Getting constant volume (sound) level at o/p even i/p level is increased/decreased

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Joined Jul 6, 2011
Please help in a project which can give constant level of volume at its output whether the input volume level is increased/decreased (within certain limits) and microphone should act as input device.
The out put volume level should be automatical maintained at fixed pre-determined level without any manual adjustment required.

P.S.- Please start from very basic and speacial consideration towards power consumption


Joined Dec 26, 2010
Last edited:


Joined Nov 30, 2010
The words, "automatic level control" or "automatic gain control" are good ways to start. I played with some of those chips 30 years ago when I worked with a band. (They aren't very good for musicians.) Let's see...NE570 or SA571 compandor. There's a cute word. compressor-expander = compandor
I don't think Signetics makes those any more.
H*** I'm so old I don't even know if Signetics exists any more!