PAM8403 Mini Class-D Stereo Amplifier Module, 2×3W Audio Amp Board, 2.5–5V DC Supply for DIY Speakers

Add clear stereo sound to your DIY projects with the PAM8403 mini Class-D amplifier board, a compact and efficient 2×3W audio amplifier module designed for low-voltage power systems. This “super mini” amplifier is a popular choice for portable speaker builds and embedded audio projects because it can run directly from 5V USB power or small battery packs while delivering strong volume for small speakers.

The PAM8403 is a Class-D amplifier, meaning it uses a high-efficiency switching design that wastes less power as heat compared to older linear amplifiers. That makes it ideal for battery-powered devices, small enclosures, and projects where heat and power consumption matter. It is commonly used in DIY Bluetooth speaker builds (paired with a Bluetooth audio receiver module), Raspberry Pi audio add-ons, small arcade cabinets, toy upgrades, intercom prototypes, and any project that needs a small stereo amplifier without a large power supply.

Wiring is straightforward: connect your audio source to the left and right input pads (L and R) along with ground, then connect your speakers to the output pads. Because these boards typically use bridge-tied load (BTL) outputs, each speaker uses two output pads and does not share a common negative terminal—this is normal for Class-D BTL designs and helps deliver higher output from low voltage. For the best audio quality, use a clean power supply and keep input wiring short and away from noisy power lines. If you hear noise, adding proper grounding, using a filtered 5V source, and ensuring your audio source volume is not set too high (causing clipping) can help.

Specifications (typical for PAM8403 amplifier modules)

• Amplifier IC: PAM8403 Class-D
• Channels: 2 (stereo)
• Output power: up to 2×3W (depends on supply voltage, load impedance, and distortion limits)
• Supply voltage: 2.5V to 5.5V DC (commonly used at 5V USB)
• Speaker impedance: typically 4Ω to 8Ω recommended (check your speaker rating)
• Efficiency: high (Class-D switching design, low heat generation)
• Inputs: L, R, GND (analog audio input)
• Outputs: L+ / L− and R+ / R− (BTL speaker outputs, no shared ground)
• Board size: ultra-compact “mini” PCB (varies by batch)
• Use case: portable speakers, embedded audio, DIY sound systems

This module is best suited for small speakers and moderate listening distances. For larger speakers or higher power systems, a higher-voltage amplifier may be needed. But for compact stereo builds, the PAM8403 delivers an excellent balance of size, efficiency, and sound output.

Included: 1× PAM8403 mini stereo amplifier board. A simple, cost-effective upgrade for any DIY project that needs clean amplified audio from a low-voltage supply.