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Nobsound TA-21 Mini Bluetooth 5.0 DSP Amplifier with TPA3221 Review

A palm-size class-D amp on the TPA3221 chip, quoted at up to 100W per channel with Bluetooth 5.0 DSP, a 3.5mm AUX input and a digital volume display.

3.53.5 out of 5 starsUpdated October 14, 2026
$46.99Price checked October 14, 2026
Check price at Douk Audio
Nobsound TA-21 Mini Bluetooth 5.0 DSP Amplifier with TPA3221

Our verdict

The TA-21 is a tiny $46.99 class-D amplifier built around the TPA3221, which Douk Audio positions above the long-running TPA3116 for power and sound. Bluetooth 5.0 with DSP, a 3.5mm AUX input and a button-and-display volume control cover the basics, and it uses standard banana jacks for the speakers. The catch is the modest included 24V/3A supply: the listing says a larger one is needed for the quoted output, and Bluetooth is the only input that gets DSP.

Best for
Small desktop or bookshelf speaker setups that need a cheap, compact Bluetooth amp with a clean volume readout.
Skip if
You plan to use a bigger power supply for high output, or you want DSP processing on the wired input too.
Check price at Douk AudioHow we research

The Nobsound TA-21 is a mini integrated amplifier priced at $46.99 and sold as an updated version of the NS-20G from 2021, with claimed progress in output power, sound quality and heat generation. It is a class-D speaker amp built around the TPA3221 chip.

The listing quotes up to 100W per channel, enough to drive 3-inch to 10-inch speakers with 4-8Ω impedance, and says the amp runs cool even with floor-standing speakers attached. The frequency response is given as 80Hz-20kHz. Inputs are Bluetooth 5.0 with DSP processing and a 3.5mm AUX socket; the Bluetooth side is said to hold a stable connection out to about 50ft with low delay and no pops or audible noise. Note the small print: DSP only applies to the Bluetooth input, and AUX takes priority, so the cable has to come out to use Bluetooth.

Rather than a potentiometer, volume is set with buttons and shown on a display, with input indicators reporting the working state, a design the maker says avoids control noise. The amp is powered by DC 9V-24V at 3A or above with a minimum input power of 50W, and comes with a 24V power adapter; the listing warns that if the amp cuts out during use, the supply is too small and should be upgraded or the volume turned down. It measures 78 x 90 x 23mm and weighs 143g, with a black aluminium case and copper speaker terminals.

Douk Audio ships worldwide with free and expedited options at country-dependent prices. Packages under 2kg go by airmail in 10-25 days, and over 2kg by DHL, UPS or FedEx in 5-8 days; the TA-21 travels by airmail. Buyers are responsible for any import duties or customs charges. All items include a 30-day free return or full refund and a 1-year warranty, with exclusions for orders placed by mistake, man-made damage or misuse, a subjective change of mind, and anything else outside the warranty terms.

What we liked

  • TPA3221 chip that the listing places above the TPA3116 in power and performance
  • Button-based volume control with a display instead of a potentiometer, which the maker says avoids noise
  • Bluetooth 5.0 with DSP and up to roughly 50ft of wireless range
  • Said to run cool even when driving floor-standing speakers
  • Small 78 x 90 x 23mm aluminium case at 143g with crystal copper terminals

Worth noting

  • DSP processing applies to the Bluetooth input only, not the AUX input
  • The included 24V/3A adapter is the baseline; the listing itself says to use a bigger supply (minimum 50W input power) if you want higher output
  • The AUX input takes priority, so the cable has to be unplugged to listen via Bluetooth

Questions before you buy

How do I switch between AUX and Bluetooth?

The listing notes the AUX input takes priority: when an AUX cable is plugged in, the TA-21 defaults to AUX mode, so unplug it to use Bluetooth.

Will the included power supply deliver the full 100W per channel?

The 24V/3A adapter is described as enough for most home speakers. For higher output the listing says to prepare a larger power supply yourself (minimum input power 50W), and an outage during use means the supply is too small.

What speakers does it match?

3-inch to 10-inch speakers with 4-8Ω impedance, connected to banana speaker jacks.

What does the DSP actually apply to?

Bluetooth input only. The listing states explicitly that the AUX input does not get the DSP function.

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