Old school Lanzar Opti 50c with jacobs electonics accuvolt running constant 16.15 volts.. bought new in 1996 used it until 2004 and still ran solid. Found someone who wanted it more then me and sold it to him and a lanzar 4100 (another AWESOME amp).. The 50c was pushing 4 10" dvc's Lanzar DC series.. Great subs and ended up selling those to another person in 2004.. and were still in great condition even after them many years of abuse I gave em.. Still LOVE the 50c!! I called him up a few days ago in texas and is now pushing 4 12" db's I guess with it.