Can voltage division be a applied to an electret microphone signal (around 40mV)?

Thread Starter

abdulwahab.hajar

Joined Jun 14, 2016
93
I was designing a transistor amplifier to amplify the signal of an electret microphone, throughout my simulations though I assumed my input voltage would be around 10mV rms as that is what research had told me about the output of an electret microphone...
However, while testing I found out that the microphone outputs a signal in the range of 40mV rms......
and my amplification gets distorted....

Attached is both the distorted and un-distorted outputs...
I tried re-configuring the resistances but to no avail, even when I decrease the gain when the input is 40mV rms, I still get some distortion...
So I was thinking of dividing the input signal by series resistances, is it possible?
if not any suggestions would be gladly welcomed..
 

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Thread Starter

abdulwahab.hajar

Joined Jun 14, 2016
93
hi ah,
What are the collector and emitter DC voltages, ie: without any input signal.?
E
Yeah, Vce was 3.788V... thanks for noticing, I configured the biasing resistors to get a Vce of 6.16V to place it nearer to the center of biasing region... although it's better I still get distortion at an input of 40mV... any ideas? :)
I tried using your addition to the design, funny thing is... Multisim still shows me distortion.. are you using a 40mV input source?
 
Last edited:

KeithWalker

Joined Jul 10, 2017
422
I was designing a transistor amplifier to amplify the signal of an electret microphone, throughout my simulations though I assumed my input voltage would be around 10mV rms as that is what research had told me about the output of an electret microphone...
However, while testing I found out that the microphone outputs a signal in the range of 40mV rms......
and my amplification gets distorted....

Attached is both the distorted and un-distorted outputs...
I tried re-configuring the resistances but to no avail, even when I decrease the gain when the input is 40mV rms, I still get some distortion...
So I was thinking of dividing the input signal by series resistances, is it possible?
if not any suggestions would be gladly welcomed..
Change the collector load from 9 Kohms to 4 Kohms. That will change the no-signal collector voltage from 4.8 volts to 7 volts allowing the output at the collector to go + and - 5 volts without clipping.
 
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