A D.C. motor control system of the closed loop regulating type is disclosed. The system includes a timed speed reference circuit with means for clamping the same to hold the speed reference voltage change at a rate that corresponds to the rate of motor speed change when armature current limit action occurs during acceleration and deceleration periods of the motor. A speed error spill-through circuit is also provided to increase the proportional speed gain of the system when the speed error increases beyond a given percentage of base speed to afford improved damping characteristics and reduce overshoot or undershoot of the overall motor drive.