A high-speed actuator moves a valve stopper to a selected position to control material flow. The actuator includes a rod carrying first and second axially spaced solenoid armatures attached to the stopper. First and second solenoid coil surround and are spaced from the rod to bias the first solenoid armature along with the rod and valve stopper. A linear variable differential transformer (LVDT) responsive to the position of the second armature determines the instantaneous position of the valve stopper. A valve position control circuit receives a valve position set point from a user's input, and a valve position feedback signal from the LVDT. The valve position control circuit includes first and second solenoid coil drive signals that urge the first armature and stopper to the valve position set point. A signal generator circuit vibrates the valve about a set point to enhance material discharge.