I am a former power amp/passive speaker junkie. Having climbed the slippery staircase of Naim power amps from 140 - 250 - 135s, and oh what fun it all was, but this behaviour came to an abrupt end when I got my first pair of ATC actives. My Naim dealer was not happy when he found out what I'd done, because I was removed from the pool of people hoping to get a NAP 500.A few people have spoken about owners of passive speakers box swapping. But I wonder how much more power amp swapping goes on over those that own actives. I can’t think a single reason why I would change my power amp but I could be persuaded to change my preamp if an SP20 came up at the right price and that’s mostly because the SP20 has a headphone socket and my SP17 doesn’t.