The SED 6550's have been out of production for a while now from what I've heard. That being said I have the SED 6550's and Genalex Gold Lion KT88's but in an Octave integrated. Personally I think the GL KT88 has better deeper bass with a slightly clearer mid range and the highs are about the same. I prefer the GL KT88's over the SED 6550's in my system
