Bluetooth Amplifier Board ZK-HT21 2.1 Channel 160Wx2+220W - Compact

In this review of the Bluetooth Amplifier Board ZK-HT21 the bottom line is simple: it is a compact, high-power 2.1 channel module aimed at hobbyists and DIY home speaker builders who want flexible inputs and serious bass. The reviewer found the board delivers clear stereo with a dedicated subwoofer channel and useful tone controls, making it a practical choice for someone assembling a bookshelf-plus-subwoofer system. Setup requires an appropriate DC 15-36V supply and basic wiring skills, but the sound and protection features justify the modest learning curve.

Key Features

• 2.1 Channel Output: Provides separate left/right channels plus a dedicated subwoofer channel so users can drive two passive speakers and a powered sub for fuller home audio.
• High Power Ratings: Delivers 160W per main channel and 220W to the subwoofer, enabling it to drive mid- to high-power speakers and produce strong low-end impact.
• TPA7498E Class D Chips: Uses two TPA7498E amplifier chips for low distortion and efficient operation across the audio band, helping achieve clear, high-definition sound.
• Multiple Inputs: Built-in Bluetooth 5.0 plus USB flash, USB sound card and 3.5mm AUX let users connect phones, flash drives or wired sources without extra hardware.
• Adjustable Tone and Subwoofer Control: Treble and bass controls, independent subwoofer volume and a 20-200Hz frequency knob let listeners tune the response to room and speaker choices.
• Protection and Cooling: Over-voltage, under-voltage, overheat and short-circuit protections along with a long-life silent fan provide reliability during extended use.

Who It's For

This amplifier board is best for DIY audio builders, hobbyists and anyone comfortable soldering or wiring who wants a compact, high-power 2.1 solution for home speakers. It fits projects where a single compact amp needs to power two full-range passive speakers and a dedicated subwoofer while offering tone shaping and modern inputs like Bluetooth 5.0.

It is less suitable for users who want a fully enclosed, plug-and-play hi-fi receiver with remote control and rack styling; likewise, those without a suitable DC power supply or basic electronics skills should look for a finished consumer amplifier instead.

Pros & Cons

Pros

• High output power for both main channels and subwoofer, producing impactful bass when paired with a capable sub.
• Bluetooth 5.0 and multiple inputs provide flexible source options for streaming and local playback.
• Tone controls and sub frequency adjustment allow precise tuning for room acoustics and speaker choice.
• Built-in protections and a silent cooling fan improve reliability in extended sessions.

Cons

• Requires an external DC 15-36V/8A (or higher) power supply and basic wiring; not a ready-made consumer unit.
• Board format may need an enclosure for permanent installations to meet aesthetic or safety preferences.

Specifications

Channels	2.1 (left, right, subwoofer)
Power Output	160W x2 + 220W subwoofer
Amplifier Chips	TPA7498E class D
Inputs	Bluetooth 5.0, USB flash, USB sound card, 3.5mm AUX
Supply Voltage	DC 15-36V (recommended supply >=8A)
Subwoofer Frequency	Adjustable 20-200Hz
Protection	Over-voltage, under-voltage, overheat, short-circuit

Our Verdict

The ZK-HT21 Bluetooth Amplifier Board is a strong value for DIYers who need a compact, high-power 2.1 module with modern inputs and tone controls. It excels when paired with capable passive speakers and a subwoofer and rewards users who can provide an appropriate DC supply and enclosure; the combination of TPA7498E chips, sub control and protection features makes it a practical, tunable foundation for home audio projects.

Frequently Asked Questions

What power supply does this board require?
Use a DC 15-36V supply rated at 8A or higher; higher voltage/current will increase available output but ensure the supply exceeds the amplifier's working power.

Can it drive two passive speakers and a subwoofer?
Yes, it is a 2.1 channel module designed to drive two passive speakers (4-8 ohms, 30-200W) plus a subwoofer (30-220W).

Does it support Bluetooth streaming?
Yes, the module includes Bluetooth 5.0 for faster transmission and improved decoding with a range up to about 15m (49ft) in open space.