Ok, so maybe I did something wrong... maybe.
I took this step down transformer and took out the 2 stock resistors. I put a jumper where one resistor was and installed a variable resistor where the other was. Plugged it in and POP!!!! blue smoke, HOLY CRAP!! Fire! lol, extremely exciting.
What did I do wrong???
I tested the variable resistor and the centre leg is the wiper and the other 2 legs are either side of the resistor. I used the back leg so the further out the adjustment screw was the lower the voltage, turn it clockwise and the voltage increased. the unused leg is the one you see sticking out of the variable resistor.