"ITEM IS CALLED EQUALIZER, NOISE REDUCTION SYSTEM; SINGLE PROCESSOR UNIT WITH BUILT-IN CHANGEOVER FACILITIES, DESIGNED TO SERVE ONE RECORDER TRACK DURING BOTH RECORDING & PLAYBACK, WITH MONITORING OF LINE-IN OR THE ENCODED TAPE SIGNAL DURING RECORDING. THE OPERATING MODE IS SET BY PUSH-BUTTON SWITCHES ON THE FRONT PANEL. THIS UNIT IN MULTITRACK WORK IS FACILITATED BY THE BUILT-IN PROVISION FOR AUTOMATIC RECORD-PLAY CHANGEOVER, CONTROLLED FROM THE RECORDER"