Carver: PM1.5 vs PM 1.5A

1.5A has an extra set of outputs (2 extra transistors) per channel, has an extra fan (2 instead of 1). Also, and I could be wrong on this, the transformer may be slightly larger on the 1.5A. If your interested I can dig up a PM1.5 and PM1.5A circuit board and snap a photo of each.