I hear you Orpheus but I want to be sure I'm getting what I'm paying for. You can easily purchase tubes that sound great but may not measure up, its happened to me numerous times over the years unless you purchase from trusted dealers. Even one "repudable" well known dealer I purchased from sold me 4 small "NOS" dual triodes that went south in less than 2 years, all of them, we're not talking a hot circuit here either. I have numerous brands of this type in my catche with nary a problem and some still in the amp testing very strong after 6 years continuous use. Unfortunately this dealer came highly recommended so I didn't test prior to installation. I've never made that mistake again. Yes your ears can tell you plenty but a tester can tell you if you're getting what you're paying for so far as electrical parameters. Optimal performance requires testing periodically, trust me on this, you sometimes don't realize what you're missing until it becomes quite obvious, your hearing becomes acclimated.
