There's a bit here on biasing and stuff, it's aimed at owners of Fender Hot Rods, but it should give you an idea

http://studentweb.eku.edu/justin_holton/bias.html

ok but do the power tubes need to be "matched"?

clay wrote: ok but do the power tubes need to be "matched"?

Matching is a good idea, but manufacturer claims of "matched " sets are sometimes inconsistent. Groove Tubes has a "hardness" rating, scaled from 1-10, with "10" being the hardest tube. I use 10's in my Twin, because I want maximum headroom and loudness without distortion in my power section( the preamp section is another story). I don't like power tube distortion in my "clean" amp. Its my personal preference. Contrarily, blues players will usually go the opposite way, and try to get tone by breaking-up the power tube section earlier.

McCheese wrote: There's a bit here on biasing and stuff, it's aimed at owners of Fender Hot Rods, but it should give you an idea

http://studentweb.eku.edu/justin_holton/bias.html

Great link McCheese. Thats one of the better biasing references I've read. I like the advise of the 7581A/KT66 substitution, for the 6L6GC. Makes my Twin a monster( using quad set of GT KT-66HP hardness-"10").
I was barley able to get the red glow out of the plates when biasing with those!

http://thetubestore.com/powertubeinfo.html

Treena

Treena Foster wrote: http://thetubestore…

Treena

Thanks Treena, thats another good link.
I've bought some hard to find power tubes from them for my old Gretch 6156 amp.

Thanks to everybody for hte help, clay.