Stereo 20W Class D Audio Amplifier - MAX9744

Boost your audio setup with this compact 20W stereo amplifier! This slim and efficient board features a class D amplifier that can drive two channels of 4-8 ohm speakers at 20W each. Simply power it with 5-12V DC through the onboard DC power jack and connect your stereo line-level audio source via the 3.5mm stereo headphone jack for high-quality sound. Thanks to its class D design, the amplifier runs cool without the need for heat sinks and operates with up to 93% efficiency, making it perfect for portable or battery-powered projects.

The heart of this amplifier is the MAX9744 chip, which makes it easy to use. You can control the volume analog-style with a 1KΩ potentiometer (included), or, for more advanced control, use I2C commands to adjust the volume in 64 steps through a microcontroller.

Key features of the MAX9744 include:

• Power input: 4.5V-14V DC
• Efficiency: Up to 93% (88-93% typical)
• Low quiescent current: 20mA (or 1µA in shutdown mode)
• Maximum gain: 29.5dB
• Line-level input: DC or AC coupled, up to 3Vpp
• Output: 20W stereo (at 4Ω, VDD = 12V, THD+N = 10%)
• Low THD+N: 0.04%
• Integrated click-and-pop suppression
• Protection features: Short-circuit and thermal overload protection

We’ve packaged this awesome chip into a user-friendly breakout board with polarity protection, jacks, terminal blocks, and I2C level shifting. There’s also a spot to solder a volume potentiometer for easy manual control. The board is fully assembled and tested, and we’ve included 3 x 2-pin and 1 x 3-pin terminal blocks, a 470µF power filter capacitor, and the 1KΩ trim pot for volume control.

A bit of soldering is required to attach the terminal blocks and components, but it’s quick and easy—expect to spend less than 15 minutes assembling the board. Check out our detailed tutorial for step-by-step instructions on how to assemble and use the amplifier.

Technical Specifications:

• Dimensions: 54mm (L) x 41mm (W) x 2mm (H)
• Weight: 11g
• Terminal Blocks: Blue or black (may vary)

With this board, you can easily add a powerful, efficient, and customizable stereo amplifier to your Arduino or other microcontroller projects. Perfect for driving speakers with minimal heat and power consumption!