Fangrui Product Details Add An Ear To Your Project With This Well-designed Electret Microphone Amplifier. This Fully Assembled And Tested Board Comes With A 20-20khz Electret Microphone Soldered On. For The Amplification, We Use The Maxim Max4466, An Op-amp Specifically Designed For This Delicate Task! The Amplifier Has Excellent Power Supply Noise Rejection, So This Amplifier Sounds Really Good And Isnt Nearly As Noisy Or Scratchy As Other Mic Amp Breakouts Weve Tried! This Breakout Is Used For Projects Such As Voice Changers, Audio Recording/sampling, And Audio-reactive Projects That Use Fft. On The Back, We Include A Small Trimmer Pot To Adjust The Gain. You Can Set The Gain From 25x To 125x. Thats Down To Be About 200mvpp (for Normal Speaking Volume About 6 Inch Away) Which Is Good For Attaching To Something That Expects Line Level Input Without Clipping, Or Up To About 1vpp, For Reading From A Microcontroller Adc. The Output Is Rail-to-rail So If The Sounds Gets Loud, The Output Can Go Up To 5vpp! Using It I