I only see six cubes in his artwork, and the cube he's holding in his ready animation looks more like a miniature Distortion Zone than a physical Dynamo. Plus, "Dynamo" had always referred to all six of the devices he made from the parts of the AI unit he salvaged by the same name before that point.
oops i counted wrong. Also for Dominator dynamo does not only reflect his weapon as he made a dynamo factory.