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xDuoo XP-2 Bluetooth & USB DAC/Amp

Rating:
4.33333/5,
  1. NymPHONOmaniac
    Much more than a Bluetooth receiver
    Written by NymPHONOmaniac
    Published Mar 12, 2019
    4.5/5,
    Pros - Powerfull amping, portable amp, great sound quality, great construction, good battery life, high gain switch, volume control know, multiple DAC pairing, 192khz-24bit USB DAC
    Cons - Sound quality is better with USB dac than Bluetooth, amping have slight warm to it
    XDUOO XP2 Bluetooth USB DAC AMP REVIEW :

    P3060928.JPG

    SOUND: 8.5/10
    CONSTRUCTION: 9.5/10
    DESIGN: 9/10
    VALUE: 8.5/10


    INTRO:

    To say i'm an XDUOO fanatic is an euphemism, we can say instead i'm a compulsive-impulsive Xduoo products collector since more than 5 years. It begin with my passionate love for the Xduoo X1 and X2 DAP and overwhelming addiction to Xduoo X3 that I still consider the best product they ever made. After, I get interested in there Xduoo XD-05 DAC AMP to conclude this is again an incredible all in one budget audiophile dream. The XD-05 is responsible for my later addiction to deskop and portable amp as well as OPamp swapping obsession.

    SO, when X-TENIK kindly propose me to write a review of this new Xduoo Bluetooth receiver, it fall in a perfect timing due to my new enthusiast about this type of device using an independant DAC to process bluetooth signal. Before I review other BT receiver like the Radsone ES100, I was extremely sceptikal about sound quality this type of technology can offer. Thanks to the AK4452 premium multi channel DAC used in the Xduoo XP2, because it take bluetooth signal to new level and offer tremendous sound performance only find in entry and mid tier DAP. But this isn't all, and what make the XP2 stand appart its the fact it have AUX IN as well so we can use it as a powerfull portable amp. Now let's see if this is too beautifull to be true as I will do my best to objectively review the XP2 and make comparaison with other DAC and AMP.

    You can buy the Xduoo XP2 here:https://www.xtenik.com/product/xduoo-xp-2/

    P3060936.JPG

    SPECS AND INFO:

    Info about AK4452 DAC:https://www.akm.com/akm/en/aboutus/news/20150522AK4452AK4454AK4456AK4458_001/

    xDuoo XP-2 24bit/192khz PCM Bluetooth 5.0 & USB DAC HiFi Audiophile Portable Headphone Amplifier

    Description

    Bluetooth 5.0

    HD Bluetooth Transmission

    High Performance USB Decoding

    Independent DAC

    2 Gain Adjustment

    Bluetooth 5.0 HD Signal Transmission

    Support high-definition signal transmission, through an independent high-performance professional DAC chip decoding, display a complete music signal with a better sound quality than the traditional Bluetooth audio equipment.

    Flipped PC USB DAC

    Professional decoding headphone amps let you listen to better music, USB receiver chips uses high-performance ship SA9123, works in asynchronous mode, supports up to 24bit/192khz PCM signal

    IOS Device USB DAC

    Professional decoding chip, let your Apple device become HI-FI player

    Support up to 24bit/192khz PCM signals (Apple Camera Connection Kit is needed to use)

    Android Device USB DAC

    Professional decoding chip, let your Android device also become HI-FI player

    Support up to 24bit/192khz PCM signals (the corresponding USB OTG connecter is needed to use)

    Two stages of high and low gain adjustment

    Support different sensitivity of the headphones, including in-ear headphones and headphones

    What can it do for you?

    Aux In / Provide High Quality Audio Source/ 2 Gain Adjustment

    Professional amplifier, let you listen to better music

    After Bluetooth / USB HD decoding, provide high quality audio source, you can connect it to the active speakers in your house, in order to effectively improve the sound quality of your speakers

    Power Amplifier Circuit

    The amp section adopts the OP+BUF architecture and its driving force is even stronger! The driver power supply provides +/-5V through a high-efficiency power conversion circuit, which can better drive the headset! The power output circuit adopts the OCL circuit structure, and no output coupling capacitor is required; The bass is calm and clean, and the sound is powerful!

    Specification

    Bluetooth receiver: Bluetooth 5.0, support AAC, SBC, aptX

    Output Power: 245mW@32Ω

    THD+N: 0.008% (1kHz)

    Recommended headphone resistance: 16Ω-300Ω

    Gain: +3/+9dB

    Size: 105*56*15mm

    Frequency Response: 10Hz~100kHz (+/-0.5dB)

    Battery: 3.7V/1800mAH

    USB sampling rate: Support 44.1kHz-192kHz, 16-24bit

    Battery life: AUX IN: ≥15H Bluetooth input: ≥12H USB IN: ≥8H

    USB receiver: Support Android mobile phone with OTG function and 192kHz/24bit lossless transmission at most, computer USB input, support with XP, Win7, Win8, Win10 (it is necessary to install drive), MAC system.

    Weight: 115g



    CONSTRUCION, DESIGN & ACCESSORIES :

    P3060946.JPG P3060947.JPG P3060948.JPG

    UNBOXING is very rewarding here, as Xduoo do not forget any accessories to fully take advantage of its device : it have 1 USB to micro usb for charging and USB DAC, 1 small micro usb to micro usb L cable for OTG DAC as well as micro usb to micro usb type C L cable for newer phone OTG dac, a gold plated aux cable for audio input and a Xduoo silicone Pad double side sticker to hold togheter the Xduoo XP2 with your phone or DAP.

    P3060926.JPG P3060924.JPG P3060921.JPG P3060919.JPG

    CONSTRUCTION is really impressive, but Xduoo rarely if ever disappoint about workmanship. Here its no exception and they go full metal and only piece of plastic you will find is the gain switch and the plastic side where the usb connection are and its to permit bluetooth signal to be properly sent.

    The buttons are metal, the volume know is metal, 95% of body is metal and even the audio jack are metal. This device will sure survive to hardcore everyday use and promise long durability with such a great sturdy construction.

    P3060923.JPG P3060920.JPG

    DESIGN is intuitive yet minimalist. You open the receiver by turning the knob and a green light between 2 jacks welcome you. I you have already selected Bluetooth fonction, it will atomatically connect to you phone or laptop and your ready to enjoy music. If its your first time connecting BT with your phone, perhaps you will have to push the rarely used BT link button.

    INNER CONSTRUCTION is just a caprice of my curiosity about whole construction quality, so here again, I conclude this is seriously well built circuitry-clean and professional with all the stated compenents. But, I don't think it will be easy to change the battery once it die in some years (wich is a drawback to me).
    P3030869.JPG P3030865.JPG

    SELECT button have 3 option that are shown trough light color at side of the button.

    GREEN is for bluetooth mode.

    RED is when USB DAC mode is on.

    GREEN+RED Lights mixed togheter is for AUX in mode.

    There no special color for Audio out, it will be audio in for amp mode and real line out (without volume control) for DAC or BT mode.


    OTG DAC work flawlessly with my LG G6 and was just a plug and play enjoyment, I was very happy to have the L cable to connect it tightly too. Sound do not creat interference or any cliking unlike cheaper otg dac I try in the past.


    USB DAC is same worries free plug and play and offer same sound quality.


    BLUETOOTH DAC was easily findable and once connected for one time, i just needed to open XP2 and it connect by himself on the bluetooth device that was open.


    BLUETOOTH reception is above average and can go up to more than 12meter in open space, as we cannot reivent physic laws, the signal struggle to pass trough thick wall as any other bluetooth device.

    GAIN give extra 9db and will be able to drive properly anything of 300ohm and below, it will not be able to drive at full potential 600ohm headphone and can struggle with 160-300ohm one if they have very low sensitivity.



    P3060951.JPG



    SOUND :

    OVERALL SOUND IMPRESSIONS :

    With the Xduoo XP2, we have a AK dac that remind me of AK4490 dac from Xduoo X3II, but with more bass emphasis. When used as BT receiver we have a warm, weighty sound, that tend towards a smooth overall rendering. Sub bass is more emphased than mid bass, mids are quite linear, not bright, near organic sounding, treble is smooth but well layered with good tone and soft timbre.

    The sound is quite energic because of weight impact, but still warmly rendered, far from being analytical, it can remind of analog type of sound, laid back but resolved and greatly enjoyable.

    As well, there a sens of transparency to layers, wich soundstage panoramic widness help to heard.


    USB OTG DAC mode have the best sound rendering, it is clearer and more balanced than with Bluetooth. The bass have more control and details even if still slightly pushed fowards. Clarity of imaging is impressive. Details retreival are above average but not analytical, it feel natural and never cold or artificial sounding. The fact you can listen up to 192khz/24bit music files is a proof that the DAC is fully take advantage off in USB mode because there limitation to APTX 5.0 Bluetooth (48khz/24bit).


    BLUETOOTH mode sound very similar, but little less agile and clear. The big difference is in bass warmness that feel less controled and stole some space in soundstage as well as clarity. Mids have little less body too, but overall sound is excellent, with a wide airy presentation and good transparency.


    AMP mode is very usefull and make this BT device stand appart because of this great feature. It’s quite powerfull at high gain, and I think the amping section is responsible for extra bass and warmness we have with overall XP2 sound rendering, This is up to the pairing for getting excellent sound, but earbuds lover should really think about this Bt Receiver as the go to solution for enjoying full potential of earbuds on the go, XP2 is just from another league for amping earbuds, headphones or hard to drive iem.


    COMPARAISONS:

    P3060934.JPG P3060932.JPG

    VS Radsone Earstudio ES100 (100$):

    Here I compare mostly to the unbalanced output of ES100, because XP-2 do not have balanced out. Will add extra observation about 2.5mm balanced out of ES100 in they end.

    I compare the 2 devices using my LG G6 as Bluetooth source, all file was ripped in FLAC. Music style are diverse, wich include indie rock (Thus Owl), Classical, Modern Jazz, electronic and Singersongwriter (Jessica Pratt).

    I use these headphones for comparaison : Final Audio E2000, Koss Portapro, NiceHCK EBX earbuds, Hifiman HE-300.

    P3060930.JPG

    CONSTRUCTION of Xduoo XP-2 is from another league here, its all black metal that feel sturdy and have a high quality look, but its heavier than ES100 as well, 10 times heavier in fact as it weight 115g vs 18g for ES100. Output jack are made of metal, and again, of better quality than plastic one of ES100.

    Anyway, whole construction of ES100 with the exception of the metal clip is plastic, and the size is 4 times smaller wich make the ES100 a real portable bluetooth dac-amp that can be clip on your clothes. The Xduoo XP-2 fit easily in your pocket, but is still less portable.

    Even is way smaller, the ES100 have more buttons and features, you can change tracks, pause and play, and unfortunately, you cannot with the XP-2, wich is a real drawback. Biggest difference is the fact ES100 have 2 outputs, one unbalanced and one 2.5mm balanced that isthe star of the show with this device as it give more power and clearer background noise floor.

    XP-2 have one 3.5mm output that is way more powerfull than ES100 and have a High gain switch that is very usefull as I prefer switch to firmware interface gain.

    Big plus for ES100 here is the dedicated Earstudio application that permit to customise amping power as well as sound in multiple of way. The Xduoo XP2 do not have dedicated application at all.


    SOUNDSTAGE feel wider with the XP-2, wich is especially hearable with headphones of more than 64ohm like the Portapro of Hifiman HE-300, wich sound a little thin and congested on the ES100. With lower impendance iem or earbuds, the ES100 show its superior talent for precise layering in a deeper soundstage as I can hear with Brainwavz B200 that lack clarity with the XP-2. In other hand, more demanding headphone will gain in soundstage and natural imaging, wich clearler show the pairing with trebly Hifiman HE-300 that sound very airy and gain in bass and softness with this pairing at high gain.

    BASS of the XP-2 feel more extended as well as having more lower end presence with a softer mid bass presentation than more punchy and brighter ES100. The fact sub can stole some clarity to mids of XP-2 make the ES100 better controled, but less thick sounding too. Here the XP-2 will benifit high impendance headphones or bright sounding iem, while the ES100 will give extra clarity to low impendance iem or headphones as well as extra enery.

    MIDS of ES100 are more fowards and bright, feeling more detailed but less wide and transparent than the XP-2. Overall sound of Xduoo is more natural and soft, while the ES100 feel analytical and more energic. Vocal can sound a little nasal with ES100, wich will not help for pairing with hissy earphone, XP-2 have great natural mids presence, warmer and more transparent than ES100, but the layering is less agile and detailed.

    TREBLE extension of ES100 is more pushed, wich give more microdetails and texture than XP-2, XP-2 feel smoother with upper treble roll off and is more permissive with hissy music or earphones. It have better tone than ES100, and fuller timbre. ES100 have a more fowarded texture and clinical approachthat give extra resolution to sound layers where the XP-2 can feel too laidback.




    VS ALPHA & DELTA BT RECEIVER(30$) :


    P3060953.JPG P3060956.JPG

    So this is very different BT receiver, and one is 3 times cheaper than the other, but as I do not have a big collection of this type of device, I think it’s interesting to compare it for consumer thinking about doing an upgrade for higher priced receiver.

    Well, if you just have very sensible IEM that are very easy to drive and offer tremendous sound (aka, no cheap immature IEM), I think perhaps you don’t need to buy a powerfull DAC-AMP BT receiver Plus Stand alone AMP. But if you have any demanding iem or a pair of headphones (whatever the impendance), yeah, must certainly you will benifit from a BT receiver that have some amping power to it, because no, the Alpha Delta do not have lot of amping power, in fact, perhaps your phone have more.

    Alpha & Delta BT receiver is an ultra small portable device, wich is perfect to transform your iem in wired BT one, for that, I suggest you buy a small mmcx cable and begin this budget iem collection with detachable cable because 90% of BT earphones have….wire.

    Being extra small, it really cannot compare to amping power of XP2, and we don’t talk about high gain here. Just the fact XP2 is a standalone portable amp too justify the price jump, but the sound is suppose to be better as well due to an independant dac chip, aren’t it??
    To be honnest the sound paired with easy to drive IEM is quite similar, the soundstage of Xduoo being wider but warmer, weightier too, while the Alpha Delta receiver is more analytical and cold sounding. But, when you use any less easy or capricious to drive iem , earbuds or headphones, the A&D begin to struggle and sound thin, lacking in power, while the XP2 begin to shine even more expanding soundstage and give extra weight and presence to bass and mids, and being able to drive near anything up to 300ohm….this IS the big difference,

    So, this is a 30$ device against a 110$ one...and XP2 win everywhere but for ultra portability, as well as tracks changing buttons, wich even a cheap device have, hum.

    Sound improvment is sure there, but biggest plus is the amping power and extra feature like usb dac and amp with audio input etc.

    VS LG G6:

    Did I really need to do this?
    G6 sound congested, dry and have background hissing compared to vivid XP-2 sound.
    SOUNDSTAGE is immense compared to frontal G6 presentation that lack deepness and feel artificial.
    BASS is way better controled and have rounder more weightier presentation.
    MIDS are wide and lively, they are well layered while the G6 have them stick on a cardboard soundstage.
    TREBLE is clean, with hint of brillance and great layering while the G6 feel dry and bright and veiled.

    (extra) PORTABLE AMP COMPARAISON WITH IBASSO BOA D2+.

    I will not compare DAC section here, just amping because BOA is not a BT receiver.

    The BOA have about same amping power than XP2 but a longer battery life that can go up to 30H.

    Construction is pretty basic and look more like a DIY project than a real professionaly made one, so the Xduoo XP2 with is from another league here and more portable as well due to less thich body.

    Overall sound of BOA D2+ amp section is brighter and more grainy and lack the smooth finess of XP2. As well, background noise floor of XP2 is blackest and near perfect while BOA D2+ have some hissing.

    BASS have more body and impact with XP2 and can feel quite thin with the BOA.

    MIDS are brighter with BOA, with it have thicker more natural timbre with the XP2.

    TREBLE is strangely affected by BOA rendering and became more dry and grainy, this can give the impression the BOA is clearer but in fact it have more distortion in sound and affect highs negatively.



    PAIRING IMPRESSIONS:


    P3060917.JPG


    With IKKO OH1 Hybrid :

    This pairing sound extremely good, even if the OH1 are on the bassy side already, here the overall control seem better and gain in body timbre, this is mostly due to expension of soundstage given by plenty of amping capabilities of XP2.

    MIDS too open up in the big soundstage, and feel less rough in upper range, as well, they gain separation from other instrumental. Overall clarity is excellent as well.

    Treble feel smoothed out a little, around 8khz and 14khz, but it do not stole details, just some brightness there and there, wich in fact benifit the OH1.




    With Hifiman HE-3000 :


    P3060945.JPG

    Again, this pairing is excellent, as the HE-300 can sound too cold and analytical, here the XP2 warm the sound as well as injecting some more bass to it, wich was lacking before.

    The bass gain in sub and impact and give extra body to mids.

    MIDS became more natural and less grainy, more bodied and have a wider presence.

    Treble wich was very fowards is softened too, giving an overall darker tone that i feel make the HE-300 more musical, as highs was to sharp and agressive before.

    For once rightly amped by a portable amp, the HE-300 became a very listenable headphones and we can thank the XP2 saver as I will surely used them more because of him.

    P3060935.JPG

    With the Faaeal 64ohm earbuds :

    (XP2 Bluetooth+high gain)

    At 64ohm, I feel these need proper amping and will sound too thin with not enough juice.

    Here, again, everything look to open up more and gain in weight and presence, but not much in timbre.

    The bass became way more controled and bodied, wich take me by surprise because I didn’t think the Faaeal can offer this type of round bass in a clear not distorted way.

    MIDS wich was already fowards became better layered from rest of instrument, vocal becaming softer, more present and more transparent, wich give a less opaque mid centric soundsignature by adding extra air and widness to soundstage.

    TREBLE is more extended too, especially around 10-14khz, where the Faaeal was feeling too soft before, as if extra amping give the highs better decay and brilliance.

    All in all, a superb pairing that clearly benifit this earbuds.

    CONCLUSION:

    P3060938.JPG

    Xduoo make some error lately with some of there DAP like the D3, so I was a little afraid this device don't hold well its price ratio performance.
    I was so wrong, so so wrong!
    It's the opposite that happen, as even if features look minimalist at first, we fastly discover that the XP-2 is way more than a simple Bluetooth receiver. The genius idea of Xduoo here is to make the XP-2 a stand alone portable amp of great quality that offer powerfull clean amping with physical high gain button. This permit to the usb or bluetooth dac to be way more versatile in amping power than all other bluetooth receiver on the market right now.
    The sound quality is a clear improvment from any laptop and surely any phone, its clear, immersive, wide and lively withouth any congestion or distortion to the sound.
    Sure XP-2 is a little bigger than Radsone ES100, but it is still is very portable and will offer more pairing or amping possibilities that can benifit your hard to drive headphones, non amped usb DAC or any of your DAP with line out.
    If you search for a simple and intuitive Bluetooth receiver that will be able to properly amp any of your headphones, earbuds or iem, I'm convince only the Xduoo XP-2 have enough muscle for this task.

    For more reviews and audio related news and stuffs, give a look to my website HERE

    images

    1. P3060944.JPG
      cqtek, B9Scrambler and snellemin like this.
    1. Preachy1
      "and overwhelming addiction to Xduoo X3 that I still consider the best product they ever made."

      YEEEEESSSSS!!!!!!!!!!!!!!!!!!!!
      Preachy1, Mar 13, 2019
      Nymphonomaniac likes this.
  2. Wiljen
    Xduoo XP-2 - The Jack of all trades
    Written by Wiljen
    Published Mar 10, 2019
    4.5/5,
    Pros - Solid build, great battery life, lots of functionality.
    Cons - Returns to Bluetooth mode on power cycle, DAC adds some mild coloration to sound.
    The Xduoo XP-2 falls into a class of products that is being advertised as a bluetooth Amp. What this means depends on which vendor you are talking to. In this case the XP-2 has the capability to act as a bluetooth receiver from a source device and then output to a set of wired headphones, and can be used as a purely wired amp via the 3.5mm input port or as a USB dac/amp by connecting a source via usb.



    Packaging:

    The Xp-2 came double boxed with a white outer package with graphics on front and details on rear and a black lift-top style inner box done in much more subtle tones.

    [​IMG][​IMG][​IMG]

    The inner box is a lift-top design with a shelf the XP-2 sits on, and a compartment underneath with a wealth of cables that come with it. The XP-2 comes with 2 3.5mm cables (one 90º and one straight) for use with wired sources, and two USB OTG cables (one USB-C on both ends and the other USB-C to Micro-USB) to allow the XP-2 to connect to just about anything. It also comes with a USB cable for charging the device, a manual, and warranty card hiding in the lower compartment.

    [​IMG] [​IMG] [​IMG]

    Build:

    The Xp-2 is very solid and has good heft. Size-wise, it is roughly the same size as the Cayin N3. Slightly narrower than a deck of cards with a similar length. Weight is about double that of a desck of cards. While still very portable, the construction gives the user some assurance that it will withstand the rigors of pocket use. Jacks are countersunk in the face and the volume knob is well protected. Buttons and switches on the side of the player are very tactile and require an intentional push to change modes so again, worry about pocket carry is minimal. The bottom of the device has two micro-USB ports, one for charging and a 2nd for data traffic. This allows the unit to be charged while in use and prevents excessive drain from the phone when used as a usb DAC as the data line does not pull the 500ma current typical of USB.

    [​IMG][​IMG][​IMG]



    [​IMG]

    Internals:

    Xduoo advertises the XP-2 as using the SA9123 USB Controller for input, and the AKM 4452 DAC chip. I found several references to opamp/buffer design in Xduoo's advertising materials, but none specifying which components. So I did what any normal person would. I took it apart. As can be seen below, the Opamps are TI OPA1652 and OPA1662 chips with a LMH6643ma buffer following. I tried running the QR code on the bluetooth antenna (lower left) but was unable to get further than the literal translation (HNY1809001).

    [​IMG][​IMG][​IMG]



    Features:

    I mentioned the modes the device can be used in during the intro, but lets look at these in a bit more detail.

    The simplest mode is as a wired Amplifier. In this mode, input is via the 3.5mm aux in/out port and output is via the 3.5mm Phone Jack. Xduoo advertises the amp circuit as having ± 5V rails for maximum drive which provides roughly 250mW @ 32Ω. I found the little unit had no problem powering most headphones including the 600Ω Beyer 990 and the T50rp which are notorious power sponges. While the t50rp couldn't be pushed to ear-splittling levels, with the gain on high, it had more than enough power for reasonable listening levels. Most fairly sensitive IEMs and even some low impedance/high sensitivity cans will be better served by the low gain mode as high gain leaves very little usable volume control before it gets loud enough to be troublesome.

    Next up, USB DAC Mode. I tested this using the iPhone 8 with a camera connection kit, an HTC m11, the Cayin N3, and the Moto Z3 Play smartphone. The Xduoo worked effortlessly with all except the Moto which refused to detect it as a USB DAC. On the Iphone and M11, all apps worked well and the unit's battery held up well to all day work sessions. I was also able to connect the XP-2 to a Windows 10 PC and use it as a DAC/amp using the native win10 drivers.

    It should be noted that the USB Dac mode can be combined with bluetooth headphones so the phone can be left in a pocket or so the user can walk around the office and not be tethered to the DAC.

    The third mode is the bluetooth mode. In this case, we are using bluetooth between source and the XP-2 and the XP-2 is providing both DAC and amp functionality. In this mode, the gain switch is still in play since the headphones are wired to the XP-2 and the bluetooth connection is prior to the amp stage. (When using bluetooth headphones with the XP-2, the gain switch is bypassed). In this mode I was able to again pair the laundry list of phones and PCs to the XP-2 with no issues (even the moto works this way) and connectivity was solid as long as the XP-2 and source device remained within 5-10 feet of each other. This is nice as a few devices I have tested have suffered from cut-outs when one was in a pocket and the other not. Battery life in bluetooth mode is lessened somewhat, but it was still able to put in an entire workday (8 hours without needing a charge). (When used as a wired amp, I was able to get 2 days out of it before it cut out).

    (Section pulled while rechecking- may have been in error)

    Controls

    Most XP-2 controls are on the side of the unit. The exception being the on/off/volume knob on the top with the 3.5mm ports. Looking at the right hand side of the unit from left to right, we have the bluetooth LED (marked BT), the Bluetooth Pairing button, the gain Switch, and the mode selection switch and LED.

    [​IMG]

    Most of these need little or no explanation, but the Select option does have a couple quirks that are worth noting. First, the unit always powers on in G-BT mode. (Bluetooth), and must be changed to R-USB mode or RG-Line in mode at startup each time if so desired. The G, R, and GR (which turns out yellow) are the designations for the LED color displayed in each mode. So when powered on, the LED always starts out green. The issue I ran into with this is that when pairing the unit using USB, most devices will not see the unit unless it is in USB mode and since powering the unit off and back on reverts it to Bluetooth, it makes using it as a portable usb dac paired to a phone a bit more fiddly than I'd prefer. A last mode memory would go a long way here if you are reading this X-duoo.



    Sound

    This is a tough section to write as the unit has several different answers to the question, "how does it sound?". If used purely as a wired amp, the XP-2 does an admirable job of being colorless and doesn't introduce any notable changes in tone. When used as a USB Dac/Amp, I did find the XP-2 to add a minor boost in the mid-bass and again in the lower treble. I have to assume this is part of the tuning of the dac itself as it was not present when used as a wired amp. When used with a bluetooth connection from source to XP-2 and wired headphones, the slight boost was again noticable. I didn't find the boost pronounced enough to be bothersome in either case, but do think those looking for a perfectly neutral platform would want to know up front that the XP-2 does add some coloration to the sound in certain instances.

    Conclusion

    The XP-2 is a jack of many trades and does most things quite well. Battery life is impressive for a device its size, and power is more than adequate for most real-world situations. I found the XP-2 to be a very solid alternative for those interested in something like the xDSD at a considerably lower price point. The unit is no larger, every bit as solid, and other than using a slightly less potent DAC chip, offers most of the same feature set. Most of us liked the xDSD when it came out not long ago and called it an excellent value, so what do you call something that offers the same functionality at 1/3 that price? I'm calling this one "mine", you can call your whatever you like when you get it.

    [​IMG]
      steven.lambert1026 likes this.
    1. View previous replies...
    2. NymPHONOmaniac
      Don't talk much about sound aspect....I find it utterly important, especially fo this warm sounding dac and amp. Quite an impressive device, but it have an ''analog'' like soundsignautre to me. Its like the opposite of Radsone ES100 in all aspect, for the better and the worst.
      NymPHONOmaniac, Mar 10, 2019
    3. Wiljen
      I found it warmer if using it as a dac and did mention that, when used as a straight amp using 3.5 input and output, the boost in the mid-bass and lower treble is not as noticable as when using it as a dac in either USB mode or bluetooth.
      Wiljen, Mar 11, 2019
    4. Brooko
      How did you pair to headphones? I have it in front of me now, and I can't get it to pair with a Mobius (via Bluetooth) so I can test as a Bluetooth transmitter - with wired connection to DAP (as per your review). How did you do it please?
      Brooko, Apr 26, 2019
  3. Cinder
    There’s Power in Versatility
    Written by Cinder
    Published Mar 23, 2019
    4.0/5,
    Pros - Incredibly Versitile, light-weight, good construction, dedicated charging port, good cable selection, two gain modes, good pairing behavior, painless drivers on Windows
    Cons - no LDAC/aptXHD, no USB-C
    [​IMG]
    Xduoo, while not a household brand in the English-speaking markets of the West, has built many compelling products that serve the audiophile-on-a-budget market for the past couple of years. Today I’m reviewing their XP-2 DAC/AMP Bluetooth receiver. Its got a plethora of features that give it broad acceptability in a diverse collection of source chains.

    You can find the XP-2 for sale here from X-Technic, for $110.

    Tech Specs
    • Connectivity: Micro-USB OTG, Bluetooth 5.0
    • Codecs: AAC, SBC, aptX
    • USB Sampling Rate: 44.1 kHz-192 kHz, 16–24 bit
    • Output Power: 245mW @32 Ohms
    • THD: 0.008% (1 kHz)
    • Battery Capacity: 1800 mAH
    • Battery Life: Aux ≥ 15H, Bluetooth ≥ 12H, USB ≥ 8H
    • Gain: 2-modes
    Sound Signature
    Sonic Overview:
    The XP-2 sounds very linear and transparent. It doesn’t impede the sound of music at any point, whether it's only using a passthrough amp or is actually using its DAC for decoding purposes. That said, Bluetooth mode does introduce some mild warmth into the low-end of the sound signature, though this doesn’t affect the overall stellar dynamics that the XP-2 presents. This could be due to any number of factors but is likely the result of some decoding artifacts introduced inside the XP-2’s receiver. I am glad to report that the shift in presentation is so subtle that switching between Bluetooth and USB/Aux modes isn’t disorienting at all.

    Packaging / Unboxing

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    Build
    Construction Quality

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    The xDuoo is pretty compact for a device of its form-factor. The little device packs a good amount of tech within its aluminum frame. Said frame is constructed with precision, not presenting any unwieldy seams or uneven surfaces. While I would have preferred to see xDuoo not use such difficult-to-remove screws so I could see exactly what’s going on under-the-hood, I can understand why they wouldn’t want the average-joe tampering with a device that is designed around creating high-voltages.

    The XP-2’s buttons and sliders are all made of metal, and they are fixed to the frame well. While the buttons have a minute amount of shuffle, I can accept that for a reasonably-priced device such as this. Beside the Select button is an LED that turns different colors depending on what connectivity mode it is in. To the left of the BT Link button is another LED that acts as a Bluetooth pairing indicator.


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    xDuoo did a really good job staging and tuning the feel of the XP-2’s volume knob. It turns very nicely, giving off a premium feel that is reminiscent of the mechanism inside the FiiO A5.


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    The bottom of the device features two Micro-USB ports. They are sturdily connected to the frame and do not wiggle about. The ports hold firmly onto the cables that are inserted into them. Beside each port is an LED status indicator that gives the user back useful information about whether or not the port is functioning correctly in a given mode.

    Functionality
    The XP-2 pairs easily with my HTC U11, LG V40, iPhone X, and Huawei Matebook X. This is not as easy a feat to accomplish as it may sound, as Bluetooth is a mess of implementation that varies wildly across vendors and platforms.

    I also found that the XP-2 had enough juice to easily handle my IEMs, and just enough to drive my Advanced Sound Alpha while in high-gain mode. Oddly, I was able to get more volume out of the XP-2 when using it in Aux mode than when it was in USB mode with my V40. I’m willing to bet that this is a small detail that can be adjusted with a firmware update.

    As far as battery life goes, I was able to get roughly the advertised times out of the XP-2. Here are my battery life averages per day over two weeks:

    • Aux Mode: 14.3 hours (low-gain, IEMs)
    • Bluetooth Mode: 12.2 hours (low-gain, IEMs)
    • USB Mode: 7.7 hours (high-gain, planar headphones)
    I’m satisfied with the given times. The disparities between my actual results and the expected times were low enough that I can chalk them up to either environmental factors or flaws in my testing scheme. What really matters is that with these times, I never found myself out of juice in the middle of the day, no matter what configuration I was using. Further, since the XP-2 has a dedicated charging port, you can charge it while you use it, meaning it can be put to use indefinitely should that be what you desire.

    Accessories

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    Inside the box you’ll find:

    • 1x 3.5mm to 3.5mm cable
    • 1x Micro-USB to Micro-USB OTG cable
    • 1x USB-C to Micro-USB OTG cable
    • 1x USB-A to Micro-USB OTG cable
    • 1x xDuoo branded carry pad
    These are about as many accessories as one can expect from a device such as this. While some rubber retention-bands could have been useful, I’d imagine that they are common enough to not impede an audiophile from using the XP-2 in a meaningful way. The cables included in the box are built sturdily enough. They cover all the use cases that I could think of given the XP-2’s varied input scheme. I find it hard to complain about what xDuoo went with here.

    Summary
    The XP-2 is a well-rounded device that can be used in a myriad of ways. While you won’t be driving any headphones with monster impedances, you can easily power the more reasonably-specced headphones such as the Advanced Sound planar lineup, Meze lineup, and essentially everything that the likes of Bose and JBL produce. Sensitive IEMs are welcomed by the XP-2’s low-gain mode, so fret not balanced-armature users. While USB-C and aptXHD/LDAC would be welcomed additions that would really set the XP-2 aside from its competition, for $110 I find the XP-2 to be a reasonable proposition as is. So if you want a multi-functional DAC for whatever device you have, the XP-2 can probably fit your needs.

    As always, happy listening!