ET-S73
MAX9814 AGC Microphone
Microphone amplifier with automatic gain, analog out
AED 25.00
Out of stockOverview
Microphone amplifier with automatic gain, analog out
The ET-S73 is built around the Maxim MAX9814 — low-noise preamp + VGA with automatic gain control, 40/50/60dB max gain. It connects over Analog audio out (DC-biased) to any ADC and is powered from 2.7–5.5V, ~3mA.
Designed in Dubai by ElectroTrical — the full schematic, BOM and design notes are published below.
Good for
- Sound-reactive LEDs
- Clap and noise triggers
- Voice recording with an ADC
Key features
What makes it different
Amplifier
Maxim MAX9814: low-noise preamp + VGA with automatic gain control, 40/50/60dB max gain
Microphone
Analog MEMS mic, bottom port, powered from the low-noise MICBIAS
Interface
Analog audio out (DC-biased) to any ADC
Supply
2.7–5.5V, ~3mA
Open documentation
Schematic, BOM and layout notes published for every board.
Breadboard friendly
Standard 2.54 mm pitch and M2.5 mounting holes.
Specifications
Technical specifications
| Amplifier | Maxim MAX9814: low-noise preamp + VGA with automatic gain control, 40/50/60dB max gain |
|---|---|
| Microphone | Analog MEMS mic, bottom port, powered from the low-noise MICBIAS |
| Interface | Analog audio out (DC-biased) to any ADC |
| Supply | 2.7–5.5V, ~3mA |
| Size | 25.4 × 17.8 mm |
|---|---|
| Mounting | 4 × M2.5 holes, 2.54 mm from each corner |
| Connectors | 6-pin 2.54 mm header |
| Main IC | MAX9814ETD+T (LCSC C41714) |
| Revision | Rev A |
| Libraries | analogRead sampling, ESP32 I2S-ADC, Arduino FFT / sound-reactive LEDs (WLED analog mic) |
|---|
Performance
Gain
Pinout
Pin map and connections
| Pin | Name | Type | Function |
|---|---|---|---|
| 1 | VIN | Power | 2.7–5.5V |
| 2 | GND | Ground | Ground |
| 3 | OUT | Power | Audio out, ~1.25V DC bias, 2Vpp max |
| 4 | GAIN | Signal | Float = 60dB · GND = 50dB · VIN = 40dB |
| 5 | A/R | Signal | Attack/release ratio (float = 1:4000) |
| 6 | SHDN | Control | Low = shutdown (pulled high) |
Mechanical
Dimensions and what's in the box
In the box
- 1 × ET-S73 MAX9814 AGC Microphone (assembled)
- 1 × 6-pin 2.54 mm male header, unsoldered
Getting started
- Wire the header: VIN, GND, OUT, GAIN, A/R, SHDN
- Libraries:
analogReadsampling, ESP32 I2S-ADC, Arduino FFT / sound-reactive LEDs (WLED analog mic)
Compare
Which audio board?
| MAX9814 AGC Microphone (this board)This board | ET-A21 MAX98357A I²S 3 W Amp | ET-S47 ICS-43434 I²S MEMS Microphone | |
|---|---|---|---|
| What it does | Microphone amplifier with automatic gain, analog out | Digital audio straight to a speaker — no DAC needed | 24-bit digital microphone for ESP32 and Pi |
| Interface | Analog audio out (DC-biased) to any ADC | I2S / left-justified / TDM, 8–96kHz, no MCLK… | Standard I2S (Philips), slave: host provides… |
| Best for | Sound-reactive LEDs | ESPHome voice assistants | Voice and audio capture on ESP32 |
| Price | 25 AED | 19 AED | 22 AED |
Downloads
Documents and design files
Need a custom version of this board?
Different connector, size or sensor? We design and build custom variants.