# Electret microphone signal amplification

What will be the output of these electret microphones? To be able to have a 3-4 Volts peak output, what should be the gain approximately?

P.S. : Unfortunately these are not products bought from a known seller and there are no part/model numbers etc. on them. I just wanted to know that whether there are a typical output voltage for these kind of microphones or not.

• What does the (required) data sheet tell you? Dec 10, 2019 at 16:04
• @Andyaka unfortunately these are not products bought from a known seller and there are no part/model numbers etc. on them. I just wanted to know that whether there are a typical output voltage for these kind of microphones or not. Dec 10, 2019 at 16:11

This one from Farnell (almost certainly not the one shown in the question) has a clue to the output level: -

That clue is inside the red box I added. It tells you this; if a 1 kHz sound signal of 1 pascal (RMS air pressure) is applied, the typical output voltage level is -41 dBV. And, -41 dBV is 8.91 mV RMS.

To get 3 or 4 volts peak requires amplification of about 280 times.

So, if you don't have a data sheet you are not going to be able to predict the amplification needed without performing a test.

I just wanted to know that whether there are a typical output voltage for these kind of microphones or not.

If it's important enough to know, plough through various data sheets from various suppliers and see what the spread of output levels is likely to be. Or just buy a microphone supported with a data sheet from a recognized supplier as most EEs would.

• thanks! I now at least an idea about where to look in datasheets of these mics. And also an example of the output voltage. The amplitudes of the incoming sound waves will alter the pressure on the microphone, so the output will be higher when it is louder right? Dec 10, 2019 at 16:21
• Correct and 1 Pa sound pressure equals 94 dB sound pressure level (another and more commonly used term). Dec 10, 2019 at 16:31