This is an old tube amp from the 40's. It's got the OT mounted on the speaker, with 2 wires going into the speaker. Also, it has a set of wires going into the speaker magnet, then into the driver, as well as a ground wire attached to the frame. Does anyone know anything about this? As far as I know it's not a field coil speaker, just a regular alnico but I could be wrong. Thanks!