The House-GND kit is a simple circuit that helps reduce hum in audio equipment that is attached to a dirty house-ground connection. The diode bridge only connects the two grounds when the voltage difference between them exceeds about +/-1.4V. The small capacitor allows high-frequency noise to find a path to the house ground. The 10-ohm power resistor makes a DC connection between grounds, while still offering some isolation between grounds. The kit is quite small, the PCB being only 1 by 1.4 inches big. Includes all parts, including two hex standoff assemblies and instruction sheet.