The xDuoo XA02 is a combines a DAC and a headphone amplifier in one to provide you with high output power while keeping the footprint small: it has, in fact, enough power to drive anything out there while still fitting easily on any desk.
Disclaimer: I received a free unit from Shenzhen Audio for the purpose of this review. They sell the XA02 for $199. Additional information on the manufacturer’s website.
TL;DR: recap
| Pros |
Cons |
| + Solidly built with all metal
+ Lots of features + High power output + Neutral sound signature + Great value |
– Background hiss and “pop” sound when playback starts
– No XLR output to use as a pure DAC |
Rating: 8/10
Packaging & Accessories
The xDuoo XA02 comes in a cardboard box which contains the device itself, a USB to USB-C cable (which, interestingly enough, is of the USB 3.0 variety), a power cable and a manual.
Design & Build
The xDuoo XA02 uses the company’s characteristic two-tone design: the chassis is dark grey with white etchings on it, while the volume knob is a bright red. This creates quite a striking contrast. This is also coupled with distinctive design choices when it comes to the shape: the chassis has chamfered lateral edges with holes on top, while the front has vertical ribs running across its front. The XA02 is surely quite unique and a clear departure from the traditional all-black hi-fi design.
The front hosts a 6.3 mm unbalanced jack, a 4.4 mm balanced jack, a 1.3″ OLED display, a menu and a Bluetooth button, and the volume knob. On the back we find stereo RCA output, coaxial and optical input, USB input and a USB port to update the firmware, the Bluetooth antenna and the power connector and power switch. It should be noted that the only way to power the device on and off is to use the power switch on the back, which is less than ideal as it limits the positioning options.
As it is customary for xDuoo, build quality is very high and I can find no faults in how the XA02 is assembled. The materials are solid and finished to a high level.
The volume wheel is actually a clickwheel: you can push it to interact with the menus. It also offers acoustic and tactile feedback when you turn it as it is a digital steeped wheel, with each step being 1 dB. It has good weight to it while not requiring any effort to turn it.
Features & Specs
The xDuoo XA02 offers a rather complete range of inputs which includes USB-C, optical, coaxial and Bluetooth; the latter supports the SBC, AAC, aptX, aptX HD, aptX LL (low latency) and LDAC codecs, affording the device high-quality audio transmission.
When it comes to output, the options are slightly more limited. Although xDuoo boasts “completely balanced” signal processing and output, you only get balanced output with headphones, as there are no XLR outputs on the back – a fact which keeps the footprint down on one hand but, on the other, limits the possible usage of the XA02 as a pure DAC.
As the XA02 has no remote control, interaction happens through the (clickable) volume wheel as well as the two buttons on its side.
xDuoo XA02 |
| Input | USB (up to 32 bit / 384 kHz PCM, up to DSD256, MQA) Optical, coaxial (up to 24 bit, 192 kHz; DSD64 via DoP) Bluetooth (SBC, AAC, aptX, aptX HD, aptX LL, LDAC) |
| Suitable headphones impedance | 16 – 600 Ω |
| Output impedance | N/A |
| Maximum output power | – 910 mW (32 Ω, single-ended) – 2,000 mW (32 Ω, balanced) |
| Frequency response | 20 – 60,000 Hz ± 0.5 dB |
| THD+N (@1 kHz) | < 0.0004% (line out) < 0.0004% (balanced) < 0.002% (single-ended) |
| SNR | > 121 dB (line out) > 121 dB (balanced) > 119 dB (single-ended) |
| Crosstalk | 118 dB (line out & balanced) 71 dB (single-ended) |
The xDuoo XA02 uses the ESS Sabre ES9039Q2M DAC chip, which is originally meant as a low-power chip for mobile devices. The output stage is apparently a discrete Class A setup, which has lots of power on tap: at 2 W on the balanced output, it is very significant and more than enough to drive any headphones out there.
Sound
I tested the xDuoo XA02 with various headphones, including a Sennheiser HD 6XX, a HiFiMAN HE1000SE and an IO AUDIO VOLARE.
One thing I immediately noticed when using the xDuoo XA02 is that it is perfectly silent, even with low-impedance earphones. This changes, however, as soon as you start playing any content: there is a small “pop” sound followed by a constant hiss. While both are only really noticeable with low-impedance earphones and quiet tracks, they are still there nonetheless. This is probably caused by the fact that the XA02 uses a Class A amplifier circuit which is switched off when not in active use, so you can’t hear the noise until you start playing something.
In terms of frequency response, I cannot hear any deviation from neutrality: the xDuoo XA02 sounds perfectly flat and therefore it does not impart any colouration to sound, which is a net positive (as an example of why, because it won’t only pair with some headphones). It offers a lot of power, which is enough to drive any headphones out there. Even when using it with the single-ended 6.3 mm jack, it has enough power to drive anything.
The bass boost feature works well and gives a small boost to sub-bass, which does not get in the way – it’s a gentle uplift which goes a long way if you just want a bit more bass.
Final Thoughts
We might call the xDuoo XA2 an integrated headphone amplifier: it offers a DAC stage and a headphone amplifier and the two are made to work together; the RCA output is mostly for added convenience, rather than one of the main features on offer (which is a bit of a missed opportunity, but not a major one). As a headphone-centred device, the xDuoo XA02 offers significant power output which is more than enough to drive virtually any headphones on the market; the presence of a balanced output gives you added flexibility.
Overall, the xDuoo XA02 is a very competitively priced device which can work in any existing setup or as a very good starting point for those new to the headphone world.
