Using electronic diagram below, through a single switch is possible to choose one of four separate stereo channels. Internal switch is made by CMOS components, to avoid cracking that usually occur in mechanical switches.
Two type D flip-flops IC2 were assigned a divider role by connecting outputs to D inputs . Q output of FF1 is connected to the clock input of FF2, resulting in a four-bit counter.
Gates outputs control switches of CMOS IC3 and IC4.
Entry to each switch includes a voltage divider to allow the switches to work in the linear range providing low distortion of audio signals.
The circuit will require a current of only 1 mA at a supply voltage of 5 V which can be increased to approximately 15V.