airiness in the top hats on Sonny Rollin's Sax Colossus. I've still got four more op amps to upgrade and a ps cap but it's hard to imagine it getting better. To quote a guy on AK regarding these mods, "stunning, just stunning"