I'll back up with Atmasphere stated, take a good look at tubes. The Heresy has horn mid and tweeter and is quite revealing, tubes should mate very well with it, and you don't need a hold lot of watts because of the efficiency of the Heresy. Paul Klipsch used tubes for what's it worth. Don't take my word for it, head over the the Klipsch forums and see the the Heresy owners there have to say.