MAX9814 Electret Microphone Amplifier Module Auto Gain Control for Arduino

The MAX9814 is a high-performance, low-cost microphone amplifier featuring built-in Automatic Gain Control (AGC) and low-noise microphone bias. It automatically boosts quiet sounds and compresses loud audio to prevent clipping, making it perfect for unpredictable environments. It is ideal for Arduino, Raspberry Pi, or ESP32 voice projects.

The MAX9814 microphone amplifier module is a high-performance, low-noise amplifier with built-in automatic gain control (AGC). It is designed for audio applications such as voice detection, sound measurement, and voice-activated systems. The module features a built-in MAX9814 IC, a high-quality electret microphone, and supports adjustable gain control.

Ideal for use with Arduino and other microcontrollers, it provides clean analog audio output, even when the sound level varies greatly.

Features

• Built-in MAX9814 amplifier chip
• Automatic Gain Control (AGC) for consistent output levels
• Wide supply voltage: 2.7V – 5.5V
• Adjustable gain: 40dB, 50dB, 60dB (via pin jumper)
• Output: Analog audio signal
• High sensitivity and low noise
• Compact PCB with onboard electret microphone

Getting started with MAX9814 Microphone amplifier Module AGC

In this project we are going to demonstrate how to use the MAX9814 microphone amplifier module with an Arduino to create a sound-reactive LED. The LED’s brightness changes in response to detected sound levels, creating a simple audio visualization effect. Feel free to go beyond this example, even including Machine Learning (ML).

Hardware Requirements

• Arduino board (Uno, Nano, or compatible)
• MAX9814 microphone amplifier module
• LED (built-in or external)
• Current-limiting resistor (220-330Ω for external LED)
• Breadboard
• and jumper wires

Connections

1. MAX9814 to Arduino:
   • OUT → A0
   • VDD → 5V
   • GND → GND
   • GAIN pin settings:
     • Ground (GND) = 40dB gain
     • VDD (5V) = 50dB gain
     • Floating = 60dB gain (default)
2. LED:
   • Connect to a PWM-capable pin (suggested pins: 3, 5, 6, 9, 10, or 11)
   • Remember to use a current-limiting resistor (220-330Ω)
   • Example: LED positive → pin 9, LED negative → GND via resistor

Package Includes:

1 x MAX9814 Auto Gain Control Stable Microphone Amplifier