2 x 20W Class D Bluetooth Audio Amplifier Board - Compact 2x20W

In this review the TSA9840 2x20W Class D Bluetooth Audio Amplifier Board is assessed for hobbyists and small-system builders who need a compact, protected stereo amp with wireless input. The bottom line: it is a space-efficient amplifier module with integrated Bluetooth 4.0 that delivers a reliable 20W per channel and essential protections, making it ideal for DIY speakers, desktop audio upgrades, and compact home theater projects. The review examines sound architecture, connectivity, build size and voltage range to show where it fits best.

Key Features

• Compact footprint: The small 9.1cm x 5.0cm board fits into tight enclosures and kits without sacrificing mounting options.
• Bluetooth 4.0 integration: Built-in Bluetooth audio lets users stream from phones or tablets without adding a separate receiver module.
• 20W per channel output: The Class D design based on MAX98400A provides efficient power delivery suited to bookshelf speakers and low-power home audio setups.
• Wide working voltage: Operates from DC10V to 24V so it can be paired with a range of adapters or battery systems for portable projects.
• Protection features: Thermal and output current protection help prevent damage under heavy load or poor ventilation, improving reliability in long runs.
• Bluetooth volume control port (BVC): The BVC header gives an easy way to add remote or panel volume control for finished builds.

Who It's For

The TSA9840 is best for DIY audio builders, makers creating compact powered speakers, and hobbyists upgrading small amplifiers who value efficiency and simple Bluetooth streaming. Its small size and 20W per channel output work well in desktop systems, portable speaker enclosures, and low-power home theater surrounds.

It is less suitable for high-power stereo systems or listeners who demand audiophile-grade components and large headroom; those users should seek higher-wattage or discrete component designs. Also, buyers needing onboard digital inputs beyond Bluetooth should consider a board with additional input types.

Pros & Cons

Pros

• Compact, space-saving board size that installs easily in small enclosures.
• Integrated Bluetooth 4.0 for straightforward wireless streaming without extra receivers.
• Efficient Class D topology based on MAX98400A provides good power per channel with low heat under normal conditions.
• Built-in protections increase long-term reliability in DIY builds.

Cons

• Not intended for high-power or audiophile systems where larger amplifiers and discrete components are preferred.
• The module focuses on Bluetooth audio and may require additional boards or wiring for multi-source input flexibility.

Specifications

Model	TSA9840
Channels	2 x 20W
Amplifier type	Class D (based on MAX98400A)
Bluetooth	Bluetooth 4.0 with AudioB module
Working voltage	DC 10V-24V
Size	9.1cm x 5.0cm
Protection	Thermal and output current protection

Our Verdict

The TSA9840 amplifier board is a practical choice for makers and small-system builders who need compact, efficient stereo amplification with wireless connectivity. Its 20W per channel output, Bluetooth 4.0 integration and protection features make it good value for desktop speakers and compact home audio projects, though those seeking higher power or multi-input sources should consider more feature-rich modules.

Frequently Asked Questions

Does this board support Bluetooth streaming from phones?
Yes. The built-in Bluetooth 4.0 AudioB module allows wireless audio streaming from phones and tablets.

What power supply does it need?
It requires a DC supply in the 10V to 24V range; choose a supply that can deliver sufficient current for both channels at desired volume.

Is there protection against overheating or short circuits?
Yes. The board includes thermal protection and output current protection to reduce risk under heavy load or poor ventilation.