Hi Sparkfun Community,
I am using the Analog MEMS Microphone Breakout Board (SPH8878LR5H-1) for audio input into a line level recorder. Unless the sound is coming very close to the mic it is too quiet.
Does anyone know if there is a way to increase the gain on the Op Amp Circuit? Looks like I would have to swap out an SMD component to do so, any advice or pointers? I like the quality of the audio but just need to be able to pickup quieter sounds too.
Thanks in advance for any guidance!
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To increase the gain, increase the ratio R4/R3. R4 = 300K for x64, R4 = 1Meg for x213.
You may run into oscillation or stability problems if you increase the gain too much, as the gain-bandwidth product of the OPA344 is only 1 MHz.
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Awesome, thank you! So I should be able to just replace R4 with say a 500K (ie. 504 code SMD) and it should increase the gain a bit?
In that case, use a gain of 1, not 0. Replace the feedback resistor with 4.7K.
Hint: gain = (output voltage)/(input voltage)
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