Suppose an audio amplifier has no any volume control option in its schematic but I need to control the volume level of the sound which come out through any woofer. How I can do it, please tell me ?
I should put a pot on the input of amplifier. Am I right ? Should I use 10k or 100k value pot ? Which one ? If I put the pot on the output of amplifier, what will be effect ?
The value of the logarithmic volume control depends on the input impedance of the amplifier and the output impedance of the music source. Usually a 10k volume control is fine.
You might need a coupling capacitor to block any DC at the input of the amplifier because the volume control must connect to ground but if the amplifier input has DC then it must be coupled with a capacitor.
It shows a dual potentiometer with both sections almost connected in parallel.
The blue wire is shorting both wiper terminals to ground, so it is used as a rheostat, not as a volume control.
It might be used to adjust the frequency of a Wien Bridge oscillator.
audioguru; The 1st two pics are from a forum. I can see them becase I am a member but you cant. The 3rd was just off the net and I used the Insert Image button above. How do you do the thumbnail pics? Andy
Thumbnails are made by clicking on GO ADVANCED and uploading an image from your pc.
I never saw the INSERT IMAGE button before. Let me try making a big image of my RC airplanes. **broken link removed**