I picked up a Kustom K200B four channel PA head. The back panel has three 1/4" jacks in it, two next to each other near top left, and one near bottom right. None are marked. I can't tell if there are one or two speaker outs, if there's a monitor jack, a pre-out/amp-in pair, a foot switch jack, or if they're just air holes so the poor little gremlins who make the loud by jumping up and down on the smoke components don't suffercate. I've tried the schematic, or so it says. It shows eight jacks. I count seven, four on the front for the four channels, and these unmarked three. Kustom is no help. They are not the company that built this. In fact, the previous Kustom isn't the company that built it either, ~1970. Anyone have one of these, or the manual thereto? I'd like to know what goes where, and if the pair is for speakers, what my impedance options are.