In the late 1990s I had a 502, 508, 557 x 2 with Proac Response 2.5 speakers. It was a sublime system and still sounds fantastic to this day. I’ve moved onto DSP speakers for my main system now but have never been able to bring myself to sell the old system although I did give one of the 557s to my brother.

I can recommend adding a second 557 and bi-amping. I originally ran them in bridged mode assuming that the extra power was important. I’ll never forget the evening I spent bodging some Y-shaped interconnects to allow bi-amping and being completely blown away by the sudden improvement in sound quality. My Father was with me at the time and he couldn’t believe the difference either, eureka moments like that have been rare in my hifi journey.

Oh, and I used to leave mine switched on 24/7 unless away on holiday etc. I'm sure I read somewhere at the time that they were designed to be left on.