Abstract: A stock feed apparatus for feeding strips of stock to or from a stock processing machine to maintain a loop in the stock. The feed means is arranged to feed stock to or from the loop at speed correlative with the amplitude of a control voltage applied to the motor control. The stock loop sensor produces a first digital signal when the loop exceeds a first limit and a second digital signal when the loop exceeds a second limit. A loop control circuit is operative in response to the first digital signal to apply a control voltage of a first preselected amplitude to the motor control to drive the feed apparatus at a first speed until the loop moves away from the first limit and responsive to the second digital signal to apply a control voltage of a second preselected amplitude to drive the feed apparatus at a second speed until the loop moves away from the second limit.