Hi Dan, and welcome. The archives here will give you a direction on which designs to try but the Theatre and Thermionics are the most tube friendly. I have built Theatre 4's and 2 Pi's. You've probably seen the "you have mail" posts from Wayne. He'll e-mail you the plans. Your opinion on the Qts of the Delta 15 is great because not only is it an "I told Wilbur and I told Orville..." sort of thing 'cause so many of us love the bass response of the Delta but because some of the participants, and Wayne, are in a position to debate that point. I'm not. I turn big pieces of wood into smaller pieces of wood.