Seymour Duncan’s Twin Tube series are tube powered preamp/overdrive pedals.  They come in three flavors: “Blues”, “Classic”, and “Mayhem”!  Each of the two-channel pedals are powered by a pair of mil-spec (Military Spec), subminiature (very small), USA-made Phillips-Sylvania® dual triode tubes. According to Duncan, “Too often, inexpensive tube gear runs…... Click for more