PURPOSE: To decrease the number of operating buttons and then simplify the operating panel, by giving a control to provide another function to an operating button in addition to its primary selecting function.

CONSTITUTION: When the forward-turn switch 10 is pushed while the sound record switch 15 is pushed consecutively, the differential pulse of a differentiating circuit consisting of the resistances R7 and R8 plus the capacity C2 is put into the latch circuit FF3 through the inverter 23 and NAND circuit 21. Thus the record signal is delivered from the OR circuit 20 to hold the recording mode. In the recording mode, the switch 15 functions as a safety switch in the course of recording, and the switch 10 functions as a recording switch under recording. Under these conditions, the switch 10 is pushed again. Thus the circuit FF3 is reset to give no input to the circuit 20, and then the record signal stops its output. Accordingly the switch 10 functions as a cancel switch in the course of recording. On the other hand, the recording mode is cancelled in an exactly the same way also by pushing the stop switch 12 and reverse-turn switch 13 each.