PURPOSE: To prevent the deteriortion of performance of a sound switching device and to transmit a sound signal with high quality, by delivering the sound signal selected by a fader amplfier only while a fader is working and by-passing said amplfier for output when the fader has the maximum gain.

CONSTITUTION: Sound input terminals 101∼110 are connected to an output line 121 of a cross point connected to a fader amplifier 122 and a buffer amplfier 123 by cross points 111∼120. The outputs of both amplifiers 122 and 123 are connected to a sound output terminl 125 via an output switch 124. This switch 124 is switched to the output of the amplifier 122 when the amplifier 122 does not have the maximum gain and then to the output of the amplifier 123 when the amplifier 122 has the maximum gain respectively. The fader control signal of the amplifier 122 is used for the switching of the switch 124, and the absolute output level of the amplifier 123 is set equal to that of the maximum gain of the amplifier 122. This prevents the deterioration of performance of a sound switching device. Thus the sound signal can be transmitted with high quality.