debouncing a 4066 switch?

Indeed there will.

So-called 'Fourier clicks'.

Graham

Probably what is happening is that the audio is changing from a non-zero amplitude to a zero amplitude in a very quick time(much very easy for your transistors to handle). So esentially what your getting is something like a jump discontinuity when your switch changes. (if the clicks sound different then this is probalby what is happening)

Now there are several cures for this and I don't remeber the names(something like zero axis switching or something) but the concepts are pretty easy.

Basically only switch the audio when its amplitude has crossed/near 0 so there is no jump(or very small as not to be heard)

or you could use some way to make the audio be critically damped so it ramps down slowly instead of quickly. A sorta fade to 0 but fast enough so you don't hear it.

Theres probably some other methods but I think the two above are easy to implement and understand.

Jon

This was about my first ever digital project, around 1975 or so... And I learned then that 4066 are tricky things. Even when you switch at the zero crossings, and remove the DC bias, and attempt to switch 'slowly' you will get clicks. Part of the problem is that the 4066 already has significant gain on the control lines, so switching the control input 'slowly' still switches the output 'fast'. But the major problem is the charge you inject into the switches from the control gates. No matter what you do, that still introduces clicks. Either use the other suggestion of controllable gain stages, or use some of the newer switches designed specifically for this purpose.

If it is indeed a speaker-level signal you are going to switch, the 4066 is not suitable at all (I think :-)

I usually had control feedthrough problems with the 4066, and typically opted for the 4016 instead. The 4066 looks better on paper, but the 4016 worked better for me. True, the 4016 has higher resistance (and distortion), but you can put it in a high-Z path where neither is a problem. (The distortion specs are based upon the device carrying a lot of current. Less current = lower distortion.)

Worked for me!

Bob Masta dqatechATdaqartaDOTcom D A Q A R T A Data AcQuisition And Real-Time Analysis

Not a problem, if you like flames and small explosions.