The standard output of hub dynamos is 6V A.C. and usually 3W, though smaller current outputs are available.
I think it is unlikely that your hub deviates from this well established standard, else it would be incompatible with almost all lights and charging accessories. Of course, as original equipment, the best place to ask the question is your CUBE dealer or the CUBE helpdesk.
You could also hook up the output to an oscilloscope and see what you get out of it. You should expect a sine wave (from an unloaded SP dynohub) or something a bit more triangular maybe. As Chris H demonstrates, the output is 12-15V peak-peak AC with frequency apparently dependant on wheel speed and the design of the hub.