Nobsound TA-21 Bluetooth DSP Amplifier 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.
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.
Why 3.5/5: The page gives chip, speaker match, input range, size and weight for $46.99. Held back by a packing list that names no power supply, an 80Hz low end with no tolerance, claims of beating the TPA3116 with nothing behind them, and no THD or SNR figures.
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.
Specifications
| Spec | Page says |
|---|---|
| Brand and model | Nobsound TA-21 |
| Audio input | 3.5mm AUX / Bluetooth |
| Audio output | Banana speaker jacks |
| Bluetooth version | 5.0 |
| Max output power | 100W+100W |
| Amp IC chip | TPA3221 |
| Matched speaker | 3''-10'' / 4-8Ω |
| Frequency response | 80Hz-20KHz |
| Working voltage | DC 9V-24V / 3A or above |
| Minimum input power | 50W |
| Dimensions (W*D*H) | 78*90*23mm / 3.07*3.54*0.91in |
| Net weight | 143g / 0.32lb |
| Package weight | 600g / 1.32lb |
| Packing list | TA-21 amplifier ×1, user manual ×1 |
| Bluetooth range (feature text) | Up to 50ft |
| Volume (feature text) | Buttons rather than a potentiometer, with a volume display and input indicators |
How it compares
The TA-21 is the priciest of the three TPA3221 mini amps compared here and the only one whose packing list names no power supply. The Nobsound NS-01G MAX Amplifier 100W+100W review ($39.99, $7.00 less) has the same chip, the same 78mm width and 23mm height and a 19V adapter on its packing list, adds a PRE OUT, and is 70mm deep against 90mm. The Nobsound Q10 Bluetooth Amplifier 100W review ($36.99 is its Without Power Supply option, $10.00 less; With Power Supply is $47.99) adds an optical input and lists 20Hz-20kHz (±3dB) where the TA-21 lists 80Hz-20KHz with no tolerance.
What the TA-21 adds, per its page, is DSP on the Bluetooth link, buttons rather than a potentiometer for volume and a 3-10 inch, 4-8 ohm speaker match (the Q10 page also lists a volume display); the page gives no THD or SNR. It suits a desk with a PC or phone over Bluetooth and, going by the packing list, your own 9V-24V supply of 3A or more; skip it if you want an adapter confirmed in the box, an optical input or a pre-out. The Nobsound NS-20G Bluetooth Headphone Amp 100W+100W review shares the 78 x 90 x 23mm footprint and swaps the TPA3221 for two TPA3116 chips, with a 3.5mm headphone output added.
Shipping, returns and warranty
- Shipping: Douk Audio's current shipping page says orders are generally processed no later than the next business day and arrive in 2-8 business days, with duties, taxes and customs fees included in the checkout price unless noted otherwise.
- Older shipping terms are still online: airmail at 10-25 days for parcels under 2 kg, DHL, UPS or FedEx at 5-8 days above that, and a line saying the store is not responsible for import duties. Check the delivery estimate and any duties at checkout.
- Returns: ask within 30 days of delivery and wait for approval before sending anything; an approved return has to ship within 7 days. Items need all packaging and accessories and no excessive wear, or the store can refuse them or refund part of the price. Refunds go to the original payment method after inspection.
- Not refunded: original and expedited shipping, duties, taxes and customs charges, unless the law requires it or the store made the error. The return page does not say who pays return postage, and the older refund page excludes mistaken orders and change-of-mind returns from free after-sale service.
- Warranty: 24 months from purchase for manufacturing defects, with free repair, a replacement unit and free shipping both ways for covered repairs. Drops, liquid, DIY repairs, lightning, extreme temperatures and misuse are excluded (partial fees may apply), and damage from weak packing on the way back may not be covered. The older refund page still says 1 year.
- Seller: the site is run by Shenzhen Anba Technology Co., Ltd (Shenzhen, China) and HONGKONG LONGSHENG Import and Export Trading Co., Limited (Hong Kong); support is by email at [email protected]. These terms cover orders placed on doukaudio.com; other sellers apply their own.
For this product, the page lists US, UK, EU, AU and Other under 'Shipping to' and shows Free Shipping, 2-8 Days Arrival, 30-Day Return and 2-Year Warranty badges near the price.
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.
Sources & verification
What this review is based on and the day we last read it. Specs and claims from the maker are the maker’s own; the verdict and the rating are ours.
From the store
- Douk Audio product pagePrice $46.99, features, parameters (chip, speaker match, 9-24V input, minimum input power, size, weights) and the packing list (amplifier and manual).Read October 25, 2026
- Douk Audio shipping policyOrders are generally processed no later than the next business day, 2-8 business days in transit, duties, taxes and customs fees included at checkout unless notedRead October 25, 2026
- Douk Audio older shipping policyOlder terms still online: airmail 10-25 days under 2 kg, DHL/UPS/FedEx 5-8 days above, store not responsible for import dutiesRead October 25, 2026
- Douk Audio return and refund policy30 days from delivery with prior approval, ship back within 7 days; shipping, duties and taxes not refunded unless the store erredRead October 25, 2026
- Douk Audio older refund policyOlder terms still online: 30-day free return or refund and a 1-year warranty; mistaken orders and change of mind are excludedRead October 25, 2026
- Douk Audio 24-month warranty page24 months from purchase for manufacturing defects: free repair, replacement unit and two-way shipping for covered repairs; lists exclusionsRead October 25, 2026
- Douk Audio contact pageSite run by Shenzhen Anba Technology Co., Ltd and HONGKONG LONGSHENG Import and Export Trading Co., Limited; support emailRead October 25, 2026
What we couldn’t verify
- The supply is unclear: the store's warm tip says the amp is 'default equipped with 24V/3A power supply' (what the review said), but the packing list shows only the amplifier and a user manual. Check what the order includes before paying.
- The review's notes that AUX takes priority, that DSP applies to Bluetooth only, and that the amp is an updated NS-20G from 2021 come from the store's product description; they are not in the page text read on Oct 25, 2026.
- The page quotes 100W+100W, a supply of 3A or above and a minimum input power of 50W, but no load, voltage or distortion figure for the rating and no output figure for any supply.
- 'Much better than TPA3116 in power and performance' and 'ultra-low heat emitting' are page claims with no measurement or comparison behind them.
- The frequency response, 80Hz-20KHz, has no tolerance, and the page lists no THD or SNR.
- 'Up to 50ft' of Bluetooth range and 'no pop and no audible noise' have no test conditions, and no codec is listed.
Spotted an error or something out of date? Tell us and we’ll fix it and update the date.
Nobsound NS-10G PRO Bluetooth Amplifier DSP — read reviewNobsound NS-10G PRO Bluetooth Amplifier DSP
An upgraded mini amp built around a TPA3221 chip rated at 100W x 2, with Bluetooth 5.0 + EDR + DSP reaching 15m, a deliberately volume-knob-free circuit path, and gold-plated binding posts.
Nobsound NS-01G PRO Amplifier 50W x 2 — read reviewNobsound NS-01G PRO Amplifier 50W x 2
A 50W x 2 mini amplifier on the TPA3116 chip with Bluetooth 5.0, USB and 3.5mm AUX inputs, sold in five colours with or without a power supply.
Nobsound TONE Mini Bluetooth Stereo Amplifier — read reviewNobsound TONE Mini Bluetooth Stereo Amplifier
A 50W x 2 mini power amp using the TPA3116 chip with Bluetooth and AUX inputs, an infinite-rotation encoder knob and a compact aluminum build with a DC 19V adapter included.