The Dominator 25 Bass is identical to the Dominator 25 AP except that it has a 15″ bass driver rather than a 12″ driver. It’s powered by a pair of EL84 valves. It dates from the late 1970s and appears in the “Sound Like WEM” brochure dated July 1978. It’s a well made amp that sounds good. The pictured amp is part of my collection (as from April 2016).