PURPOSE: To avoid the noise caused by switching of the switch by switching first only the general circuit change-over switch and then securing the switching of the magnetic head circuit change-over switch after the bias oscillation output becomes zero in case the sound record is switched to the reproduction.
CONSTITUTION: Outer cases 22 and 32 of 1st and 2nd change-over switches 21 and 31 are fixed to substrate 41. Linkage component 42 possesses notch part 42a, and hooking component 44 is adhered to substrate 41 with pawl 44a provided at the middle part. Switches 22 and 32 are used for switching of the general circuit and the magnetic head circuit respectively. The 1st and 2nd movable bars 23 and 33 are at the right end each, and pawl 44a engages switching part 42a to lock up component 42 and bar 33 each. Under these conditions, bar 23 is shifted into direction A to switch the 1st and then 2nd switches in coupling. In this case, component 42 is at the hooking position, and then pawl 44a is detached from notch part 42a. At the same time, bar 33 is also set free to secure the reproduction mode. In such way, the noise caused by switching can be avoided.