ZK-TB21 Bluetooth Amplifier Board 2.1 Channel - Powerful 50W+50W+100W

In this review of the ZK-TB21 Bluetooth Amplifier Board, the bottom line is simple: this is a compact, high-power Class D amp module for DIYers and builders who need clear stereo and a punchy sub output. Its single biggest reason to buy is the dual TPA3116D2 chip design delivering 50W per stereo channel plus 100W for a subwoofer, which provides sustained high-power output with low distortion for small home theater setups or outdoor speakers. The reviewer found Bluetooth 5.0 connectivity and onboard treble and bass controls make it convenient for both wired and wireless sources.

Key Features

• Dual TPA3116D2 chip: ensures continuous high-power operation and low distortion for clearer midrange and highs during loud playback.
• 2.1 channel output: 50W per left and right plus 100W sub output delivers real low-end impact for compact subwoofers and home theater use.
• Bluetooth 5.0 and AUX input: fast, reliable wireless pairing with up to about 50 ft range in open spaces and a 3.5mm AUX fallback for non-Bluetooth sources.
• Treble and bass control knobs: let you tailor high and low frequency response on the fly to suit music, movies, or live playback without needing an external EQ.
• Wide voltage and protections: runs from DC 12V to 24V and includes overheat, reverse, over-voltage and under-voltage protection for safer continuous use.
• Included accessories: comes with a protective shell, DC plug set, knob, screwdriver and five large heat sinks to support sustained power output.

Who It's For

The ZK-TB21 is aimed at hobbyists, small home theater builders and outdoor audio enthusiasts who want a compact amplifier board that delivers significant power without needing a bulky receiver. It is particularly well suited for people who want an easy Bluetooth source plus the option to fine-tune treble and bass from the amp itself.

Those who should look elsewhere include buyers wanting a fully assembled commercial receiver with remote control or advanced digital inputs; this board is a module intended for integration and DIY installation rather than a finished consumer stereo component.

Pros & Cons

Pros

• High continuous output with dual TPA3116D2 chips gives clean, loud playback and a strong sub channel.
• Bluetooth 5.0 pairing is quick and stable, and AUX input works when Bluetooth is disconnected.
• Onboard treble and bass controls and included heat sinks improve usability and thermal performance during extended use.

Cons

• As a board module, it requires some assembly and installation effort, so it is not a plug-and-play consumer receiver.
• Size is compact, which some users noted; thermal management relies on correct mounting of the supplied heat sinks.

Specifications

Our Verdict

The ZK-TB21 amplifier board is a practical, value-oriented choice for DIYers and small system builders who need a compact Class D amp with strong sub output and flexible inputs. With reliable Bluetooth 5.0, useful treble and bass controls, and built-in protections, it delivers excellent performance for the price provided you are comfortable fitting a module into your enclosure.

Frequently Asked Questions

Can I use Bluetooth and AUX at the same time?
Bluetooth takes priority when both are connected; to use AUX, disconnect the Bluetooth connection first.

What voltage do I need to run this board?
It runs from DC 12V to 24V; choose a stable supply in that range sized to handle peak power demands.

Does it include cooling accessories?
Yes, the package includes five 502510mm large heat sinks and a protective shell to help with heat dissipation.