Is 12B4/A good for differential pair?

[leadbelly]

Well, I didn't know whether to tack this on to one of the existing 12B4 threads, but as they seem focused on line stages, I thought it might be threadjacking.

So, basically, as the 12B4 is getting rave reviews as a low gain single ended line stage, my question is "would it also give good results in a differential stage with a higher gain (say 20)"? I have yet to come across any schematics for such an application. I guess the problem is with its low mu, you need several to get the required gain and that seems inelegant/wasteful?

[bst]

Check out Levinson's article, "1.5 watts of pure single-ended triode power!"

http://www.enjoythemusic.com/magazin...2/levinson.htm

[leadbelly]

Originally posted by bst
Check out Levinson's article, "1.5 watts of pure single-ended triode power!"

Thanks for the great link, but what does that have to do with my question?

[EC8010]

Depends on what you want the differential pair to do. If you're looking for good CMRR, then a high-mu valve is better. If you need more gain than a 12B4 can provide, you'd do better with a 6SL7 or ECC83, then follow it up with DC coupled cathode followers.