PWM fader experiment using a CD4066

I wanted to experiment with an audio fader based on the use of 2 analog switches. The switches are used to either choose the signal from source 1 or the signal from source 2 and connect it to a buffering op-amp.

This short clip shows the circuit on a bread board and the signal traces of the pwm signal controlling the 2 switches. In the background you can hear the audio fading from one signal source to the other and back while the PWM signal is varied. I used an arduino nano to control the switches. The PWM frequency is about 64kHz.