Can volume control be part of a pre-amp?

Because it may alter the operating characteristics of the preamp in ways you don't want. Such as the noise of the device.

But, you don't need a whole stage just to add a volume control.

Just have a pot hanging off the preamp stage to ground, and take the output from the arm.

Michael

Thanks, Michael! After looking at the datasheet more closely, I think I do need an extra stage. The GBWP of the opamp is only 200khz, so a gain higher than 20V/V already drops the bandwidth lower than 10,000kHz. I'm expecting the microphone voltage levels to be between 1mV to 10mV, so that would be pretty low.

By the way, can you clarify your last statement regarding the pot hanging off the preamp stage to ground? I'm picture a pot hanging at the pre-amp output connected to ground. Is this what you are saying?

Thanks!

The traditional way to connect a volume control is to ground one end of the pot and connect the audio out from the previous stage to the other end of the pot. The wiper of the pot then connects to the input of the next stage.

Was it on the back of a dunny door - maybe ?

Having variable gain ( using a pot or multi-way switch) IS the STANDARD way to make a mic-pre amp.

This way, headroom and signal to noise is always optimised.

....... Phil

Whose standard would that be?

Sean

"Sean"

...... Phil