Murrelektronik Propotional Amplifier. MurrElektronik propotional amplifier regulates the current supply to a proportional valve. The current is proportional to the set-point on the amplifier's input. A voltage output of 10 V is available for set-point adjustment. Features and Benefits. Status LED. Control electronics for proportional valves. Screw terminals. Start-up: 10 s. 35mm DIN Rail mounting