VTL tubes 6550A,B,C, WA or WB?

I'm using VTL MB250sig, what are the tubes that VTL using and the differences between those tubes...

Thanks

hi507-14-2009 4:02pm

hi5 OP Details Discussions Posts This discussion Message User 60 posts 07-15-2009 at 12:57pm Copy Comment URL Report Comment Edit Delete It seem that I hardly get an answer regarding VTL....