I have a problem with audio going from input to output with pops of audio when CD4066 switch is off by the 7555 timer. The audio input is less than 100 millivolts. I don't know if the cd4066 is faulty since I had it for over 20 years. It's a CMOS chip and I don't take any precautions with static when I handle it. I tried different gates on it but I still have the same problem. I think the data sheet recommends 10,000 ohms as the load and I have 47000 ohms. The input is coming from a mixer and the output is going to an amplifier. I am using a 9 volt battery as the power supply. The timer turns on the cd4066 for approximately 1 hour to transfer the line signal. The whole circuit only uses about 50uA. There is a 47 microfarad bypass capacitor for the power supply. The main reason I want to build the circuit is to use it as a sleep timer. I only have one of these chips and it's expensive on eBay so I can't try another one to see if the problem persists.