Features
There is a lot to unpack here, but what I’m going to do is discuss its features in detail, alongside my surmised footnotes, both positives and negatives, as we progress through the review.
File format compatibility
The xDuoo XA-02 supports MQA, DSD256, PCM, and DXD. I use YT music (256Kbps AAC) as my source of truth. However, universal file compatibility is always a welcomed feature.
Digital volume controls and OLED display
The XA-02’s digital volume control, paired with a high-visibility and well-lit OLED display, allows for seamless navigation between different sub-menus and input options.
The XA-02’s digital volume knob operates a button, volume control and navigation tool. It’s a very intuitive and sensible experience that’s difficult to critique.
Moreover, the volume control’s recessed ridges enhance its ease-of-grip, boasting a friction-free rotation.
Headphone out protections
To avoid ‘pops’ and ‘clicks’, the XA02 has in-built protections to avoid damage to your precious headphones or earphones when plugging them in or when turning the XA-02 off.
As a paranoid audiophile, this is an excellent feature that inspires confidence in the reliability of the XA-02 as the Swiss-army-knife of amplifiers.
Multiple inputs
As discussed earlier, this set offers a plethora of input options for excellent versatility. Switching between notes can be done by pushing the volume pot down and selecting the desired input.
Unfortunately, I could not review the optical and coaxial inputs due to the lack of peripherals to test them with.
USB-C
There are no driver installations – it is a strictly plug-and-play unit with virtually no compatibility issues with my Dell laptop or Nothing Phone 2(A).
Bluetooth
The Bluetooth feature is only available once you’ve installed the included antenna. xDuoo offers support for aptX, LDAC, and AAC codecs, so expect full-on compatibility with Android and Apple smart devices.
Searching for the xDuoo XA-02 for connection is an effortless endeavour that took mere minutes to set up.
Using my Nothing 2(A) and YT Music as my musical source of truth (256Kbps AAC), the XA-02 offers a fairly stable and reliable connection with little to no discernible signal interference or dropouts (albeit occasionally).
I would’ve found this feature more useful if the XA-02 came with a speaker out, offering users the ability to convert their laptop setup into a wireless audio speaker system.
ESS ES9039Q2M DAC
The xDuoo XA-02 generously incorporates a top-of-the-line ESS DAC, complemented further by high-end capacitors and professional power management chips. On paper, this is a high-performing set. But we’ll discuss the intangibles in a later section.
Fully-balanced output
The XA-02’s balanced design starts from its decoding stage through its amplifier circuit. The independence of each signal path majorly curbs the possibility of signal interference and inter-channel crosstalk, promising 2000 mW of power through its 4.4mm balanced output.
Accomplishing a true balanced output with a rated output of 2000mW is a serious feat, given its accessible price range. I don’t have many IEMs or headphones with a power-hungry impedance, but the majority of my pairings achieved comfortable listening volumes with little resistance:
| Brand and Model | Impedance | Volume Set (high gain, 4.4mm) | Hiss (Y/N) |
| Campfire Audio Fathom | 11.7 ohms | 11 steps | Y |
| Drop X Campfire Audio Dark Stars | 9.212 ohms | 13 steps | Y – moderate |
| Dita Audio Mecha | 32 ohms | 13 steps | N |
| HBB X FatFreq Deuce | 18 steps | N |
The xDuoo XA-02 is a powerful source, but it is not without its faults. Hiss is a persistent issue with hyper-sensitive IEMs like the Campfire Audio Fathom or its older siblings, the Andromeda and its yearly iterations. We will speak about subjective sound in future sections.
Bass mode
I am a certified lover of a sloping bass-response – I love the physicality and visceral nature of bass slam and rumble. However, the quality versus the sheer volume of the low-end matters more to me.
Unfortunately, I find that the Bass mode on the XA-02 to enunciate the sub-bass bloat, exacerbating the draggier notes at the end of trailing notes. Consequently, there is a perceived loss of resolution, with the portly low end masking the naturality of the midrange.
Turn to the next page for Sound and Conclusive remarks.
