Bluetooth Amplifier Board AUX Audio Input Power Amplifier Board 3.7V

In this review the author tested the Bluetooth Amplifier Board to see if it delivers usable audio power for DIY speaker projects. The board is clearly aimed at hobbyists and small speaker builders who need a compact, low-voltage solution: it uses Bluetooth 5.0 and runs from a 3.7V lithium cell or a 4.5 to 5V regulated supply. The single biggest reason to buy is straightforward: it can drive two small speakers with up to 5W per channel when provided with adequate current, giving an easy way to add wireless input and modest amplification into battery-powered enclosures.

Key Features

• Bluetooth 5.0: Provides a modern wireless input with reliable pairing and lower latency than older modules, useful for streaming from phones or media players.
• Low voltage operation: Runs from DC 3.7V to 5V so it integrates directly with single-cell lithium batteries or common 5V regulators for portable designs.
• Configurable output: The board can be set up to provide two channels at 5W each when fed with sufficient current and matched 4 ohm speakers, enabling a stereo pair in a compact PCB form.
• External amplifier option: Has an OUT audio output on a 3P block for easy modification to drive a larger external power amplifier if more volume is needed.
• Hands-free and button support: Supports call handling and external button connections for play/pause and track control in integrated speaker builds.
• Micro power switch control: Simple onboard switching makes power management straightforward for battery-powered projects.

Who It's For

This board is best for electronics hobbyists, makers and small-scale speaker builders who want a compact Bluetooth front end with modest amplification for DIY projects. It fits projects where space is limited and where a single lithium cell or a 5V regulator is the intended power source.

It is less suitable for audiophiles or anyone who needs high-fidelity, high-power output for large rooms. Buyers who require more than 5W per channel or very low distortion should pair this board with an external amplifier via the provided OUT terminals or choose a higher-power amplifier module instead.

Pros & Cons

Pros

• Compact PCB design makes it easy to fit inside small enclosures and custom speaker boxes.
• Works from a single-cell lithium battery or a 5V supply, simplifying portable builds.
• Includes Bluetooth 5.0 and hands-free support, adding modern wireless convenience and call handling.
• OUT audio output lets builders expand to an external amplifier when more power is needed.

Cons

• Requires a robust power source (1.5A to 2A or higher) to reach full output, so battery selection and wiring matter.
• Not intended as a high-end audio solution; sound quality is appropriate for casual listening and portable use.

Specifications

Brand	Sanpyl
Bluetooth	5.0
Voltage	DC 3.7V to 5V
Current	1.5A to 2A (recommended)
Max power	10W total (5W x 2)
PCBA size	approx. 40 x 34 x 9mm (including terminal)
Package weight	approx. 40 g

Our Verdict

The Bluetooth Amplifier Board is a practical, affordable module for DIY speakers and portable audio projects that need wireless input and modest output. It offers modern Bluetooth 5.0, simple battery operation and an option to feed an external amplifier, making it good value for makers who prioritize compact size and flexibility over high-end sound.

Frequently Asked Questions

What battery voltage does it need?
The board runs on a single-cell lithium battery at 3.7V or a regulated 4.5 to 5V supply; ensure the battery can deliver 1.5A to 2A for two speakers.

Can I connect larger speakers?
You can use the OUT audio terminals to feed an external power amplifier for larger speakers; the onboard amp is designed for 4 ohm small speakers up to 5W per channel.

Does it support call controls?
Yes, the module supports hands-free calling and external button connections for basic playback and call functions.