I never think of the 5500 machines as true A series Teacs, more like the red headed stepchild of the A series. They were kind of going in a different direction, not sure why they used the A series moniker. The top of the line 1/4 track stereo home use machine for the true A series (meaning belt drive, ac motor, right side single capstan machines) in the 7" format really was the A-4300. The 5500 machines were to the Teac A series what the Tornado was to the Oldsmobile division. Yeah, technically the Tornado was an Olds, but it wasn't like any of the others in the series and most of the parts weren't interchangeable with the others.