Nobsound NS-02E Vacuum Tube Headphone Amplifier Review

Looking for a headphone amplifier? How about a tube-equipped preamp? The Nobsound NS-02E amp doubles as both all while fitting within the palm of your hand. The NS-02E can be paired with your preamp, smartphone, computer, iPod, stereo system, or any other audio device you want to plugin. Add your favorite headphones into the mix and you will get to listen to soft, warm, and exceptionally clear music all day long.

This amp features perfect plug-and-play operation with high-quality 6N3 tubes provided as the default setup. While it’s by no means necessary, you can swap these out for  6A8Q, 2C51, 5670, 5185, 6385, 6185, WE396, ECC 42, 6H3N, 6H3II, ECF82, or 6CC42. Best of all, this little amp is affordable, and Hi-Fi newbies and veterans alike will enjoy it.


Beautiful Design With Excellent Functionality

Design matters, and Douk Audio has paid close attention to the overall appearance and build quality of this little amp. Aside from being handheld and super compact, Douk Audio has gone the extra mile to ensure that the finished product is durable and able to last a lifetime of playing. That’s why it features an anodized aluminum chassis along with a replaceable tube up top that illuminates a bright blue when powered on.

They also have made sure that all of the function is there, which is why this has become many audiophiles’ first choice for powering their high-performance headphones or active speaker system. As a dual-purpose amp, you can also plug in the NS-02E as a pre-amp to your power amplifier to upgrade its dynamics and musicality.

Superb Sound Quality

There’s no doubt that the built-in tubes it comes with provides excellent sound quality, with many reviewers noting that, after trying it out, they chose not to swap the tubes out as they had originally intended to. While you most certainly can give this unit an upgrade to make it sound even better for your setup, the tubes it comes with are perfectly functional without a second thought.

This preamp as a whole is able to produce the sound you’re after with a “rich bottom end and a smooth and creamy mid-range.” There is absolutely no reason to substitute the tubes for most players, unless you have a very specific setup you’re after or you just like fiddling around.


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  • Anodized aluminum chassis that is durable and meant to last.
  • Compact and can fit within the palm of your hand!
  • Designed to look great and sound even better.
  • Pair it with your favorite headphones along with your preamp, smartphone, computer, iPod, stereo system, and countless other audio devices.
  • Comes with the classic 6N3 tube as the default, which makes it functional right out-of-the-box yet easy to “upgrade” if you so choose.
  • Affordable for both newbies and Hi-Fi veterans.


Customer Reviews

This preamp may be compact, but that in no way reflects the sound quality it is capable of producing. “The sound is amazing out of this little guy.” You can drive the volume up pretty high and the output will remain clear and warm, proving that you don’t have to toss hundreds of dollars into getting a high-quality headphone preamp.

The only critical review this product has gotten has been a result of user error: “ bought this and some expensive headphones. The preamp seemed to work until it made very loud cracking sounds which instantly blew my new headphones.”

As respondents to this reviewer clarified, this preamp needs to be used correctly. “You’re only supposed to use headphone amps with a signal that isn’t already pre amplified, such as passive audio output from a television or HiFi head unit of some kind.”

So, if you use this little amp as it is intended to be used (i.e., do your research!) you won’t run into any problems with it. With that being said, I have absolutely no hesitancy when suggesting it for someone who’s in the market for such a compact and highly functional headphone amplifier.

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