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Nobsound DA7 HiFi Vacuum Tube Power Amplifier with Bluetooth, RCA and USB Inputs Review

A pure tube power amplifier with four 6P1 output tubes and three 6N1 driver tubes, rated 12W x 2 into 4 ohms, with Bluetooth 5.3, USB 3.0, dual RCA inputs and twin analog VU meters.

3.83.8 out of 5 starsUpdated October 14, 2026
$349.99Price checked October 14, 2026
Check price at Douk Audio
Nobsound DA7 HiFi Vacuum Tube Power Amplifier with Bluetooth, RCA and USB Inputs

Our verdict

The Nobsound DA7 is a proper tube amplifier at $349.99: four 6P1 output tubes and three 6N1 driver tubes, an imported wideband EI transformer and twin analog VU meters, with Bluetooth 5.3, USB 3.0 and dual RCA inputs so modern sources can feed it too. Output is 12W x 2 into 4 ohms, so pair it with efficient speakers in a normal room. Check mains voltage — the spec sheet lists AC 220V — and give those seven glowing tubes room to breathe.

Best for
Listeners who want genuine tube amplification with modern inputs — Bluetooth, USB files and RCA — paired with efficient speakers in a small or medium room
Skip if
Your speakers are low-efficiency or the room is large, or you are on 110-120V mains and cannot confirm the correct voltage version
Check price at Douk AudioHow we research

The Nobsound DA7 is a vacuum tube power amplifier priced at $349.99. It uses an authentic pure tube topology — 4x 6P1 tubes in the power amplification stage and 3x 6N1 for voltage amplification and driver stages — for warm, natural sound with an expansive dynamic range.

It is rated at 12W x 2 into 4 ohms and 8W x 2 into 8 ohms, with a frequency response of 10Hz-40kHz (-3dB), THD of 1% at 1kHz, SNR of 85dB and a 100K ohm input impedance. The output stage uses an imported wideband EI output transformer, and the signal path is finished with gold-plated pure copper connectors. A steel mesh protective cover keeps the tubes safe while ensuring efficient heat dissipation.

Inputs cover modern and traditional sources alike: dual RCA jacks, a USB port supporting USB 3.0 high-speed audio transmission and U-disk file playback up to 128GB (FAT32/ExFAT, with MP3, WMA, APE, FLAC, AAC and WAV files), and dual-mode Bluetooth 5.3/5.0 for fast pairing and stable wireless audio. A dedicated input switch knob makes source selection seamless. On the front, two analog VU meters respond dynamically to the power amplification signal, adding classic needle movement and real-time monitoring.

Two practical points: with 12W per channel, the DA7 is best matched to reasonably efficient speakers in a small or medium room, and the published spec sheet lists AC 220V input, so confirm the correct mains version for your region before ordering. At 7.6kg net weight with seven tubes, it also needs a sturdy, ventilated shelf with clearance for heat.

Shipping is worldwide with free and expedited options, and cost varies by country. At 7.6kg this amplifier ships by DHL, UPS or FedEx in an estimated 5-8 days. Import duties and customs fees are the customer's responsibility. Free 30-day returns with a full refund and a 1-year warranty apply to all items, excluding orders placed by mistake, man-made damage or misuse, subjective change of mind, and anything else outside the warranty terms.

What we liked

  • A genuine pure tube design — 4x 6P1 power tubes and 3x 6N1 driver tubes deliver warm, natural sound with an expansive dynamic range
  • Broad input set for a tube amp: dual RCA, USB 3.0 high-speed playback (including U-disk files up to 128GB) and dual-mode Bluetooth 5.3/5.0
  • Twin analog VU meters respond to the power-amplification signal for real-time monitoring with classic needle movement
  • Imported wideband EI output transformer, gold-plated pure copper connectors and a steel mesh cover that protects the tubes while aiding heat dissipation
  • Wide 10Hz-40kHz (-3dB) frequency response and a generous 100K ohm input impedance

Worth noting

  • At 12W x 2 into 4 ohms, it needs reasonably efficient speakers and suits small to medium rooms rather than power-hungry designs
  • The spec sheet lists AC 220V input, so buyers outside 220-240V regions should confirm the mains version before ordering
  • Seven hot tubes and a 7.6kg chassis demand a sturdy, well-ventilated shelf and care around children and pets

Questions before you buy

How much power does the DA7 produce?

It is rated 12W x 2 into 4 ohms and 8W x 2 into 8 ohms, with 150W total power consumption, from a pure tube design using 4x 6P1 power tubes and 3x 6N1 driver tubes.

What can I connect to it?

Dual RCA inputs, a USB port (USB 3.0, including U-disk playback up to 128GB in FAT32/ExFAT with MP3/WMA/APE/FLAC/AAC/WAV support) and dual-mode Bluetooth 5.3/5.0. Outputs are banana speaker jacks and a stereo RCA output.

What voltage does it require?

The published specification lists AC 220V input. Buyers outside 220-240V regions should confirm the correct mains version before ordering.

What are the shipping and warranty terms?

Worldwide shipping with free and expedited options; at around 7.6kg this amp ships by DHL/UPS/FedEx in about 5-8 days. Import duties are the customer's responsibility. Free 30-day returns for a full refund and a 1-year warranty apply, excluding orders by mistake, misuse, change of mind and anything outside the warranty terms.

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