Nobsound NS-03G SUB 100W Mono Subwoofer Amplifier Review

The Nobsound NS-03G SUB is a mono subwoofer amplifier priced at $36.99. It is the latest updated version of the model, with a simplified circuit, upgraded components and claimed improvements in sound quality.

The amplifier uses a classic TPA3116D2 class-D chip, with a maximum output power of 100W into a 4Ω load, and the maker says it easily drives most passive subwoofers. The TL072 op amp is chosen for ultra-low distortion and dynamic balance, and the quoted figures are THD of 0.01% or less and an SNR of at least 118dB, with input sensitivity of 280mV or below. The frequency range is listed as 20Hz-180Hz, which places it squarely in subwoofer duty.

A single 3.5mm AUX input is provided, and because there is a built-in preamplification circuit, sources with low signal output such as phones, TVs, MP3 players, CD players, computers and amplifiers with a low-frequency output can all feed it. Speaker connection is through banana jacks, and the matched subwoofer impedance is 4-8Ω. The amplifier measures 69 x 88 x 33mm and weighs 190g, with a black aluminium alloy case, and the design includes protection circuitry described as spark-free and shock-free. The listing offers the amplifier either alone or with a 19V/4.74A power supply, so check which version you are buying.

Specifications

How it compares

At $36.99 (the option without a power adapter) the NS-03G ties with the Nobsound G2 Mini as the cheapest amplifier in this group, but they offer different things. The NS-03G is a subwoofer-only design: 20Hz-180Hz, 100W into 4Ω, a single 3.5mm input with a built-in preamplification stage and one volume knob. The G2 Mini adds a subwoofer/full-frequency switch, a four-step gain switch and a 40-300Hz cutoff, at a listed THD of 0.03% at 1W and SNR of at least 106dB, against the NS-03G's THD of 0.01% or less and SNR of at least 118dB (the NS-03G page gives no conditions for its figures). The Nobsound NS-21G costs $39.99, which is $3.00 more, and includes a DC 19V adapter in the box, with RCA and 3.5mm AUX inputs and a bass cutoff listed as 20-160Hz.

Who it suits: the NS-03G fits a small bookshelf or desktop system with a passive subwoofer, where a 3.5mm source and a plain volume knob are enough. Skip it if you need RCA inputs, a cutoff control or stereo: the page lists none. The 19V/4.74A supply is a separate option: the With Power Adapter version costs $46.99, which is $10.00 more, and the page opens on that version. The Douk Audio G4 at $44.99 ($8.00 more than the NS-03G, also without an adapter) adds a mode switch for full-frequency use and an RCA input.

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 shipping to US, UK, EU, AU and Other and shows Free Shipping, 2-8 Days Arrival, 30-Day Return and 2-Year Warranty badges near the price.