Take your best guess, there are no markings on it. It could possibly be a kit or this old geeze built them. The one with all the meters appears to be the power supply for the amp. The amp plugs into the wall and then there is a cable which interconnects to the amp/pre/power supply. My guess is that it is for Sound Reinforcement with the Kenner Close N Play. He had the Rek O Kut wired to these units.