PURPOSE: To prevent malfunctions by stopping a tape recorder when a playback switch is turned on in a backward direction right after a playback switch in a forward direction is turned on or in an opposite case.

CONSTITUTION: When the input terminals on one side respectively of NOR circuits NOR1, NOR2 go to an L level on turning on of a playback switch 12 in a forward direction right after turning on of a playback switch 13 in a backward direction, the output terminal of a NOR circuit NOR1 goes to an H level, transistors Q3, Q4 go on and differential pulse signals of an L level are supplied. Therefore, the differential pulse signals of an L level are supplied to the stop input terminal I.STOP of an LSI 11 by the effect of a differentiating circuit 40. The playback output terminal O.PLAY of the LSI 11 goes to an L level. In this time, the differential pulse signals supplied to the stop input terminal I.STOP end and even when the terminal I.STOP goes to an H level the differential pulse signals have ended at that time and therefore the terminal I.PLAY do not go to an L level and the tape recorder is stopped.