Well, I take it that your triple question marks mean you're surprised. and I'll take it further as a good kind of surprise. Until now I've been a little skeptical that the pentode would sound as good as a good triode but that might be because of my own unimpressive results from the newbie shallows years ago. Since then I've seen enough good reports that it seems worth a fresh attempt, especially now that Schadeability is there. Thanks Dave.