Review: Nobsound Bluetooth HiFi 6J1 Vacuum Tube Preamplifier


The versatile Nobsound Bluetooth HiFi 6J1 Vacuum Tube Preamplifier features 6J1 vacuum tubes and a preamp equipped with Bluetooth (along with RCA and 3.5mm stereo options). You’ll enjoy the multiple input options, including: CD, phone, lossless player, or even your computer. Plus, what I really loved about this particular preamp is how warm and broad of a sound you can get by adjusting the treble and bass to your liking.

There is no background noise, which is a huge and obvious plus, and the input/output terminals are gold-plated to ensure high-quality sound. Above all, this preamp is the perfect size for my small playing area since it’s smaller than average. Trust me though, they haven’t compromised on the sound!

Built To Last

This preamp was clearly made with the player in mind, and Douk Audio intends for it to be a part of your setup for the long-term. This is demonstrated by the excellent build quality that you’ll notice from the second you lift it out of the box. It feels solid and nicely constructed, and this quality is also clearly projected when you plug it in for the first time and begin using it.

This is a truly high fidelity unit, even if you have to use longer cable runs because of your setup. Thanks to the carefully designed internal components, you will experience little to no added noise with the use of this preamp.

Out-of-the-box Functionality

One feature that really deserves highlighting about this preamp is that, straight out-of-the-box, you can expect it to improve your sound quality significantly. It will instantly make the sound of your setup seem clearer and more full, and some slight adjustments for the treble and bass should get everything to your liking.


  • Features a convenient Bluetooth setting so you can stream from your phone or other device over WiFi
  • Use the 3.5mm stereo input or RCA to plug your audio source in directly.
  • Switch between your different audio sources with ease.
  • Connect to both digital amplifiers and active multimedia audio devices in a snap.
  • Adjust the treble and bass with the twist of a knob.
  • Adds a warmth and depth to your sound.
  • Gold-plated input/output terminals for silence and sound quality.
  • Minimal background noise even with long cable runs.
  • Features 6J1 valve tubes, and this preamp comes with a spare!
  • Compact size that is perfectly suitable for a desktop or smaller setup.

Customer Reviews

One thing to note is that this system, out-of-the-box, will instantly improve any setup you have going. “It definitely warms up and broadens the sound of anything streaming.” You should also note that a few adjustments to the bass and treble knobs will instantly get you a sound that matches your personal tastes.  

“Bluetooth range is limited to the immediate next room…” which is something you should keep in mind if you intend to be using the Bluetooth streaming feature a lot. Another reviewer posted that the sound quality of Bluetooth isn’t quite as smooth as the direct inputs.

However, the output quality of any Bluetooth stream is going to depend on the strength of the signal the preamp is able to get. This means, if you keep your Bluetooth source nearby, you shouldn’t experience any issues with it, as a couple other reviewers can attest: “…for streaming I now use the Bluetooth on this unit and it works great.”

All of this makes me confident to recommend the Nobsound Bluetooth HiFi 6J1 Vacuum Tube Preamplifier to anyone who is in search of a quality but compact preamp to add to their setup. This one is worth picking up if you like the versatility of the added input options and the low noise operation.

I for one take versatility as a top priority, and this preamp offers it. Most of my streaming is done via Bluetooth or directly with a 3.5mm jack, so this preamp is perfect for my needs. Its smaller size is also a huge plus, because very few of us have unlimited space to store all of our “toys” (after all, tube amps take up a lot of space). I have no issues with the overall design of the product, and I would suggest it to anyone on the lookout for a compact, high-quality preamp to add to their setup.