Most people think that you do need a step down transformer for the System 1's and 80's, but in the manual for these machines, it clearly shows the wiring change for 230V operation.
If you look at the image below, you will see the 110V transformer wiring, and then in a dotted box to the left you will see the change needed for 230V operation. This is the same for both System 1 and System 80 pinballs.
So basically, the two transformers are in parallel when in 110V mode, and in series for 230V mode.
For 230V operation: Active goes to the 115V input of the first transformer, link the Common of the first transformer to the 115V input of the second transformer, and the Neutral is connected to the Common of the second transformer.
