The R1600-PSU Power Supply from Radial Engineering is an external power supply unit for the Firefly Tube Direct Box. It helps to reduce noise and delivers ±16V (1600mA) that is internally stepped up to 48V for the tube. This power supply will accept input voltages from 100 to 240V, thus enabling the Firefly to be used in various countries. It comes with the appropriate power cable to comply with local electrical systems.