U.S. Patent No. 3,493,879 - 02/03/1970 - Gerald Stanley
Comments Concerning the Patent Gerald Stanley 03/03/2003: "The DC300 was the first reliable large solid-state amp and this patent reveals how it was done.  The patent would have been more aggressive in its claims were it not for taking an erroneous translation of a foreign patent cited by the examiner as substantive.  Lesson learned... always get a second translation."