I have emgs actives and a tone pump pre. The pre is attached to a barrel jack (stereo) for the hot wire. I have to change the jack to a top mount style which I have (also stereo). I'm not sure as to which wire goes to which lug. 3 wires, (hot. Ground, battery ) and 3 wires, which wire goes to which lug and how do I know what lug is which?