ZK-TB21 Power Amplifier Board Bluetooth 5.1 TPA3116 - 2.1 Channel

Our review of the ZK-TB21 finds it best suited for DIY audio builders and small home theater projects who need a compact, highpower 2.1 amplification solution. The single biggest reason to consider it is the use of dual TPA3116D2 chips, which deliver clean stereo output and a dedicated subwoofer channel while keeping distortion low during extended use. Connection options include Bluetooth 5.1 and a 3.5mm AUX jack, and the board includes practical protection features that make it reliable for continuous operation.

Key Features

• Dual TPA3116D2 chips: Provides stereo plus subwoofer channels with sustained high power and low THD for clear playback at louder volumes.
• 2.1 channel output: Delivers a combined peak arrangement of 50W + 50W + 100W, suitable for bookshelf speakers plus a powered subwoofer.
• Bluetooth 5.1 and AUX inputs: Lets users stream wirelessly from phones or connect TVs and laptops via the 3.5mm jack for flexible source options.
• IPEX antenna interface: The firstgeneration U.FL/IPEX socket allows an external antenna to be added for more stable Bluetooth range.
• Comprehensive protection: Builtin shortcircuit, overcurrent, overheat and antireverse protections help protect connected components and the board itself.
• Wide DC input: Supports DC 12-24V, making it compatible with a variety of power supplies used in DIY and compact audio systems.

Who It's For

The ZK-TB21 is ideal for hobbyists assembling compact home audio systems, makers integrating an amplifier into small home theater cabinets, and anyone who wants a straightforward Bluetooth plus AUX 2.1 amplifier with protection circuitry. It is especially useful when space is limited but a dedicated subwoofer channel is desired.

It is less appropriate for professional studio mastering or very highend audiophile setups where component selection and ultralow noise floor are critical. Buyers who need bundled speakers, an external antenna included, or an integrated enclosure should look elsewhere and be prepared to source those items separately.

Pros & Cons

Pros

• Clean, sustained power from TPA3116D2 chips for reliable stereo and subwoofer performance.
• Convenient Bluetooth 5.1 streaming plus 3.5mm AUX for versatile connections.
• Protection features and wide DC input make it safe and flexible for DIY installations.

Cons

• External Bluetooth antenna is supported but not included, so range improvements require an extra purchase.
• No enclosure or speakers provided, which requires additional components for a finished system.

Specifications

Configuration	2.1 channel (stereo + subwoofer)
Amplifier chips	Dual TPA3116D2
Power output (peak)	50W + 50W + 100W
Inputs	Bluetooth 5.1 and 3.5mm AUX
Bluetooth antenna	1st generation IPEX (U.FL) interface, antenna not included
Protection	Shortcircuit, overcurrent, overheat, antireverse
DC input	DC 12-24V

Our Verdict

The ZK-TB21 is a practical, valueoriented 2.1 amplifier board for DIY and compact home theater builds; its TPA3116D2 dualchip design and safety features deliver dependable, lowdistortion sound for most consumer use cases. Pick this board if you plan to assemble your own speakers or integrate an amp into an enclosure and want Bluetooth streaming plus robust protection without paying for excess features.

Frequently Asked Questions

Does this board support external Bluetooth antennas?
Yes. It uses a 1st generation IPEX (U.FL) interface so you can attach an external 2.4 GHz antenna for improved range; the antenna is not included.

What power supply is required?
The board accepts a DC input between 12V and 24V; choose a supply that can provide sufficient current for your speaker loads.

Is it safe to run continuously?
The amplifier includes shortcircuit, overcurrent, overheat and antireverse protections designed to support long operational periods.