> I connected pic with max4066 analog chip. the problem > I found is that 4066 needs voltage on output to operate > which we do not have it my question is this is there any part that can > be used to mute the analog line "audio" beside relay ? > any help will highly appreciated. You can use the 4066, you just have to follow the rules. The signal voltage must always be inbetween the supply voltages. I'm betting you used only 0V (ground) and +5V. If you run a line level signal into this, you'll find horrible distortion, because the analog voltage levels are - (someting) to +(something) It's the -(something) part that's getting you in trouble. Solution #1: Connect VEE to a low negative voltage, at least 1.5V, -5 would be ideal. Solution #2: Capacitively couple the signal in and out of the circuit, and on the input side, use a pair of equal value resistors, say 10k, to bias the 4066 to 2.5V.