Electret Microphone Amplifier — MAX9814 with Auto Gain Control

$40.5 $78.57
Add an ear to your project with this well-designed elec­tret micro­phone ampli­fi­er with AGC. This ful­ly assem­bled and test­ed board comes with a 20–20KHz elec­tret micro­phone sol­dered on. For the ampli­fi­ca­tion, we use the Max­im MAX9814, a spe­cial­ty chip that is designed for ampli­fy­ing elec­tret micro­phones in sit­u­a­tions where the loud­ness of the audio isn’t predictable.This fan­cy micro­phone ampli­fi­er mod­ule is a step above the rest, with built in auto­mat­ic gain con­trol. The AGC in the ampli­fi­er means that near­by ‘loud’ sounds will be qui­et­ed so they don’t over­whelm & ‘clip’ the ampli­fi­er, and even qui­et, far-away sounds will be ampli­fied. This ampli­fi­er is great for when you want to record or detect audio in a set­ting where lev­els change and you don’t want to have to tweak the ampli­fi­er gain all the time.The chip at the heart of this amp is the MAX9814, and has a few options you can con­fig­ure with the break­out. The default ‘max gain’ is 60dB, but can be set to 40dB or 50dB by jumper­ing the Gain pin to VCC or ground. You can also change the Attack/Release ratio, from the default 1:4000 to 1:2000 or 1:500. The ouput from the amp is about 2Vpp max on a 1.25V DC bias, so it can be eas­i­ly used with any Analog/Digital con­vert­er that is up to 3.3V input. If you want to pipe it into a Line Input, just use a 1–100uF block­ing capac­i­tor in series (100uF sounds best). TECHNICAL DETAILSBoard Dimen­sions: 26mm x 14mm / 1″ x .6″EagleCAD PCB, Fritz­ing object, datasheets and more in the tuto­r­i­al
Sound

Sound