The K&K Sound 110-220V High Gain Noiseless Power Supply is specially designed to run K&K's high-gain preamps such as the Quantum Blender and the Pure XLR Mach 2. Regular power supply adapters have a 60 Hz hum, this power adapter has a noise suppression filter to provide noiseless operation. It works on 110 to 220 volts AC and comes with US prongs.