REVIEW - xDuoo XP-2 - Bluetooth & USB-DAC Amplifier
Specifications
Price: U$110.
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.