Nexum Aqua+ Review: APTx, Up-sampling, and Qi Charging, Oh My!

Nexum is a audio tech company based in Taiwan. They specialize in building high-quality source and wireless interconnect devices. Ranging from mobile DACs to WiFi adapters from your sound system, Nexum has quite the interesting lineup. Today we’ll be taking a look at their mobile Bluetooth DAC, the Aqua+.

You can find the Aqua+ available here for $150.


Build Quality

The Aqua+ is made from a brush-textured outer shell and plastic plates for the large faces. The assembly itself is quite well put together, but the plastic plates on the top and bottom have enough flex to be noticeable when you press on it a little. While its not in danger of breaking, it isn’t something I want to see from a $150 product. I’d like to see the plastic replaced with aluminum or at the very least reinforced for a more solid feeling. I understand that this may not be possible given the nature of wireless technologies, so instead glass would be a great substitute look-and-feel wise, if not a durable one.

Volume is controlled by a 32-step wheel located at the corner of the device. It is corrugated for additional grip. The wheel sits firmly in the frame and doesn’t jiggle around at all. It’s got a subtle, but satisfying, click feeling when turned and feels very precise while adjusting volume.

The side wall of the device houses an up-sampling toggle button and the headphone jack. The jack is well-placed within the frame and is lined with metal. It is the only port on the entire construction of the Aqua+.

On the bottom of the Aqua+ you’ll spot a curious lightning symbol. This symbol denotes the most unique and convenient feature of the Aqua+: its wireless charging. Compatible with all Qi charging pads, the Aqua+ is the only wireless DAC I’ve seen to make use to date. It works very well too, and the included wireless charging does its job flawlessly.


Nexum went with CS43130 for the DAC inside the Aqua+ CS43130; a low power chipset. It is capable of up-sampling Bluetooth’s native 16-bit depth to a 32-bit depth. While the perceptibility of improvements from going beyond 16-bit audio is still under debate, the fact that the Aqua+ offers the feature at all is a plus to many audiophiles. It uses Bluetooth 4.0 and supports aptX, aptX LL, AAC, and SBC audio codecs, one of the widest varieties I’ve seen at all.

Performance/Battery Life

Nexum claims that the Aqua+ can drive earphones and headphones up to 300 Ohms. While I haven’t been able to get my hands on anything quite that hard to drive, I found that the Aqua+ didn’t struggle to drive anything that I threw at it.

As far as sound signature goes, the Aqua+ didn’t have any coloring or tonal flavors to speak of. It was completely transparent, aside from the compression that it would naturally have from Bluetooth, though as per usual, that was near negligible too.

As far as battery life goes, at a medium volume, I averaged 6 hours and 31 minutes of use per day over the course of two weeks on reasonably efficient IEMs with my max use-time being 8 hours and 9 minutes and with the minimum being 5 hours and 44 minutes. Nexum lists the Aqua+ as having between 5–8 hours of battery life per charge, so these results are completely consistent with their claims.


Inside the box you’ll find:

  • 1x Nexum-branded Qi charging pad
  • 1x Micro-USB cable
  • 1x carrying clip

The charging pad and carrying case are made from a leathery material. I can’t tell if its genuine or a substitute, but I’m leaning towards the latter. The stitching on it is accurate and free from flaws. The carrying case fits the Aqua+ exceptionally well has a nice velvety interior to keep it from scratching. It’s easy to clip onto your pants and is not obtrusive.


The Nexum+ is one of the most advanced and convenient Bluetooth DAC’s I’ve seen to date. Featuring the latest in Bluetooth technology and support a slew of audio codecs, the Aqua+ is sure to work with all of your devices to provide you with a high-quality experience. It even features wireless charging, a blessing in today’s dongle-filled world. The Aqua+ isn’t perfect though. It is stylish and well designed but still feels a little flimsy. So if you’re willing to ignore the small amount of flex it gives you and want to hear what it has to offer, definitely check out the Aqua+. You get a ton of technology in a very tiny package.