How to tell.....

Dear tube experts,

How to tell a TFK diamond bottom smooth plate tube is a 12au7 or 12ax7 if most of the letters are missing?

Thanks!

eugeneli10-17-2006 9:15pm

amandarae Details Discussions Posts This discussion Message User 512 posts 10-18-2006 at 04:13am Copy Comment URL Report Comment Edit Delete You need a tester.