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Green rectangular amplifier board with silver heatsinks, black knobs and blue Bluetooth antenna

ZK-TB21 2.1 Channel Bluetooth 5.0 Amplifier Board 50W+50W+100W

SKU CH-4RJ4-QWE8W

A 2.1-channel amplifier board delivering 50W per satellite and 100W to a subwoofer, with Bluetooth 5.0 and 3.5mm AUX inputs, dual TPA3116D2 chips, treble and bass controls, and protection circuits.

  • Sports Team1 Piece
  • 1 channel stereo output driven by dual TPA3116D2 chips
  • Bluetooth 5.0 wireless streaming up to 50 ft range
  • Independent treble and bass knobs for tone adjustment
  • Built-in over-voltage, under-voltage, over-heat and short-circuit protection
  • DC 12 V to 24 V wide input voltage for flexible power options

ZK-TB21 2.1 Channel Amplifier Board

The ZK-TB21 is a Bluetooth 5.0 amplifier board designed for DIY speaker builds. It uses dual TPA3116D2 chips to deliver 50W per stereo channel and 100W for a subwoofer. The board accepts DC input from 9V to 24V and includes treble and bass knobs for direct tone control. Builders wanting a compact, all-in-one 2.1 solution will find it suitable.

Practical Limits of Bluetooth 5.0 and Wired Input

Wireless streaming works up to 50 ft in open air, but walls and interference reduce that range. The board supports 4-8 ohm speakers and 50-300W rated drivers. Output power scales with supply voltage and drops as speaker impedance rises. AUX input only functions when no Bluetooth device is connected, so you must disconnect wireless pairing before using the 3.5mm jack.

Check Your Power Supply and Speaker Match

Verify that your DC source provides 12V to 24V and can supply current above the amplifier's actual draw. The onboard switch only puts the board into standby; full power-off requires unplugging the DC jack. Ensure your speakers fall within the 4-8 ohm range and 50-300W rating to avoid protection triggers or damage.

Highlights

  • 1 channel stereo output driven by dual TPA3116D2 chips
  • Bluetooth 5.0 wireless streaming up to 50 ft range
  • Independent treble and bass knobs for tone adjustment
  • Built-in over-voltage, under-voltage, over-heat and short-circuit protection
  • DC 12 V to 24 V wide input voltage for flexible power options

Specifications

Sports Team1 Piece

Questions about this item

Should I pick the 50W+50W+100W board or one of the higher-wattage versions?

Choose the 50W+50W+100W model when you need a 2.1-channel layout with a dedicated 100 W subwoofer channel and stereo satellites; the other versions are 2-channel or 4-channel designs with different power splits.

What does the 50W+50W+100W rating deliver in a finished speaker?

It provides up to 50 W per satellite and 100 W for the subwoofer when fed from a 12–24 V DC supply into 4–8 Ω loads, with actual output rising as supply voltage increases or speaker impedance drops.

How does Bluetooth 5.0 limit the audio chain on this board?

Bluetooth 5.0 handles the wireless link up to about 50 ft; the board then decodes to analogue for the dual TPA3116D2 chips, so the wireless hop is the only digital stage before amplification.

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