Nobsound DA3 Bluetooth Tube Amplifier Review

The Nobsound DA3 is an integrated tube amplifier priced at $189.99. It combines a tube preamp stage with solid-state power amplification: two Beijing 6J1 tubes shape the signal ahead of an output stage rated at 35W x 2 into 4 ohms and 25W x 2 into 8 ohms, driving speakers through banana jacks.

Connectivity is the DA3's strongest suit. Alongside standard RCA inputs and speaker outputs it offers Bluetooth, USB lossless playback from a U-disk (up to 128GB, supporting FLAC, APE, MP2, MP3, WMA, AAC, MP4, M4A and WAV), optical and coaxial digital inputs, a PRE OUT for active subwoofers and a 3.5mm headphone output. Dual RCA inputs make it easy to connect and compare two sources, and a dedicated input switch with indicator light keeps operation simple.

The tube design is credited with a rich, smooth and warm character and a subtle harmonic richness that makes vocals sound natural and detailed. Independent treble and bass adjustments let you tailor the balance by genre. The power supply is built around a 90W transformer and four 2200uF 35V electrolytic capacitors for clean, stable delivery, in a chassis measuring 170x259x147mm and weighing about 3kg.

The published specifications are honest about the design's priorities: frequency response of 60Hz-20kHz (±3dB), SNR of 70dB, THD of 1% and RCA input sensitivity of 500mV. That profile suits listeners chasing tube warmth rather than ruler-flat neutrality. Note also that the spec sheet lists AC 110V/220V input, so check which mains version you are ordering for your country.

Specifications

How it compares

The ST-01 PRO Bluetooth Tube Amplifier review ($109.99, $80.00 less) offers a higher rating and wider digital support on paper: 100W+100W into 4Ω, Bluetooth 5.0, PC-USB, coaxial, optical, RCA and U-disk inputs, and printed THD of 0.07% and SNR of 98dB or better, against the DA3's 35W x 2, THD of 1% and SNR of 70dB. The DA3 page offers what the ST-01 PRO page does not: a 3.5mm headphone jack, a stereo RCA pre-out (the ST-01 PRO has a 3.5mm AUX output), two RCA inputs, a 128G U-disk limit (64G on the ST-01 PRO page) and a different tube set (two 6J1 tubes in the preamp stage, against GE 4BZ6 on the ST-01 PRO page text and 6K4 in its description). The DA3 lists AC 110V / 220V input, while the ST-01 PRO takes DC 18-30V from a 24V adapter in the box; the DA3's packing list shows only an amplifier and an antenna, so check how the power cord is supplied.

Above it, the Nobsound DA7 Vacuum Tube Power Amplifier review ($349.99 for US, UK and EU destinations, $160.00 more) is a pure tube amplifier: 12W x 2 into 4Ω and 8W x 2 into 8Ω, with Bluetooth 5.3/5.0, USB and RCA inputs, twin VU meters and a 7.6kg chassis against the DA3's 3kg. The DA3 page lists higher power into the same loads (35W x 2 into 4Ω, 25W x 2 into 8Ω) with two 6J1 tubes in the preamp stage, plus optical and coaxial inputs and a headphone jack. The Nobsound AV-525 Bluetooth Vacuum Tube Amplifier review ($459.99, $270.00 more) adds VU meters and 100W+100W into 4Ω, with THD of 0.1% and SNR of 88dB or better, and a dedicated subwoofer output where the DA3 has a pre-out. Choose the DA3 for a mid-priced hybrid with a headphone jack and a wide input list; choose the DA7 for tubes in the power stage; choose the AV-525 for the highest printed power and the best printed SNR and THD of the three.

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 has a 'Shipping to' selector (US, UK, EU, AU, Other) and shows Free Shipping, 2-8 Days Arrival, 30-Day Return and 2-Year Warranty badges near the price.