Hi,
Im having trouble with switch pop noice when I active channels. Its a big mixer with 20 stereo inputs and 12 mono.. The schematic only shows the four first inputs on the left side but you get the idea. I wanted to leave out all the 20K resistors when they are not in use to minimize the noice from them.. (there is a lot of them with 32 inputs..) therefore I placed the switch after them. The pop noice is only present first time I activate the channel.. If I mute the channel then active it again the switch pop is gone... Same goes for all channels the pop is only there the first time I switch.
Any ideas how the make the "pop" go away?
The mixer is used with keyboards/synthesizers.
Im having trouble with switch pop noice when I active channels. Its a big mixer with 20 stereo inputs and 12 mono.. The schematic only shows the four first inputs on the left side but you get the idea. I wanted to leave out all the 20K resistors when they are not in use to minimize the noice from them.. (there is a lot of them with 32 inputs..) therefore I placed the switch after them. The pop noice is only present first time I activate the channel.. If I mute the channel then active it again the switch pop is gone... Same goes for all channels the pop is only there the first time I switch.
Any ideas how the make the "pop" go away?
The mixer is used with keyboards/synthesizers.
No.
The value is not critical. 200k, 1Meg, whatever.
Rayma and I both overlooked that you have a single-rail supply. The opamp idles at half rail, VB. The capacitor bias must be half-rail. I initially posted what Rayma proposed, then saw my error, and changed my inage.
Not exactly. All resistors need to go to your "VB" since this is a single supply circuit. "Ground" in this case is actually the negative rail and bleeding to it will make a very big pop. When Rayma saz "ground", he means the bias ground which is "VB" in this circuit. He is thinking in terms of a typical op-amp circuit that uses a bipolar supply. Yours is not. PRR chose 200K instead of 1 meg because it is 10x the 20k resistors, but I would go with 1 meg.
