I've built my system over 4 decades now - I still have the first album I bought - well actually most of the albums I bought (unfortunately some were stolen in college).
My system is the best sounding it's ever been and I'm enjoying music more than ever. Of course these are my personal opinion and what I think are improvements may simply be different. I've appreciated listening to different systems and their characteristics - especially over the last few years - and understanding the sonic aspects I find pleasant.
