Got one of the Cat O Nine drivers but didn't manage to get a jack to match that tiny little external socket on the side. Decided to toss the socket and solder on a couple of leads that could connect with my control panel. Now here's the trick: the socket has three connections and it's set up so that inserting a jack in the socket connects two of these. After you solder on plus and minus leads for whatever external power supply you're using, solder a jumper between the outermost two pins or the damned thing won't work.