Got a request for this one. It's a effects loop buffer that's a solid-state version of the Dumbleator effects loop buffer. It's equipped with an internal charge pump that converts a +9v supply to +33v. Very useful for keeping your effects loop free from signal-loss. Since it runs at a much higher voltage than most effects, make sure your components are rated at at least 50v. Also the 10Ω resistor off the +9v pad should be 1/2 watt or higher.