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FiiO X5 High-res Portable Music Player

  1. GhostPhantom
    Fiio X5
    Written by GhostPhantom
    Published Jan 22, 2017
    Pros - sounds great, when it isn't cooking itself
    Cons - had 2 units overheat
    Bought my Fiio X5 and it worked great for a few months, then one day, it got very hot ! so I sent it back for a warranty replacement, and it worked great until for just over a year, and now the replacement has done the same thing, will not power up, plugging in the charge cable, the charge light stays green, and the unit gets hot, so since it is out of warranty, I popped the back off, and checked out the battery, it isn't the battery that gets hot, but the circuits under the battery ! I won't be buying another Fiio player
     I used it 5 days a week at work, so maybe I just used it too much.
    Also had the problem with both of them not connecting to my pc, plugging in the supplied cord would charge them, but I could not access the files on the memory cards.
     to Dobrescu George, I'm glad you have had good luck with the X5, that being said, I'm not impressed with the X5's I had, and am getting an Ibasso dx80 :)
     I did email Fiio, and the response I got back was:

    Dear user ,

    Thank you for your mail and support to FiiO.

    When did you buy the X5? It is X5 first gen or X5II? Are you capable to replace the battery yourself? It seems not only a battery issue only. You may take off the battery and collect the X5 to a power apply to see whether it can be turned on?

    Looking forward to your feedback.
    Have a nice day! 
    Best Regards,

    FiiO Customer Service
    1. Dobrescu George
      Hey there! 

      Have you tried getting in contact with FiiO support again? 

      I have used a FiiO X5 for a while now and it proved to be one of the best things that ever happened to me! 
      They should be able to help you sort things out! 
      Dobrescu George, Jan 22, 2017
  2. PinkyPowers
    The Long-Awaited Usurper - A Review of the FiiO X5 Classic
    Written by PinkyPowers
    Published Aug 10, 2015
    Pros - Sings like a champion. Handles like a schizophrenic gimp. Stole the physique of Vin Diesel.
    Cons - Scroll wheel, even on late models, is rather finicky. (not to be found in the body of the review... just 'cause)

    I’ve had my eyes peeled for a staunch enough system to replace my GalaxyS4>UAPP>OTG>Dragonfly1.2 mobile setup. While this package sounds amazing, it’s cumbersome and time-consuming to connect and get running. I have all my adapters and cables, along with the Dragonfly itself, in a leather pencil roll. To set it all up I must unroll the bundle, take the Dragonfly out of its sheath, remove the cap, pull out the cable I need for going mobile, connect everything, load up USB Audio Player Pro, and select an album to play. Oh, and headphones, of course. Gotta have that.



    All this can be accomplished in less than a minute. But in the doing, that time takes on a brutish quality. It’s a lot more work than it should be. I wanted something lighter and quicker, something self-contained, compact, and extremely easy to just pick up and go.

    Them who roam the lands of high-end audio call a contraption of that sort a “DAP”. Queer little buggers… these audiophiles.

    There are lots of options out there. Fortune placed a 2nd Generation FiiO X3 in my path at a reasonable mark-off. You can find that review on your own, if you fear what awaits you for not reading it. The X3ii did everything I could possibly want from a DAP, save one crucial mark: it did not match or surpass the Dragonfly in raw, unadulterated sound quality. It came close in some ways. The sound is so clean and lively, that after a week of not comparing it to the Dragonfly, I began to ponder why I should ever desire an upgrade.

    Then, when I listen to the Audioquest again, I am refreshed of its spaciousness, clarity, and refinement. After that, it’s tough to reconcile the disparity and convince oneself to settle.

    Perhaps a week and a half into owning the X3ii, I found a brand-new X5 Classic for $195. The taut, well-oiled reflexes of a degenerate sprang into action, and I pounced on the opportunity.

    Allow me to say, if you’ve spent the last month reading every review of the X3ii, X5 Classic, and X5ii, forming proper expectations is a cruel and befuddling exercise. Part of me thought this could be a monstrous upgrade. Another part feared it might weigh in just under the X3ii, and sound rather too dark as a bonus. Both extremes informed by stuff I’d read.

    My principle monitors for mobile and work listening were the fairly new AUDIO TECHNICA IM04 in-ear phones. Being on the warm side, I knew mingling with the X5 Classic might yield a very dark sound indeed.


    As it turns out, it does. But only on a few especially dark albums—like Lady Gaga’s Born This Way, or Dookie by Green Day, or Amy Winehouse’s Back to Black. Most everything else sounds marvelous. Using the ATH-IM03, which is a brighter, airier IEM, these darker tracks breathe again. The sonic signature is mildly warm, yet quite open and spacious. There is a rich, velvety smoothness to the music that favors slower acoustic pieces, yet somehow never falters on quick, complex tracks. Paired with a multi-driver earphone, you are treated to such immersive layering. The X5 is a clear, transparent, detail-oriented machine.

    I’ve coveted the aesthetics of the X5, even before I knew what it was. Again and again, as I read up on various products, I’d see a photo of this bold, almost brash, hunk of metal. I’d think, “That’s right and good, isn’t it? That’s what a DAP ought to look like.” I much prefer this design over the 2nd Gen FiiO players. While smarter, sleeker, and, functionally speaking, superior, they’ve killed something in the personality department. Also, on a carnal level, the fluidity of the scroll wheel of the X5 Classic promotes a greater number of erections than the cog-like workings of the newer players. There’s a luxuriousness upon fingering it which frightens me.

    When coupling this DAP with something larger, like the Sennheiser HD600, it holds up admirably. Setting the volume at 100/120 on High Gain, I reach a sufficient blast to meet the fundamental requirements of Metallica, the Black Album. These 300 Ohm headphones do not reach the same fidelity on the X5 as they do on my desktop amp. Then again, the Maverick Audio TubeMagic D1 Plus with the OPA627 upgrade is a hellcat. Nonetheless, fed by the X5, it sounds more or less badass.

    I don’t own a portable amp to which to chain my DAPs. Something like the E12 or the C5 is the antithesis of what I want from a portable unit. As I only take IEMs on the go, this is not a problem. But should I ever want to go mobile with a king-hell headset, the X5 will serve splendidly in a pinch.


    14 Ohms, 34 Ohms, 300 Ohms… all pair very well here. Even my 50 Ohm Klipsch X7i opens up like a prom date for the X5 Classic. It’s a privet agony, but the X7 has been relegated to backup duty in recent months. Once you go multi-driver, it’s impossible to willingly go back. Still, the X7 is the lightest, smallest, and most comfortable earphone I’ve ever tried. So they stick around, criminally underutilized, as my Podcast and Audiobook phones, played via the headphone-out of my Galaxy S4 (now S6). Heaven forbid if my IM03 were to go on a walkabout I could stride onward with the X5>X7i setup, head held high. They certainly make a handsome couple.


    So… the FiiO thrills on all of my equipment. But does it compete against that which it’s meant to replace? Well…

    The Dragonfly has a soundstage more-or-less equal to the X5, erring on the side of broader. There seems to be a greater degree of detail on the X5. It’s a close call, though. The Dragonfly sounds smoother, perhaps due to a combination of less detail and wider staging. Both sound very close to one another. I have trouble deciding which is darker and which is lighter. I believe the Dragonfly is a smidge brighter, if at all.

    It’s particularly difficult to decide which is better. Smoother speaks to refinement I’ve always felt, but in this case, the X5 makes up for it in detail, a natural rendering of space, and a lively sense of musicality. Switching back and forth between the two, neither emerges a clear winner. They share so much in common.

    Which makes this FiiO DAP a perfect replacement for the muddling mess of the Audioquest. I’ve been using the X5 Classic for weeks now, and have not once reckoned a lack in my listening sessions. This is what I had hoped the X3ii would sound like. Turns out my expectations were perverted by the lusty Dragonfly.

    If all you need is a thumb-sized DAC to plug into a PC or tablet, the Dragonfly 1.2 cannot be beat for the price. But if you want an all-in-one portable music player of extreme audio fidelity, the X5 Classic is where you start.

    I say “start”, because I’m nowhere near done yet. I still long to discover new levels of quality and refinement. But this will tide me over for a few months at least. It’s the beginning of August now. With my Christmas bonus I may give the Cayin N6 a try. See where that takes me.

    This is the perfect place to rest for a time. If I were unable to buy another piece of gear, it would not kill me. The X5>IM03 is unreasonably great and delivers immaculate pleasure to your ear-holes.


    1. View previous replies...
    2. PinkyPowers
      I know what you mean. Having JUST bought the X3ii, I was not planning on an immediate upgrade. A member here at Head-fi posted about an eBay auction for a brand new X5 for $225. When I clicked on the link, it had already dropped to $195 and I hit BUY NOW without a second's hesitation.

      As you are no doubt aware, that is an outstanding price. I haven't seen a brand new one going for anywhere near that since. Sorry.

      Got it from the eBay seller myluckydogs
      PinkyPowers, Aug 12, 2015
    3. 3 toes of fury
      Yo Pinky..thanks for the quick reply and info...i totally appreciate it.  And thanks again for such an outstanding review,  its write ups like yours which makes head-fi one of my favorite sites (and most dangerous sites for my wallet! he he he).
      Peace .n. Living in Stereo
      3 toes of fury, Aug 12, 2015
    4. PinkyPowers
      My pleasure, friend.
      PinkyPowers, Aug 12, 2015
  3. Currawong
    The FiiO X5 is a good value DAP if your needs aren't great and can be readily used as a transport or source.
    Written by Currawong
    Published May 3, 2015
    Pros - Inexpensive, great battery life, good with most IEMs. Can be used as a transport or with a separate amp for good results. Dual microSD card storage.
    Cons - Poor performance with full-sized headphones and needs a separate amp to work best with those. No touch-screen UI.
    Thanks to FiiO for the loaner unit.

    If there is a brand other than Apple that is more well-known at Head-Fi than FiiO I’d be very surprised.  A number of their products have become pretty much standard entry-level recommendations and their flagship amp, the E12 is a mere $129! However portable amps have been rapidly going out of fashion with the increasing number of DAPs, or Digital Audio Players on the market, itself a consequence of the increasing number of Android-based phones available, including inexpensive models in China, which in turn have provided much needed components to manufacturers of portable audio gear.
    While not Android-based DAPs in themselves, FiiO has gone with this trend and through something of a trial-by-fire as they worked on the software, developed the hugely successful X3. As their software has reached something resembling maturity, they came out with the larger X5. I became interested in the X5 because of the design and feature set and due to the positive impression I had of the sound at the e-earphone headphone festival in Tokyo in December 2013.

    I was lucky enough to get in the loaner tour for the X5 and hold onto a unit for a while to get the hang of its capabilities. Thanks to Joe Bloggs on Head-Fi for giving us this opportunity.
    Fiio_X5_DSC_6415.jpg   Fiio_X5_DSC_6397.jpg  
    It would not be unkind to describe the X5 as looking rather like a modern take on the original iPod. From the outside, the case is almost a work of art which manages to balance style with form and function. A physical scroll wheel and central button with 4 un-labelled buttons evenly arranged around it make up most of the front, and a small 400x360 pixel screen sits behind a wider piece of or plastic that, by default, is covered with a screen protector. The main volume controls sit on one side, two microSD cards slots and USB on the bottom and three different outputs on the top. The net result is attractive and reasonably functional, feels good in the hand and, with help from the quick-start guide in the box, doesn’t take long to get the hang of using.
    Next to the power button is the headphone socket, line out and a coaxial digital output for connecting to another DAC, for which a short cable is included. On the other end, astride the micro-USB socket are two micro USB slots, giving the potential for up to 256GB of storage (potentially costing more, I might add, than the X5 itself). While slower than a USB 3 reader, the X5 can be connected to a computer and the contents of the cards accessed in mass-storage mode or the X5 used as a DAC, where it will accept up to 192k and 24 bit input. The X5 will play the usual plethora of common file formats, including DSD, which is converts to PCM on the fly.
    Fiio_X5_DSC_7995.jpg   Fiio_X5_DSC_7997.jpg
    The attractive interface, if you don’t mind reading the tiny, and in the case of some of the indicators, faded writing. Indoors it wasn’t a problem for me, but outside in the sun, especially with reflections, like other DAPs became impossible to read. For those so inclined, a number of members of Head-Fi have hacked the firmware to produce their own versions*. Despite being small, the interface is very quick. Scrolling fairly fast even though a large number of albums there are no delays or even stutter when turning the wheel at a moderate speed, though over two rotations per second it starts to struggle. Any delays come from having to repeatedly press and scroll through the menus. If you have as I do a very full 64 GB card, getting to an album in folder view half way down (or up, as scrolling jumps from beginning to end if done backwards and vice-versa) can take quite a while. The fastest way to drill down is via genre, if your music is tagged sufficiently well and you have a variety, followed by Album and Artist by picking whichever is closer to A or Z in the list.
    Fiio_X5_DSCF1637.jpg   Fiio_X5_DSCF1641.jpg   Fiio_X5_DSCF1644.jpg
    If you’re thinking now “Why not just load on some playlists?” you’ll be disappointed to know that one major omission is support for M3U playlists. In the Chinese market, according to FiiO, playlists aren’t a big thing. If you wish to use playlists, you have to manually create them inside the X5 by playing the song and adding it using the quick menu button to a playlist, which cannot be re-named from the default “Playlist 1/2/3/4/etc.” Similarly, while there is an equaliser with a number of presets available, the lack of a touch screen means that the custom EQ needs to be set via a series of scroll, press-and-scroll motions, which can be somewhat tiresome. 
    The good news is, however, the battery life. When not playing music, even left switched on, the X5 takes days, if not over a week, to drain the battery. Switched off the battery didn’t deplete even when left for a month unused. Playback time for CD quality files is quite long, over 10 hours according to the specifications.
    The volume control has a very useful 120 positions, at least so for IEMs, with a setting for the default power-on volume level. It can be controlled using the side buttons, or using the scroll wheel after pressing one of the side buttons beforehand. Which buttons will still work after the screen is off/locked can also be controlled via settings, with three options for side volume buttons only, side buttons and play/pause button, or the previous setting plus forward/back buttons. While convenient, the idle power off setting, if on, is limited to only 1 to 8 minutes, though the sleep timer can be set to up to 2 hours.
    Other than that, the X5 has a good number of settings for everything from balance and playback mode to being able to set whether songs are displayed by file name or title and whether or not to go to the last played song on startup.
    What has now become something of a reference album with headphones, I put on Amber Rubarth’s Sessions from the 17th Ward. Switching between DAPs and IEMs it would become pretty quickly apparent which equipment was more or less capable of delivering the fine details buried in the tracks, from the birds tweeting outside to traffic noise and subtle movements of the musicians.  The IEMs I settled on for comparing, all high-quality, if varying in degree, were the FitEar Parterres, Ultimate Ears Reference Monitors (UERMs for short) and JHAudio Layla universals.  While the Parterres didn’t reveal much difference between the X5 and my AK240 (single-ended output), as I stepped up to the other two, especially since the UERMs and Laylas have balanced cables, the differences became apparent. My first impression with the various IEMs was of a slightly warm, but not ultra-revealing presentation.  Out-and-about, the X5/Paterre combination made for a very enjoyable listen, especially given the slightly lighter-weight frequency response of the Parterres. The Laylas, on the other hand, just revealed how dull and one-note the X5 was with acoustic music, the bass when attempting to push so many drivers also somewhat boomy and loose.
    While I felt that the X5 does an adequate job with IEMs, with full-sized headphones it clearly had trouble, despite the nice-sounding numbers of <115dB S/N ratio and <75 Ohms crosstalk shown in the specifications. Plugging in Sennheiser HD-800s and other high-impedance headphones resulted in the music sounding like it was coming from a blob in the middle, most noticeable where I knew the music should have a wide soundstage. My more basic Audio Technica ESW9LTDs were more along its capability level. FiiO’s E12 amp, designed for full-sized headphones, is the same size as the X5 and FiiO provides a kit allowing them to be joined together. While I didn’t have one on hand, I used my Headamp Pico Power instead, which was clearly far more capable with full-sized headphones. The combination with either amp is still cheaper than other DAP options that do a decent job driving full-sized headphones that I’ve tested, such as the Calyx M. The only rivals that I can think of would be the iBasso DX50 and DX90 which I haven’t had the chance to test.
    For further discussion, check out my DAP-off thread here: http://www.head-fi.org/t/714374/
      Hawaiibadboy and Vartan like this.
    1. View previous replies...
    2. Hawaiibadboy
      I do have to use mine with a Cayin C5 for over ears myself but the customization of themes is amazingly easy and makes it a very personal experience in the interactive sense. Thanks for linking to the Mod thread. It's a great sell point that FiiO never mentions itself.
      Hawaiibadboy, May 3, 2015
    3. Currawong
      @AmberOzL: that should have been 3.5 stars. I thought that's what I clicked. :)
      Currawong, May 3, 2015
    4. twister6
      Hi Amos, glad you got a chance to test and to review X5.  A lot of good points in your review, including that it's best used with external portable amp (E12A pair up is excellent).  Btw, X5 2nd gen supposed to be released very soon, and their first android-based touch-screen X7 is not too far away.  FiiO has been on a "smartphone" release cycle, and keeps improving both hw/fw with every new release.
      twister6, May 3, 2015
  4. HUM24H
    Fabulous DAP
    Written by HUM24H
    Published Apr 4, 2015
    Pros - Tight & Clear Bass, Very clear & articulate midrange, detail high end, dual microsd slots, build
    Cons - UI, Costs
    Fiio X5 Review
    Fiio as company in the Audio Market is very well known for bringing Audio equipment to the mainstream market that not only sounds good and looks good but priced good. There was a point in time where we would’ve turned our back on Chinese Audio Companies but recently we have been accepting them and they have been outdoing their competition with quite a few successful products. Over the years Fiio has made a name for itself with portable headphone amplifiers and dacs but in 2013 the company decided to make a move into the world of Digital Audio Players or DAPs. They did this by giving us the successful Fiio X3, while it had an old school look it provided a great sounding portable music player that could play almost any file format at a great price. But being Fiio they always like the one up themselves where they can, so in the beginning of 2014 we saw the fabulous Fiio X5 come to market which aimed itself in the Mid-Fi to High-End Market by coming in at a price of £450.00 (RRP) and here it saw competition from the likes of iBasso, Colorfly and Astell & Kern who are very big names in this portable audio market. So did it deliver? Yes it did!
    Exterior Design
    The exterior of the Fiio X5 is a well made and solid design, the entire chassis and housing has been constructed from Metal with the buttons being constructed of Metal. The top output ports are gold plated, this is to ensure a more durable connector and overall increase lifespan. There is a myth that gold plating does improve sound but so far this hasn’t been confirmed and the original use of gold plating on electrical connectors such as 3.5mm connectors and usb connectors is to get a better contact between the two connectors and improve durable which in turn improved the life span of the connector. Next we have the big design choice which sticks out like a sore thumb, this is the mechanical scroll wheel. This is reminiscent of the older iPods which used this to control the device but where the Fiio differs from the iPod is by using a mechanical scroll wheel which does feel better but unfortunately there are some problems where by the scroll wheel can be a bit loose and it can take time to respond in some cases. The IPS Screen is a very nice touch, providing very nice colour and a good resolution with Text and album Artwork looking very good on it. The Dual MicroSD Cards is another very good addition, as with most Music Fans their libraries will be huge especially if they are in FLAC or Hi-Res so therefore having dual MicroSD Card Slots means we get up to 256GB of Storage and I’m sure Fiio will allow us to expand further when larger MicroSD Cards become available, but the only problem here is the covers for the MicroSD Slots are quite difficult to remove and to be far I don’t see why Fiio just didn’t use a sliding door like Astell & Kern. Overall the exterior is very well made and mostly designed with thought but in some cases they could of done better.
    Internal Hardware
    Internally the Fiio X5 also has us covered using a PCM1792 DAC for the digital conversion, then we have 4 op-amps which are OPA1612 handling Volt Amp, I/V Conversion & Low-Pass Filtering. Then to finish it off we have two headphone output chips which are LMH6643 which hand the Current Amplification and the Headphone Output. The PCM1792 is a superior DAC to that found the original X3 which was a Wolfson DAC, WM8740SEDS. Now the little brother, Fiio X1, uses another PCM DAC which is the PCM5142 and the new X3 uses a Cirrus Logic DAC which is the CS4398 but in the case of the X3 it uses the same OPA1612 as the X5 but only two which handle Volt Amp and Low-Pass Filtering and then a single LMH6643 for Current Amplification and Headphone Output, so where the X5 can split the output into Left & Right the new X3 does them both on a single chip. The hardware found in the X5 is very good, but at this point I can’t compare it to the X1 or X3 to see how this hardware configuration compares to them. Now comparing the hardware of the X5 to the iPod Video 5g and Note 4, well the iPod uses a Wolfson Dac which is the WM8758 DAC which in itself is a pretty great DAC. Now the Note 4, well not sure we know what it is cause as far as I am aware I can’t seem to find out what it is so if people know then please comment but we do know that it will decode 24-Bit/192Khz Music Files so it’s not a slouch.
    User Experience (UI)
    The UI is another section that needs to be done right, as if the UI is poor then users will not want to use it. Well I am partly happy to say it’s good, ish! Now the good thing is that once your library is updated, the X5 is able to successfully compile your music by Artist and Album without issues plus navigating the UI is fast thanks to the Dual-Core Processor found inside the X5. But for me I feel the UI could've been designed a lot better, to me it doesn’t seem to well thought out and compared to the likes of the iPod it does seem old fashioned. Plus navigating and finding your way around can be difficult at first but you do get used to it. Overall I feel that the UI is ok but not great and could’ve been done a lot better.
    Now let us get to the sound, I shall try to explain as best I can the sound I can hear coming from the X5 but please do remember that this is my own personal feelings of how I hear the sound. Everyones ears are different!
    So the bass is by no means overpowering and by now means fitting for real bass heads, there is a bass boost but I don’t use EQ so the out of the box SQ is not bass head ready. However the bass is strong, tight and clear, there is no sense of it being weak nor withdrawn. The bass has great presence without overpowering the rest of the frequency range. It has very good separation, by being very cable of separating Kick Drums from Bass Guitars makes for a very good low end experience.

    The mid range for me is great, its neutral and is always there, it just never goes away! Which is a great thing, the one I like is hearing Vocals which falls into this range so having the mid range clear, articulate and neutral means it never gets overpowered nor gets put aside, for Metal/Rock/Rap/Pop or anything with vocals this is something I always want from my Audio equipment.
    This is where I feel the detail of the X5 gets into its own, the highs are detailed and extend very well. They can sound a bit bright but overall I love it, hearing cymbals crash and high guitar notes clear without distortion makes for a very pleasing experience.
    If you pair the X5 with a headphone that can separate well then the X5 will compliment it by separating instruments very well. It almost feels as if I can sense the silent space between the instruments and for that really gives great airiness to the sound. This provides a great soundstage as well, it doesn’t feel compressed nor claustrophobic. Remember “The music is the silence between the notes” and does it ring true when the song is separated well.
    Overall the sound quality is neutral with each section of the audio spectrum well presented and not overpowering each other, each range is allowed its space to perform without the other ranges coming in its way. The treble can sound a little bright or harsh but this is very dependent on the track and how the track is mastered. If I was to sum up the way the X5 sounds, its that the Music drives the X5 not the X5 driving the Music.
    The following comparisons were done using the following albums:
    Killswitch Engage - Disarm The Decent
    AC/DC - Back In Black
    Warpaint - Warpaint
    Slash - Slash
    I know I specifically chose these albums mainly because Disarm The Decent and Warpaint can suffer from a too much low end and muddy sound, this would allow me to see how each player would handle these kind of tracks. Then using the AC/DC Album & Slash Album allows me to see how well each player separates the sound and how clear the SQ can be. So while it may seem unfair using partly poorly mastered albums it helps to see how each player handles them, as remember not all albums are mastered perfectly.
    Compared to iPod Video:
    The first things I notice is how the bass on the iPod does become a little boomy when compared to the X5 especially because of the Bass Guitar and Low Electric Guitar notes, however the X5 also suffers a little bit a boomy bass due to the track but not as much as the iPod, with the iPod I feel the slightly worse bass management on the iPod does affect the other ranges where the X5 has better bass management allowing the other ranges to work better. The next thing is the kick drum which sounds a little weaker on the iPod compared to the bigger presence it has on the X5. The vocals also sound a little bit more withdrawn on the iPod than the X5, whether than means the X5 is more forward in the midrange than the iPod who knows but having the vocals sound a little bit withdrawn is quite annoying. Plus I sense a lot more airiness and spaciousness on the X5 than the iPod. By no means does the iPod do poorly, in fact it does a good job and performs well but the X5 just out does it in almost all aspects. Would I say upgrade to the X5 from the iPod, well for me the slightly boomier bass from the iPod and slightly weaker midrange makes me want the X5 a lot more.
    Compared to Samsung Note 4:
    The Note 4 does have a clearer sound than the iPod and better management of its bass, the separation of the Note 4 is actually quite good and overall the SQ is quite neutral and similar to the X5 but again I feel the X5 just has a little bit better clarity and spaciousness. But by no means does the X5 get a clean whitewash over the Note 4, as on it’s own with and without the Fiio E11K which when added to the Note 4 makes the SQ a little thicker and deeper adding nicely to the clear SQ. So while I recommend the X5 over the iPod Video, if you already own a Note 4 have a go at pairing it with a Fiio AMP like the E11K or E12 and you could even pair it with an AMP/DAC like the Oppo HA-2 if you want to.
    So while I recommend the X5 over the iPod and mostly over the Note 4 but with the Note 4 I would say have a go with some portable AMP/DACs and see how it goes as you may be surprised. I still feel for the price of the X5 + MicroSD Cards, I would highly say have an audition of the Fiio X1 and Fiio X3K to see how they sound compared to your current setup and I will only really recommend the Fiio X5 for those who really want the top end from Fiio, like me!
    Final Thoughts
    Well this has gone on for a while! Please do remember this is all my own opinions and your own experience can differ for the better or the worse. For me the X5 serves as a great foundation to build upon with better headphones and IEMs, it allows me to have a great source to which I can then plug in some great headphones. But like a lot of things I own, I don’t always recommend it even though I love it a lot and the reason being because when comparing to the Note 4 I was surprised how the Note 4 was able to keep up mostly with clarity and spaciousness to the X5, it really shows that if you try it out with some portable AMP/DACs it can shine. And with the X1 and X3K below it, it makes much more sense for people to try those out first as considering the Fiio X3K uses a similar circuit to the X5.
    1. Sefelt103
      Excellent review. Interesting comparison with Apple iPod 5G. The iPod's bass was always the problem, slighly lacking in level and equalised in some manner. How would you compare the UI of the iPod with the X5 ? For thise of us in the UK the RRP is almost double what people in the rest of the world pay. Considering there is the additional storage cost this makes this player quite expensive and puts into the orbit of players like the QLS QA360.
      Sefelt103, Apr 5, 2015
    2. HUM24H
      I prefer the UI on the iPod, the UI on the X5 is ok but like I said could've been done better. 
      HUM24H, Apr 5, 2015
  5. Hawaiibadboy
    Great 4 modding
    Written by Hawaiibadboy
    Published Feb 21, 2015
    Pros - Modifiable User interface
    Cons - EQ, library navigation,
    Theme in video     https://www.dropbox.com/s/3r8b8wlkcyiw4hn/x5.fw?dl=0
    This is an updated video review and it is highly suggested you try and enjoy the multiple custom options this device offers.
    I cannot and did not use the default theme as i have never seen it. That's how easy it is to customize this device or use another persons theme.
    If you have not updated to FW 2.5 it is strongly advised.

      Vartan likes this.
  6. JoeDoe
    Fiio X5: Top-tier Sound for the Rest of Us
    Written by JoeDoe
    Published Sep 27, 2014
    Pros - Sound Quality, Looks, Price/Value, Storage, Versatility
    Cons - UI, Wheel
    The X5 from Fiio. Where to begin...
    Perhaps I'll start with dual-CPU processing power... or maybe the dual TF card slots... or perhaps USB DAC functionality... then again how about the exceptionally black background...
    So many options. You know what? I'll make your life easier. Since every other review is pretty dang thorough, I'll just include the highlights and then my personal impressions.
    The Hits 
    1. Support for every lossless format under the Sun
    2. USB DAC capability
    3. Two TF-card slots (up to 256 GB!)
    4. Exceptional firmware/UI development that continues to improve
    The Misses
    1. The click wheel implementation
    2. Non-removable battery
    My Thoughts
    To give you an idea of where I'm coming from, my head-fi DAP history has included a plethora of iPods, a sample of Sansas, a cache of Colorfly, a basket of iBassos, and a few Fiios. Some like the iPods, C3, and DX50 were used with additional amps & DACs, while the X3, DX90, and now X5, have been standalones. 
    The X5 is the one I've decided to keep and here are the reasons why:
    Duh. This whole journey has been a pursuit of better sound without sacrificing much else. The X5 does it right. It's a noticeable step up from the iPods, Sansas, and Colorfly so I won't reference those.
    In comparison to its younger sibling, the X3, the presentation is more neutral, with just a dash of warmth in the lower mids. Both have the Fiio sound, but to me, the X3 is the obsessed-with-being-cool younger brother, and the X5 is more sophisticated, eternal-bachelor uncle. Just more refined, clear, authoritative sound. Since it's often a subject of contention, I'll cast my vote confidently for the X5 over the DX90. It's got a more organic (less digital) sound and comes at a substantially lower price. 
    Mid- and sub-bass are both very textured and well-balanced. From Paul's upright to Bassnectar's bass cannons, I've never once wanted more. This is definitely a pro for the X5 over the DX90. The 90's bass is heard. The X5's is felt. Which, if you ask me, is better. I've never been to a concert or venue where, when it was time, I didn't feel the bass, whether it be from a drum or an instrument. 
    Vocals and instruments presented in the midrange are in a word: rich. From the distortion in Jimi's electric to the rasp in Norah's voice, I've always felt that the X5 does the mids better than is let on. Often in DAP-world, we judge by extremes. Depth of soundstage. Low-listening noise. Extreme upper and lower-end frequencies. Sometimes we forget about the middle. Well, have no fear. I did not forget, and neither did the good people over at Fiio. The X5 gives them just like they were recorded. 
    The X5's upper end is solid. It's not as spacious as the DX90, but it's certainly close. It extends farther than the X3, and offers more detail than the DX50. Thanks to the exceptionally noiseless background, all the details you only hear up top are easy to discern. Things like Joe's fingers sliding on guitar strings, Adele's breathing, and Neil's cymbal rolls are very detailed and lifelike. In my experience, these kinds of things are lost in live recordings with most DAPs. They just don't have the resolution capability to make instruments recorded live sound like it. Luckily for us, the X5 does.
    All in all, the X5 offers a complete audio experience that doesn't leave this listener wanting anything. In a world where DAP to DAC to AMP to headphone pairings are all the rage, this is quite a feat if you ask me!
    With regards to the X5's user experience, we've been presented with something original (always scary) yet very capable. Physical buttons require a little getting used to, but they follow a reasonable navigational scheme. I also appreciate the thought that has gone into making this player one-handed and non-visual operational. Being able to choose which buttons function when the screen is off is a nice touch. I can operate all audio functions without seeing the player!
    The UI has a pretty short learning curve, which is certainly appreciated. Honestly, no matter how good the sound is, a bad UI can be a dealbreaker. Fiio's folder-based UI is easy enough to navigate and adjusting player and audio settings like gain, EQ, sleep, and card-scanning are reasonably intuitive. Heck, I like the look of the nav screen with it's circular design. Even the volume adjustment is cool. Unfortunately, I can't stop here though...
    The qualms I have with the UI right now are that 1. the playlist support is clunky at best. 2. the Verdana-style font with now-playing information is a little annoying and 3. the click wheel. Why oh why would you try to make a different click wheel the the most popular portable player of all-time? That's asking for it. The X5's wheel works just fine, but it's mechanical design (as opposed to the iPod's electronic) drops the ball in two ways. First, it has as limited scroll speed - super annoying for those of us with large libraries. Second, one click of the wheel does not equal one move on-screen. Sometimes it does and then sometimes it doesn't. This makes for a lot of missed selections. 
    Even though I don't use them much, there are other functions that the X5 offers which should satisfy most users. First, it's USB DAC capability is quite nice. It offers some seriously quality sound for those of us who are doing most of our listening through a laptop or portable rig. It's coax and line out are also very convenient. The line-out is one of the cleanest I've ever heard!
    Finally, I should mention that the driving power of the X5 is excellent. I've yet to use a headphone that made it feel insufficient. From the 215s to the KSC75s to the PS500s to the ZMFs, the X5 drives everything I've thrown at it with authority. This is great not only from an SQ standpoint, but also from a convenience factor: I don't need to look for an additional amp! No more double-stacking! Woohoo!
    In closing, the X5 from Fiio bests most of the other DAPs in and (obviously) below it's price bracket in almost every category. I can't compare it to the offerings from A&K or the brick of a player that the DX100 is, but I can assure you that it leads the race in my experience, for sub-$500 players. From it's excellent sound quality (I don't remember the last time I listened so exclusively to my portable device), to it's "extras" like dual-TF slots and USB DAC capability, to it's authoritative amplification, this DAP has proven it's worth time and time again. If you want an all-inclusive solution to hear your music more clearly and enjoyably when you're on the go, look no further than the Fiio X5. 
      Brooko, 3ternalDr4gon and EfrenHF like this.
    1. View previous replies...
    2. Subseastu
      does anyone have any idea if this is a marked step up in SQ over a cowon J3?
      Subseastu, Sep 28, 2014
    3. kenz
      It is a very clear step above the Cowon J3.
      In fact, the Fiio X1 is a step up from the Cowon J3;
      Great review. 
      The X5 is not perfect, but it does so many things right that you'll forgive the small quirks.
      For its sound quality, performance and price, it is hard to find any credible competition in its category or above its price point.
      kenz, Sep 28, 2014
    4. Subseastu
      Thanks Kenz, I was a bit worried that its wasnt really a significant step up. I may hold out for the X7 though
      Subseastu, Sep 28, 2014
  7. Cachicamo
    My new everyday DAP (and most other moments as well)
    Written by Cachicamo
    Published Jul 9, 2014
    Pros - Sound quality, build quality, options
    Cons - File transfer speed, navigation memory
    To be able to value my review I think it is important to mention some things about my preferences and experience with audio equipment and writing reviews. This is my first review for audio gear and I got involved in the audiophile world about 5 years ago when I bought my first earphone upgrade with the Ultimate Ears Superfi 5. Later I got the triple fi 10, UE900, Unique Melody Miracle and Cosmic Ears CE4E. I’ve been listening to my iPod with a Meier Audio 2Stepdance and was always very happy with this gear. I’ve tried the Colorfly C4, Fostex HP-P1, Fiio X3, Ibasso DX50 and DX100, but neither of these convinced me enough to trade in my iPod combo. Not that they weren’t good, but the upgrade wasn’t worth the money in my opinion. I have to admit though that it’s been a while since I listened to the other players. I would very much try the AK240 and compare it to the X5 but it is and will be beyond my budget.
    I am a detail freak. I like to hear everything in a song and I don’t like to use eq, because I’d like to hear the music the way the artist intended it to sound.
    I have tested the X5 with the Cosmic Ears CE4E.
    To my ears the sound can be described as very detailed, spacey and without coloring. I mean that neither the bass nor the highs are emphasized, well-balanced that is.
    I decided to give you my impressions based on some songs that I know very well and that I always use as a reference when I listen to new gear. I don’t care a lot about UI and I think the build quality has been discussed enough so I’ll skip that and I am satisfied with it anyway. The only thing I would have liked is that you don’t lose your place in the folder when you go from the main menu back to the ‘now playing’ song. You have to browse to the song folder again from the main menu. Fiio is constantly updating the firmware so this might not be an issue in the future. One of the reasons I was willing to try the X5 was the possibility to have up to 256 GB of storage. I would very much like to express my appreciation to the Fiio people who show that they are really committed to make a product that meets the wishes of the customers to whom they are actually listening! I have no relation with Fiio besides being a customer.
    I listened to CD quality songs and HD songs, but unfortunately I couldn’t hear a significant difference. So besides the Beatles remasters at 24bit I used 16 bit/44khz files.
    I Am the Walrus              The Beatles
    I always found the Beatles recordings sound a bit amateurish and not very transparent, but when I listened to the 24bit remasters with the X5 it sounded very transparent and I heard instruments I hadn’t noticed before, for example I never noticed that there was an electric guitar playing along with the electric piano in the verse part. The strings are very pronounced where you can hear the overtones and the bow touching the strings. Even when there are other instruments playing at the same time.
    Chuck E’s in Love            Rickie Lee Jones
    I’ve always loved the production of this song. Really clear and you could always hear all of the instruments. The X5 didn’t reveal things that I hadn’t heard before, but some instruments are a bit more refined. For example the kick drum isn’t just like a low bump, but it has more details, as if you were standing next to the drum kit when you can even feel the kick.
    Getting Better                 The Beatles
    Like I Am the Walrus, more details and a wider soundstage. A silly detail that caught my attention was the click (a guitar being turned on) you hear when the ‘high’ guitar part (the one the song starts with) comes back in the chorus. These kinds of details, however not musical, make me happy.
    Dogs                                     Pink Floyd
    I have been listening to this song since I bought the album in 1985. There are acoustic guitars almost throughout the whole song (except the electronic intermezzo that I used to skip…). When the acoustic guitars fade in in the beginning of the song they sound really dry and natural and you can even hear the pick touching the strings, wonderful! Until I Iistened to the song with the X5/CE4E I didn’t really notice the acoustic guitars in the part of the guitar solo just before the lines ‘…And when you lose control..’ They are really present and detailed where they were masked by the electric piano and bass listening to it with my old gear.
    Babylon Sisters                               Steely Dan
    I find the production of this song already very pristine, so transparent, but I was surprised that it could sound even more transparent. The best way I can describe it is that it made me feel as if I was ‘in’ the song. I could ‘feel’ the music like you feel a kick drum when you are standing next to it.
    It seems to me that well produced music sounds even better with the X5/CE4 combination, but that it doesn’t improve bad recordings. If tried songs that I thing lack dynamics and they are not sounding better with the X5. For example While You See a Chance from Steve Winwood. Although I love this song it has always sounded ‘thin’ to me and it still does with the X5/CE4, even the 2012 remaster. Matter of production I guess.
    For my needs the X5 is a wonderful player. It has been a very big upgrade from the iPod and although I haven’t tested it with headphones of lesser quality I thing you need a good pair of IEM’s to fully appreciate the power of the X5 (as I have done with the Cosmic Ears CE4). I participated in the European tour of the demo unit, but I had ordered an X5 even before I forwarded the demo unit as I didn’t want to miss that listening pleasure! I hope I have given you a useful impression of the device. Any questions? Please let me know. 
    1. View previous replies...
    2. Cachicamo
      For now it's the X5. Though I still like the iPod for it's ease of use and the fact I can use it in my car...
      Cachicamo, Jul 10, 2014
    3. Cachicamo
      For now it's the X5. Though I still like the iPod for it's ease of use and the fact I can use it in my car...
      Cachicamo, Jul 10, 2014
    4. DigitalGrounder
      Great review I might need to get an x5 of my own
      DigitalGrounder, Jul 14, 2014
  8. DVass13
    Good improvement over the X3
    Written by DVass13
    Published Jun 21, 2014
    Pros - Huge variety of file support including DSD, solid feel, included accessories, doubles as standalone DAC
    Cons - Scroll wheel needs refinement, UI could use some improvement as well
    I am writing this review about a tour unit that I received from Fiio for a 10 day trial. I currently own the Fiio X3 and use it as my portable DAP as well as my DAC with my home setup. I tested this tour unit as a portable DAP by itself, as a portable DAP combined with the Fiio E12, and as a DAC with my desktop and Schiit Mjolnir. I listened to these setups with Sennheiser HD 598s, HD 700s, and Audeze LCD-Xs (as well as some Skullcandy "The Fit" earbuds for some train rides through Chicago).
    Upon receiving the X5, I was happy to see the numerous accessories included with the unit:
    - Fiio X5 unit with screen protector applied
    - Two extra screen protectors
    - Silicone case
    - USB Cable
    - 3.5mm to RCA digital coax adapter
    - Three 3.5mm dust covers for the 3.5mm ports
    - Micro USB card reader
    - User manual and HD Tracks coupon code
    My X3 came with a plethora of accessories as well, so it was nice to see Fiio continue this very much appreciated trend.
    Initial Impressions
    Holding the X5 for the first time I noticed that it felt very solid. It has a good weight, but is not necessarily heavy. It seems very well built and like it could stand quite a beating with the exception of the scroll wheel. The wheel seems a bit loose and that it would be the 'life-limiting' feature of the unit. Aside from the wheel, the buttons feel solid and durable. The input/output jacks seem well laid out as well. I'm happy to see the line out jack is at the top of the unit. This makes it easier to pair the X5 with the E12. The line out is on the bottom of the X3 so the E13 must be turned upside down to use one of the short line out cables. One thing that seems a bit odd to me is the placement of the four buttons surrounding the scroll wheel. Perhaps it's my experience with iPods that makes me want to use the top, bottom, left, right locations for moving through the menus, but it seems a bit more natural than the current layout of the X5. I guess the buttons fit the given space, though. The only other feature that seemed a bit of a hassle were the microSD card slot covers. They were a bit difficult to open and I had to resort to the tip of a mechanical pencil to pry them open. This isn't a huge issue, though, since I wouldn't be accessing the cards on a frequent basis.
    Standalone DAP
    I found the X5 very useful as a standalone DAP. I could see it very easily replacing my X3. I really like the idea of dual microSD slots as my music library is ever-growing and high-res files take up quite a bit of space. The X5 was able to drive all three of my headphones to a good listening volume. Unfortunately, I didn't do a proper back-to-back comparison between the X3 and X5 from an audio standpoint as I spent most of my time with the X5 on a trip to Chicago and did not want to bring both DAPs. I used my sh***y Skullcandy earbuds during this trip and was actually surprised at how good the music sounded out of such a low-quality earbud. For my few days back home listening to the X5 as just a DAP, I noticed no distortion or coloration of the music, but did notice that the X5, like the X3, did not have enough power by itself to bring the LCD-Xs to their full potential - not that I would use them as a portable headphone anyway. 
    X5 + E12
    After returning from Chicago, I tried out the X5 with the E12 for a brief period (only an hour or two to listen to some of my favorite songs). I noticed that the E12 gave some extra oomph to the X5 and increased the soundstage of my 598s and 700s. Pairing the combination with the LCD-X left them sounding a bit veiled (if that's the right word), though not as much so as with the X5 alone. Again, I wouldn't plan on using this setup with my LCD-Xs as a portable rig, so no worries there. I would be perfectly happy with the X5 --> E12 --> 598s.
    X5 as a DAC
    During my remaining two days with the X5 I used it as a DAC. My setup was high-res (FLAC and DSD files) to the X5 and fed via line out to the Mjolnir. I listened to this with my HD700s and LCD-Xs through balanced cables and was very happy to see that I could finally listen to some of the DSD files that I hadn't been able to listen to previously. (The X3 is now capable of playing DSD files via firmware update released since my time with the X5) I was very impressed with the clarity of the X5 and found myself sitting for hours on end into the wee hours of the morning absorbed in my music. Using the X5 as a DAC brought forth the best of both worlds. It gave me the high-res DAC capability of the X5 and the powerful amplification of the Mjolnir. The extra power from the Mjolnir really helped to open up my LCD-Xs and bring them closer to their full potential. Even though they are efficient headphones and the X5 alone can bring them to a comfortable (or more) listening level, the extra power from a separate amp is a noticeable improvement. 
    Final Thoughts
    As a result of my demo of the X5, I do plan to try to sell my X3 and upgrade to the X5. I've heard Fiio plans to release another DAP or two in the near future and would be very interested in demo-ing those as well. For now, though, I see reason to upgrade from the X3 to the X5. Even if there was no change in audio quality between the two, the additional storage capability of the X5 coupled with its more user-friendly layout (still not perfect) is reason enough for me to make the move. A $350 price tag for a device that serves both as a standalone portable DAP and as a DAC for my home setup that is DSD capable seems like a steal to me. Overall, I liked the X5 very much and hope to see some of the few cons worked out in the upcoming products.
    1. chengsta
      great review.  Had my x5 for several months now, and I love it alot more than my x3.  The line out is just superb.
      chengsta, Jun 29, 2014
  9. musikaladin
    Nice product, definitely worth the money!
    Written by musikaladin
    Published May 18, 2014
    Pros - Sound quality
    Cons - Some minor issues with the volume setting in relation to the lockscreen
    I owned the X5 since 3 weeks when I wrote this mini-review, and there is absolutely not regret in relation to that purchase..
    The design is not really my piece of cake, but this is not supposed to be a judgement, because I can imagine that others will especially like the X5 for it's looks.
    The sound is as good as you could expect it from a portable unit in that Price range. The sound stage is stable, the background as dark as I could wish, and there is no recognizable coloration and distortion. Just make sure your headphone is on the rather higher-efficiency side. So in-ears as i.e. my Miles Davis Trumpet obviously go very well, but also full-size cans as my AH-D7100 sound really great.
    More about my impressions, especially concerning the user interface in relation to the volume settings and lockscreen here.
    1. GL1TCH3D
      Thanks for your review!
      GL1TCH3D, May 18, 2014
    2. musikaladin
      Welcome. I know, that was a rather short review, but that's pretty much all what is relevant to me...
      musikaladin, May 18, 2014
  10. wormsdriver
    My long overdue review of the Fiio X5!
    Written by wormsdriver
    Published May 3, 2014
    Pros - Sound quality, black background, build quality, long list of features
    Cons - *most of my gripes with the X5, I believe, have been taken care of with the newest firmware*

    Fiio has become a well known brand in the last few years by people in this hobby due to their very affordable and well built products. Pretty much everything you need for your portable set up they've made available for a great  price and solid performance on top of that! 
    From interconnects, line-out docks for idevices, iem cables, amplifiers and DAC/Amp combos, and most recently their very own Fiio X3 DAP. The follow up to the Fiio X3 is this little device I have here which I am about to review...
    Before I go any further, I would like to give a big thank you to Fiio and special thanks to Head-fi member Joe Bloggs  for letting me get a sneak peak of their newest addition to their product  catalog, Ladies and Gents... the Fiio X5!

    For the record, I have no affiliation with Fiio and this review unit is and will remain the property of Fiio as it is only on loan to me for ten days for this review.
    As I mentioned before, this is a preview sample of the X5 that is on loan to me from Fiio, which has not been released yet in North America, so packaging, accessories and/or even the X5 itself might slightly differ from the final release version that will be due out very soon...

    The X5 comes in an attractive retail box which is overall black in color with some red overtones.
    After opening the retail box you are greeted by a textured black cardboard box that contains the X5 and other  goodies, which include:
     1. Fiio X5 unit
     2. Black silicone case
     3. USB Cable
     4. Micro USB card reader
     5. 3.5mm to RCA digital coax adapter
     6. Two extra LCD screen protectors
     7. Three 3.5mm dust covers for your 3.5mm ports
     8. User manual, and other paperwork
     *MISSING - The OTG cable was not included in my review sample, but will be provided in the retail version*
    Build Quality:
    I must say I am impressed with this unit. It is very well built, nothing about it seems cheap and it has a very nice solid heft to it. The whole body seems to be made of machined aluminum. The power button, volume keys, the "select" button that is in the middle of the scroll wheel and the four buttons on the front of the unit are also made of metal. There are three 3.5mm jacks on the top side of the unit that are of excellent quality reminiscent of my Meier  Audio Corda Quickstep amp.

    The scroll wheel reminds me of a sansa player I had some time ago, it has a rubber texture on it and quite frankly I don't see it being an issue, or at least not an issue for a good few years of heavy use, imo.
    Operating the Unit:
    Being the manly man that I am, I did not read the user manual and dug right into the X5.
    I found the X5 to be just as intuitive as I have found any other unit that I've own in the present/past. Your basic operations are easy to figure out in no time, while other features will come out as you spend a bit more time with  the player.

    As you all know, at this point in time there are many excellent and in depth reviews about the Fiio X5, so instead of  going on and on about every single detail when it comes to operating the unit I will refer you to the User Manual  which can be downloaded through Fiio here:   (http://fiio.com.cn/support/download.aspx ) and does an excellent job at  explaning how to operate the X5.
    The X5 is packed with features that make it extremely attractive if you are in the market for a Hi-res DAP, in my opinion. Not only is it able to play a large array of Lossless and lossy formats (DSD decoding will also be available at a later date through a firmware update), but it is also able to natively play Hi-Res content of up to 192k/24Bit!  The X5 can also be used as an Asynchronous USB DAC from your computer which is a great feature!
    On the hardware side of things, you have two micro sd card slots at the bottom of the unit that can handle the newly released 128gb micro sd cards (must be formatted to Fat32) with no problems! That means you can use two 128gb cards  for a combined capacity of 256gb (approx) of storage! but wait! There's more![​IMG]... In the near future, Fiio will  release a firmware update that will enable otg capability for even more external storage capacity! *Please note that the X5 does not have any internal memory for storing music*
    On the top side of the X5 you have three 3.5mm ports, these are a headphone out(duh), a dedicated line out and a digital coax out. For my particular uses, this works out great! My current desktop setup is an older headphone amp/dac made by Headroom. The dac protion of this unit only goes up to 16/44k via usb but can do 24/96 via optical or digital coax. My old pc which is connected to this setup does not have either optical/coax out, so in this case with the Fiio X5 using the provided 3.5mm to digital coax adapter I was able to play some music files I had in Hi-Res in their native resolution through the Headroom's DAC. 
    Although I didn't get to try it out for myself, in theory, the X5 could be used as a USB to Digital Coax converter for situations like I stated above. I'm not sure if many people would use it in such a way, but good to know it's  there if you did need it.
    How's it sound?
    First of all here is the gear I used with the X5, please note that my main purpose for a DAP is to use it on the go  with iems, so most of my listening was done with the Audio-Technica CK10 and the AKG K3003i.

    As far as headphones go, I tried it briefly with my Mr. Speakers Mad Dogs 3.2 and Grado Sr325 non "i" version. 
    The Amps I used was mainly my Corda Quickstep, along with a brief audition on my Headroom Desktop Amp.
    First of all the Fiio X5 has a very nice black backgroud with my gears. Please note that my iems are not terribly sensitive such as other multi-ba customs like my recently sold jh13 for example, so keep that in mind.
    The mid bass is definitely a bit north of neutral, just enough to make it a slightly warm signature and was the very first thing that came across to me since my first listen and has remained my impression throughout my short stay with  the X5.
    I find the midrange and treble quite neutral and a little flat to be honest. I tend to prefer a slightly brighter  signature which to me sounds more lively as opposed to laid back. 
    It is important to note that even though I consider the X5 to have a slightly warm signature, there is no lack of details in the music. Even on busy passages of music, there is a spotlight highlighting every instrument. There was a  couple of times I was distracted by this which is not something I can say I enjoyed, as it wasn't natural and took the focus away from the main instrument or voice in a particular song. 

    Other thoughts...
    I love the X5 for many different reasons, here is a shortlist of pros and cons that I would like to point out:
    Having the two micro SD cards is fantastic, the line out is very good vs headphone out when using an amp, otg capability will be good to have, but not really something I see myself using. Digital Coax out to my desktop DAC,  Asynchronous USB DAC, good internal amp section, good overall UI. Manually updating the library, my 128gb sd card along with a 64gb sd card took around 2-3 minutes to scan then after that the X5 only takes about 10-12 seconds to  start playing music every time you power it up. Also worth mentioning, when it comes to updating firmware, Fiio did an excellent job at making this task super easy and it also updated very fast.

    Cons: (including some present quirks that may be fixed later through firmware) 
    Here are some of my gripes with the X5:

    When skipping songs, it is a fraction of a second too slow which can get very irritating very fast. When the unit is in my pocket (which keep in mind that this is how I use my DAPs 90% of the time) the front buttons are too sensitive and I accidentally kept bumping things(very lightly, mind you), hitting forward, pause, and the previous buttons.  While on the lockscreen (again in my pocket) when adjusting volume, if I hold down the volume rocker up or down, it also doubles as a forward and previous button, which is totally unnecessary in my opinion, so instead you must keep depressing repeatedly to achieve the desired volume. The X5 has many steps on the volume control, so when on  lockscreen in your front pocket, it is a total pain in the ***** to have to keep pressing repeatedly for desired volume. Since there are two lockscreen modes, I think Fiio should keep lockscreen 1 mode as-is, but change lockscreen  2 to not skip forward or previous track on the volume rocker.
    Another thing to note is that while I had no trouble the first time I used the X5 as a USB DAC, I wasn't able to do it again. I tried a few times, but due to lack of time, I wasn't able to fully troubleshoot and get it going again. **Please note that there have been some hardware changes in the USB interface between the tour unit and retail units and so USB functions including DAC and OTG may have improved.

    I wasn't able to do a battery test, although I found battery life acceptable, a longer battery life is always  welcomed.
    Final thoughts:
    The Fiio X5 is definitely a winner in my book and it would be very hard to beat at this price range. yes, it's a good  looking piece of gear. Yes, all the extra features are great. Yes, the UI (while not perfect) is very good, and nothing to complain about. What I really miss the most about it is it's very clean and detailed sound, and that my friends, is the most important thing of all, the sound!
    Thanks for reading!