Interesting thread and how misquoted I was. All along I told guidocorona that only the 6L6GC tube would be replaced by the 6550C. I was somewhat surprised because I am not a big fan of the 6550C--however once the tube was swapped and the bypass caps added there was a distinctly deeper bass as well as a much smoother upper end.
What to me is the $64 question is what the unit would sound like by swapping the 6550C for a KT88?
Here is a look at my system with the Ref3
http://forum.audiogon.com/cgi-bin/fr.pl?vaslt&1049587927&read&3&4&
http://homepage.mac.com/imacdoyou86/PhotoAlbum52.html
What to me is the $64 question is what the unit would sound like by swapping the 6550C for a KT88?
Here is a look at my system with the Ref3
http://forum.audiogon.com/cgi-bin/fr.pl?vaslt&1049587927&read&3&4&
http://homepage.mac.com/imacdoyou86/PhotoAlbum52.html