I haven't heard the 803s, but from everything I've read, it seems they perform best with high power. My KT88 Cayin amp was modeled after the MC275 and has similar power. I don't think I'd want to pair it with B&W 803s, but if you already own the 275, won't hurt to try it.
It's best if you can manage to audition gear somewhere, especially speakers, as they will have the greatest influence on your system's performance. You might discover you don't like B&W.
It's best if you can manage to audition gear somewhere, especially speakers, as they will have the greatest influence on your system's performance. You might discover you don't like B&W.