Abstract: The disclosure applies to an audio recording apparatus which receives audio signals, generally from a tape recorder, and forms grooves in a spiral pattern on a recording disk. The apparatus typically includes a turntable for rotating the recording disk, a cutter for cutting grooves in the disk, and a cutter transducer for modulating the instantaneous position of the cutter as a function of the audio signals. An electromechanical subsystem is responsive to control signals for directing the unmodulated position of the cutter; i.e., its unmodulated radial position with respect to the center of the disk and its unmodulated vertical position or depth. In accordance with the invention, there is provided a system for automatically generating the control signals which control operation of the electromechanical subsystem. When no modification of the unmodulated radial position is called for, none is made, thereby eliminating wasteful pitch modifications.