Golden Ear Triton One. And you can get a new pair let alone used at the $5000 mark. I use solid state so I am in no position to recommend anything in the tube amp world. I can tell you the Triton's are good-very efficient (92db) so should be easy on the tubes. Also, if I'm not mistaken, Sandy Gross, President of Golden Ear, uses a tube setup with his Triton's.