A control circuit is adapted to control the movement of a pintle relative to the die head of extrusion apparatus. A command signal is supplied to a signal generator, which produces a first output signal in the form of a series of continuous voltage triangles, and a second output signal in the form of unit pulses. An impedance matrix contains a plurality of potentiometers which may be remotely connected to a summing amplifier. The potentiometers are arranged in a numerical order. Odd-numbered potentiometers are supplied with the triangular output signal from the signal generator. Even-numbered potentiometers are supplied with the signal generator triangular output signal, but which has been phase-shifted by half the width of one triangle. The pulse output from the signal generator is supplied to a decoder, which successively connects pairs of numerically-adjacent potentiometers with the summing amplifier during overlapping time intervals. During the cycle of operation, only a pair of numerically-adjacent potentiometers will be connected to the summing amplifier at any point in time. The output of the summing amplifier is a control signal, which may be used to control the movement of a pintle relative to a die head.