xDuoo XP-2

REVIEW - xDuoo XP-2 - Bluetooth & USB-DAC Amplifier



Website - xDuoo




Specifications


Price: U$110.

The XP-2 unit was kindly provided by Xtenik store, official xDuoo products distributor. XP-2 is available here.

The box is the usual deal from xDuoo products, outer white box with a picture of the device and specifications on the back side, and inner black box holding the unit and set of accessories. The package includes the needed cables and some extras:
  • 3.5mm to 3.5mm interconnector audio short cable
  • Micro USB to Micro USB cable
  • Micro USB to Type-C USB cable
  • USB charging cable (micro to Type-A)
  • Silicone (adhesive) pad and extra velcro pads

A rather complete pack, maybe just missing a cable for iOS devices for a DAC use.






Design

As a portable device, the XP-2 is well designed having a good build quality similar to some previous xDuoo products like the X10 or Nano D3 and just behind the XD-05 with its tougher build. The outer chassis is all CNC machined aluminum which looks very solid yet maintains a decent weight and dimensions for the portable use. The volume knob too is made of same metal alloy, while the only section where plastic is applied is on the upper rear part, apparently for the better Bluetooth antenna signal. The corners are well rounded and the finish is very smooth with the all matte black color on it.





The layout is simple and logical. The front panel holds the volume knob on the right side, which also works as the power on/off switch, and two 3.5mm audio ports, 'headphone out' at the left and 'aux' for audio line-in when used as regular amplifier. There is also a small LED that indicates the power status. The knob is not particularly tight, though not loose either, but can be turned to a higher volume without much effort, so better be aware.

The XP-2 resets back to the BT mode whenever turned on; a minor issue.



On the rear panel there are the two micro-USB ports, one for charging and the other for DAC use, each of them with a corresponding status LED indicator. Type-C USB ports would have been more convenient for modern devices nowadays, but nothing to complain about.


On the side panel there is the gain switch, low to high, which adds a 6dB boost. A button to toggle between the different XP-2 modes (Bluetooth, USB DAC, and Line in) and its LED indicator that changes color depending on the current mode. And lastly, a BT link button for pairing the device if needed.

Multi-functionality

For hardware, the xDuoo XP-2 adopts a AKM AK4452 DAC chip (that if not wrong, is newer over the one used on the X3 II player) with support up to 24bit 192kHz, and an output power of 245mW (at 32 Ohm). Decent numbers for an entry portable device at this price point, but more important are the different features this device supports. It can be used as any standard portable amplifier or as external DAC, and also work as a Bluetooth receiver. As both amplifier and USB DAC the XP-2 works without issues, whether connected to a PC or portable player (and also with those that support DAC line-out).




As for wireless usage, the XP-2 uses the new Bluetooth version 5.0. Definitely a good choice from the company, however very limited regarding codec support with only AptX, AAC and SBC, but not the higher ones like AptX HD, LDAC and such. It is a downside, especially considering that various and much smaller Bluetooth receivers can support the hi-res options. Nonetheless, the wireless connectivity is very solid, maybe thanks to the 5.0 BT applied here and the range is very decent too.

The XP-2 lacks playback controls for wireless use. The 05BL module for Bluetooth addition on the XD-05 already had the needed three playback buttons, meaning it was not something impossible to implement on this model, especially as wireless option would be a selling point here. Yes, the XP-2 packs the better battery, more power and better built over compact wireless amplifiers, but it can result annoying to use the phone or player controls instead. In the end, it may be just getting stacked along the music device, making no difference over using the traditional 'wired' setup.


Battery

Another strong advantage of the XP-2 lies on the battery time. It may be larger than other compact Bluetooth amplifiers, but that lets it have a larger battery capacity. Both as a standard and as wireless amplifier the battery can hold close to the stated 15 and 12 hours times. On USB DAC option it goes lower to the average, though.


Sound Quality

Main gears:
final E5000 & E4000, final Sonorous II, HIFIMAN Sundara, SendyAudio Aiva, Meze 99 Classics, iBasso IT04 IT01s, Periodic Audio Be & Mg, VE Zen Lite (320ohm).

Sources:
Fiio K3, Cayin C5, xDuoo XD-05, Fiio M6, Samsung Galaxy 7, Nexum Aqua+.

The XP-2 has plenty of power for headphones that demand a moderate level of extra output strength without reaching much more than half of the volume knob even on low gain set. Driving earbuds with around 150ohm impedance is just fine, and so is with (relatively) lower sensitivity rate items of 90~95dB (e.g., final E5000 and Hifiman Sundara). With less efficient gears like the VE ZEN 2 (with a much higher impedance of ~300ohm) the low gain on the XP-2 was not loud enough even at maximum level. Setting the gain to high is a must but still with a high turn of the volume knob. However, the sound performance is not enough to reach the best dynamics and sound stage; still acceptable for an entry amplifier at the ~$100 mark. With easier to drive sets like the Meze 99 Classics and final Sonorous II, the XP-2 works very well (even though not a favorable match in terms of signature). Also with the new SendyAudio Aiva, relatively efficient for planar headphones, the XP-2 can drive them with no issue without the volume reaching half of the steps. There is similar effect with the E4000 too. I don't have really hiss-prone IEMs (at least not with my current sources), but there is no noise with low impedance hybrids like the DN-2002, DK-3001 or IT04.



As for the sound quality, considering its price the XP-2 fares well for an entry model amplifier. Disregarding the different functions it packs, the sound is very competent in terms of detail, control and resolution; though it has a noticeable added coloration that, while fairly linear in response, stands away from being a neutral sounding source.

There is no bass gain option on the XP-2 and definitely not needed as the low end is already boosted. It doesn't sound bloated or overwhelming but shows a strong emphasis through the whole bass frequency line. The definition is good and so is the speed, nothing especially tight or particularly dynamic but decent in separation. Lower instruments are weightier with a slower, deeper decay.

The midrange sounds subdued and more reserved next to the greater bass emphasis. It is missing authority and can sound dry and plain. The detail is there, just doesn't sound forward or musical enough. For instance, the final E5000 in-ear and Hifiman Sundara planar, both that benefit with some amplification, are missing their remarkable openness and fullness in the midrange.

The highs continue a similar laid-back and smoother presentation; not as boosted as the bass but a bit more present than the whole midrange. There is not much of a gain in terms of extension or resolution, and there is some lack of air too. Even so, the XP-2 sounds fairly natural for the price when compared to smaller gears like the M0 or Aqua+ that while have more energy on the treble, can also sound artificial.

Differences between the wired and wireless mode are not too significant, at least not major changes in tonality or overall presentation. There is still some loss of quality and limitations on the soundstage and extension; a less sub-bass reach and a tad more artificial treble, leading to a more mid-bass perception and less detail, but again, nothing too critical.  

The XP-2 pairs better with neutral to bright or slightly mid-forward sets adding a warmer tonality and more body to the bass. On the other hand, with already warmer or bass oriented gears, the sound gets out of balance pushing too much emphasis on the lows, like adding a bass boost; for example, the Periodic Be can sound bloated and uncontrolled in the bass and even more distant in the mids. While the presentation won't sound too closed or congested, there are no major improvements in stage dimensions. The Meze 99, for example, which have a wider stage for a closed over-ear design, sound kind of limited.

Expectedly, the XP-2 is not a replacement for the greater performer XD-05, especially with the op-amp rolling options, but as a USB DAC it has more power than the Fiio M6, and better control (and less distortion) than the M0 or M3k. The Cayin C5 is brighter and more resolving but leaner in the midrange and more aggressive overall, whereas the XP-2 is more forgiving and laid-back.