iBasso DX90 Portable Digital Audio Player

It make more than 1 year that I listen daily to my beloved Ibasso Dx90 and I feel it's now time to make a proper review of this wonderful DAP.
 
To begin, I have in my possession this audio players in the past - ihifi 812V2, Colorfly C3, Hifiman H601 and Fiio X3- and the Ibasso is the only one I kept. It say alot I think, because the only one DAP that I regret selling is the Xuelin ihifi 812V2 and it's because of his wonderful warm Wolfson sound that is extremely different to the Ibasso Dx90 wich is more coldish-warmish and analytical sounding.
 
CONSTRUCTION :
 

 
 
The Dx90 is well built, all black brushed metal alloy with 3 big button and that's it. When my girlfriend see it she say : ''How ugly, this player look like to have been built for man only''. Well, i'm a man and find it very beautiful, it is sober, classy and dark, very dark, all black and not sensual or playfull in his look. This player look serious and sound serious. And it have it all : 3 amp gain switch, one coaxial out and one line out, volume button at the right side and on-off button at the left side, changeable battery, a micro SD slot and the most important : a touch screen.
 

 
 
FONCTIONALITY :
 
As said, physical fonctionality is quite minimalist, when the screen is close you can't use the touch screen so with the 3 big button you skip tracks or pause it easily from your pocket without having to look or pull out the player. The touch screen interface is fast and easy and firmware is quite stable but there is a LOT of them, wich can be confusing as must of firmwares have different sound signature (will talk about this later). So, you have lot of options in this little device, but this isn't an Ipod and some Ipod user did not like the ''folder'' based interface. As I listen to full album and i'm not a mix guy, this wasn't a problem for me, but I think it's better to use Flac files than Alac (mp4a) because some user have problem with tagging. Anyway, you can create playlist in your folder or inside the Dx90 easily, choose your music by directory, album, artist or genre and choose inside memory folder or micro sd card folder. Touch screen is very responsive and scrolling go well but displaying is very SMALL so it can be frustrating for people with big finger, especially taking the fact that must of time it's the thumb you use to navigate.
 
FIRMWARES :
 
10 firmwares. Plus lot of non official ones that worth the try. Firmware aren't suppose to affect the sound ''theoretically'', but even Ibasso confirm that it does make subtle change. I try them all and return to the V2.1.5 everytime (lurk version). I will say the sound signature is always similar but Low and High can change a little as well as instruments separation and ''air'' between sounds. As I feel other can sound too bright and bass shy, I sadly return to my favorite one even if it doesn't support DAC option for MAC. The 2 last versions can handle this tough, but the last firmware DAC option do not work well with my Amarra Symphony software and make clipping-static noise, I don't investigate more about this as I have other DAC and did not really care about the one of Ibasso Dx90 (I like to have different sounding source). What I care about is sound, usability and stability, and from firmware 2.1.5 to 2.4 I do not have real bugs to report with the kind of use I have. Sometime when a track change their can be a little click noise, as well as when you close the device. Something strange too is that you have to take out the battery and put it back because the player will not start for unknown reason, this can be frustrating and frightening but it happen twice in a year for me. If you do not scan you micro sd card before, sometime the album will not play fully and you will have to skip the track yourself to it to play fully again. That's about all the ''bugs'' I can find and it's perhaps due to the fact that I change firmware LOT of time and install unofficial ones too.
 
SOUND :
 
For review I use :
Headphones : Grado Sr325i, Koss Portapro, Sennheiser HD480
Earphones : Westone custom Es20, Yamaha EPH-100, Xiaomi Pistons 2, Brainwavz R3
Amplifier : Fiio E7, Sansui AU-D5
Firmware : V2.1.5L
Music Format : 16-24bit Flac 44-96Khz, Mp3 320kb, Wav
Music genre : Classical (chamber quartets), Jazz (Ecm, post-bop, fusion), IDM, Indie (female signers), Folk (Female signers), Ambient (with lot of sounds layers)
 
LOW :
As I said, I find that firmware does change the sound, not drastically, but it can push a little foward the bass with some. I said that because the Ibasso Dx90 have not a big bass impact or let's say tweaked low end, it is a neutral player that treat all frequency range equally. The extension and clearness is excellent and go deep, very deep. Decay in bass is superb, toms kick blossom in space, sub bass go well beyond hearing possible perception. The imaging of low are fabulous too and do not blur other frequencies ever, it is extremely precise and you can heard every bass line perfectly even trough big orchestra. To complement well this player, headphones with a good amount of bass impact can really make a difference. For example, I find the Yamaha EPH-100 (a bright earphones with average soundstage) to sound dry and boring with bass heavy music and that even if with some track it can exceed to render the finest details of a bass line. With the Xiaomi Pistons2 it complement superbly and make this 15$ earphones sound like a 100$ with a round, bassy and detailed sound. The Grado Sr325 complement well too, but not with electro music. Koss Portapro are a superb combination that have a very exciting sound with fast punchy bass, every Ibasso Dx90 owner should have a pair of these, the extreme clarity of Ibasso sound make an absolute duo with the somewhat dark sound of Portapro. In other words, Ibasso Dx90 have a studio like bass presentation of very detailed clarity, it is not a sensasionalist presentation, more a perfectionist one.
 
 
MIDS :
If I describe the Ibasso sound as a U shape one it isn't exactly what I heard but it's near, as a very neutral and clean player the mids do not need to be overemphasized to be enjoy. There a feeling of liquid easyness with the whole sounds layers that permit to concentrate on your favorite part of audio spectrum and pick every bit of details you want. The vocal with Ibasso are bright and superbly articulated, never the voice feel unatural or sibilant, it will be the fault of your earphones-headphones if it does. With the Yamaha EPH100 it can make sibilance and the mids are tweaked in a very bright way, with the xiaomi it help the V shaped sound to feel more articulated and hear more easily the mids without any sibilance. With the Grado Sr325i vocal are push a little foward as well and result in a harmonious and detailed whole. I find the mids even better with an amp trough the line out, especially a big one as it give a little warm to the somewhat serious sound of Dx90. What is exciting with a player that have a line out is the freedom of changing slightly the sound the way you prefer, with a line out you have a reason to make a amp collection. If I compare the Sabre ES9018 dac to the Wolfson WM8740 of the Fiio E7, I will say it's digital world versus analogue world, sacd versus vinyl, OP amp versus tube amp, purity versus musicality, hope you get what I mean. Medium frequency are more rounded and foward with Wolfson than Sabre, more easy listening type, and I admit that straight out of the DAP the Xuelin ihifi V812v2 can give more goosebumps with vocals in general, but if you use an amp with Ibasso Dx90 the story change as well as the details retrieval are way out of the Xuelin league. So, another time it's up to your personal taste, but I feel Dx90 sound is more an all arounder than Xuelin V812v2, Hifiman Hm-601 and Fiio X3.
 
 
HIGHS and TREBLE:
This is where the extreme clearness of sound display the most his strong and gracile presentation. The treble of Ibasso Dx90 is sparkly and never harsh, details retrieval is hallucinatory and can just be measure by the capacity of your earing range. Everything is there, layers and layers of easy flowing textures can build in a harmonious ensemble without effort, it flow naturally and musicaly, without ever trying to impress the highs excell and go up to top without brightness or artificial sounding. As the amount of details blossom in an airy and vast musical space, highs can feel not enough tweaked for some, the fact is you can hear more if you want, but the neutral signature of Ibasso Dx90 did not extract some specific frequency range to color or energize his sound. Even if it doesn't feel boring at all, the flatness of sound can be too polite for some, more than ever the music player ask for attention to the listener to be granted by his humble complexity. With my Grado that are already details revealing and considered too bright by some the Ibasso should sound dry and perhaps harsh but it isn't the case, and I think this is where the extremely low ''total harmonic distortion'' show the potential of the sound spectrum of extreme cleaness, even more with an amp connect to line out. With High resolution music it is even more perfect. Of all the music player I try, Ibasso Dx90 have the most beautiful and natural sounding high and for once I feel the 17hz-20khz frequency response specs can be really perceive by my hearing (and the hearing of my cats too).
 
 
SOUND SUMMARY :
 
The Ibasso Dx90 have a spacious soundstage with lot of air between instruments, it is above average but less rounded than Xuelin ihifi that use a Wolfson Dac brillantly. It can drive properly your portable headphones and all earphones are easily powered but full headphones of more than 150 Ohm or hard to drive orthodynamic isn't always used at their full potential straight off the player. You should at least use a portable amp and one with a bass boost can really be usefull too. As said, the sound feel serious, the audiophile terminology is for once appropriate to an hifi player, if you don't consider subtle enhancement in the naturalness of sound presentation as the holy grail of your audio quest I don't think this player is necessary for you. Sacd do really show what this player is capable off and you should not listen to MP3 under 320kz as you will think the player hiss while it's due to the poor quality of your music. The sound is heard as the artist in his studio wish it would, everything is discernable and can be picked up by your attention, this player give you bionical ears, seriously! It will suit most type of headphones and earphones, only over detailed or already too bright one will not complement it well.
 
 
It make more than one year that I use daily this fascinating player, I use it to plug to my system, my portable amp and to transport it everywhere I go. If you bring with you a batterypack (can use Dx90 while charging) or second battery it will have an infinite autonomy. The only flaw of this player is about the firmware but i'm not really difficult about this and never been an ipod fan, or playlist or whatever custom friendly device and of all the players I own I feel the Dx90 firmware is the most sophisticated with it's very responsive touchscreen. You should note too that the equalizer worth nothing and should ALWAYS be turn OFF. If you want more options with the firmware I advice you to install ROCKBOX to it, will try this soon but never feel the need to be lost in an abondance of options.
All in all, I adore this music player and can say my life will be less musical without it, this is sad but since I have it i'm unable to return to my Ipod touch without finding it annoying and dirty sounding. This player have the magical capacity of making souding all your headphones at their best if they are bellow 100 ohm, even cheap headphones became surprinsingly good sounding sometime with this player, it is a fascinating device that open lot of doors and I strongly advice to every new audiophile to begin with this. As said, when I compare the Ibasso Dx90 to something mass marketed like Ipod touch it is so horrifious how the Ipod is tweaked in the lows an mids that I can't even enjoy music with it anymore, the ipod bass veil everything and lack of cleaness can make distort even good headphones if they are bassy. This is one of the miracle of this player, it bring the best of all your gear.
Anyway, as perfection could not really exist in all perspective, the Dx90 still have firmware bugs that can cause frustrations and insecurity about his longevity, mine crash sometime in some mysterious way that can cause great anguish. For that, this player will not earn a perfect 5 but a still prestigious 4.5 stars.
 
 
IBASSO RULES!!!!!!
 
 
 
 
 

Inside the box:

Accessories:

 
First of all, beautiful dap! nice design, one of the most good looking daps around.

    
 
Silicon Case looks good:

 
UI is not the best part but its fair enough, and easy to use. only some touchscreen issues which has been solved after a FW update(2.3.0) 
 
Battery life is average. 6 to 8 hours max. but easily replaceable!

about SQ:
YES! SOUNDSTAGE! they were right. soundstage of this dap is amazing! separation and imaging is just unbelievable. this is the best part of this dap overall IMO.

Bass is Punchy and accurate. Powerful and detailed.

Mid is Flat and shinny.

Treble: crispy and clean! detailed.

overall sounds warm and neutral like vinyls. soundstage is just fantastic. a steal at this price tag!!.

I purchased the DX90 a week ago. I had found that I was no longer dragging out CDs to listen to music, but at the same time my MP4s on my iPhone were sounding harsh and un-listenable. As a result I was not listening to much music anymore and really missed it. I occasionally listen on headphones but mostly plug into my stereo (Acurus DIA100 and Paradigm Atom Montior v5). The sound from my iPhone was so harsh and clearly missing much of the detail of the music due to compression. My plan is to rip all my CDs to FLAC files and use the DX90 for portable listening as well as in-home listening through my sound system. I read about the DX90 and then purchased it on eBay from someone who had used it very little--he said about five hours.
 
I can't stress enough the importance of burn-in on this device. When I first heard it I thought I had made a big mistake. It sounded similar to my iPhone. I'm up to 120 hours of burn-in time right now (the manual recommends 400 hours!)--I leave it on all the time, using the provided burn-in cable. The sound has changed incredibly. It sounds very smooth, open, and detailed. My amp tends to be a bit bright, and I find that the DX90 compliments it well by being more mellow. I've read other reviews that say the DX90 is also bright or harsh, but I don't find that to be the case after proper burn-in.
 
The OS does some quirky things, like repeating a song when I press the skip forward button, but overall seems to be fine. I mostly randomize my playlist, so I just set it to random and go, so the OS is not much of an issue for me.
 
I have not taken the DX90 out of the house much, so I don't have a good sense of battery life. I plan to purchase a backup battery and always have one fully charged to grab and go as needed.
 
I have a 128GB micro SD card that I use, which holds all of my music, and I use Windows Media Player's syncing functionality so when I plug the SD into my computer it automatically syncs any new music. I'm using Exact Audio Copy to rip my CDs and find it fairly quick in processing and converting to FLAC.
 
Now that I hear the complete music again I just can't believe how long I went listening crappy lossy files! So nice to be enjoying music again.

I bought the Dx90 to replace a HifiMan HM601 player. Main reason was that I needed more storage (HM601 only takes 32gb cards). And I though this is a good opportunity to get a better player overall. Well, it is sort of what I got.

(see update in paragraph below)
Quote of my previous appreciation of sound quality:
Sound wise, I honestly struggle to ear any significant difference with the HM-601. Tried switching between both using 16bit FLAC files and both UE triple fi 10 and Sennheiser Momentum over hear and honestly the sound quality and sound signatures are very close. i.e. rich, warm and very dynamic. After some burn in (30 hours) the DX90 seems a little brighter and more open, but only very slightly. I don't have any 24 bit FLAC to test though (the HM601 only takes 16 bits). But overall, given than the HM601 uses a single old DAC (Wolfson) and costs half the DX90, I really dont see all the hype around the dual Sabre chips.

####### UPDATE!!! After writing this review I though I would carry the test again (of listening o the same track/earphones on both the HM601 and the DX90. The DX 90 has now 30 hours of listening and I went through two battery charges using the burn in cable provided. And ....

WOW .... I am absolutely blown away by how different the two player sound now! The DX90 now sounds open, airy with a huge amount of texture and details across all the frequency range ... just unbelievable. I have never been a believer of the burn in effect but I have no other choice but to admit this phenomenon is indeed real at least on this device. The HM601 sound dark, heavily veiled in comparison .... I am just amazed so much that I go back to more listening right away! ######

Build quality is clearly better that the HM601 and very good in the absolute: good size/ratios too so a very pleasing device to handle. However the switches lack crispness especially the one for the gain that often get in between positions.Other than that, not much to say on build quality.

Now it is all nice to have a touch screen (which is quite nice and responsive by the way) but what is the point of having a touch screen with such a simple minimalistic software and UI???? The HM601 had twice as many options and functions as the DX90 and I can tell you that it was not much. But the DX90 is pathetic in this respect: no file operation (I crave for a file delete), no track tagging (the HM610 had a ranking function), etc. And the font used by the default firmware is just plain ugly (thanks to Lurker for the modified firmware), and there is a lot of wasted screen space from the ugly icons at the beginning of each files.

Nice touches are the provided silicon sleeve and the screen protectors which makes sens for a portable player and already saved my screen. The battery is another average point of the DX90 because it only last about a day of on and off listening, overall not as much as the HM601. The DX90 could drive the sennheiser momentum really well although they are not particularly high impedance. So overall, a nice player and a good deal if you get a good price. However I cannot say i am blown away.

NOTE:

See update above --- After some more burn in the sound seems gets much much better more and more refined, better clarity, better texture better soundstage, better everything.
I dearly miss the analogic volume control of the HM601. Digital volume controls just suck in general

Hi guys, this is my first post and my first review.
 

I own a useless Fiio X3, its battery died and I have removed it because it was inflated for unknown reasons (I used to charge it with a Samsumg 5.0V 2.0A original charger). Although I was not impressed with the sound, I liked the solid construction and the features it has.
 
Then, I got the Fiio X5, again the solid construction, features etc. had impressed me but in this case the sound impressed me too, at least I felt that I was using a real Hi-fi DAP, I was happy with the X5 (but I decided to sell it).
 

 
Finally I got the DX90 too, I was interested in the iBasso DX90 because I had been reading a lot of good things about iBasso and its products. I have heard about its nice detail and impressive separation and in second place I was looking for a DAP that tempered a little bit the forward sound of my headphones (RS1e).
 
The things I like about the DX90 over the Fiio X5 (Firmware 2.20) are; its touchscreen, size, weight, replaceable battery (compatible with the Samsung Galaxy III), far better SDXC compatibility, and its OS based on Android (right now I have the Lurker0´s 2.2.0 L0 Firmaware, but also exist the Rockbox option).
The UI although not perfect so far is very good, intuitive and usable and I love the physical buttons in the front too. Like with the X5 I never had problems with the file scan or external DAC (Windows 8.1 64 bits).
 

 
The DX90 is very detailed, smooth, very exiting sound and great instrument separation, right now is my favorite DAP and I highly recommend this product.
 
Note: the new 2.2.0 FW has introduced a great SQ improvement and features, Ibasso as always is working on it, great post-release support!
 


(Updated with some pics)
 
Saludos!

i've had my dx90 for some time, having bought it when the price was still about $420.  i thought it was a great value then. it's an even greater value now.
 
i'm using the 2.0.5 firmware because i'm happy with the sound and am not willing to roll the dice on any changes.   i find the interface exceedingly easy to navigate, but must note that i use a folder structure instead of tags, and so can't comment on tags and playlists.  similarly, i should note that i am listening mostly to classical and a bit to jazz and, rarely, to pop.
 
i've got a 128gb microsd full of classical music in flac format riding in the player most of the time.  i also carry separately a 64gb card with jazz and pop.  switching from one to the other is a matter of seconds.
 
i listen on either akg k812's or etymotic er4pt's, depending on my need for sound isolation, and those pairings work well.  the sound is wonderful: rich, detailed and immersive, with good separation and tight, clear control across the whole frequency spectrum.  whether listening to a bach violin partita or a brahms symphony, the imaging and reproduction are great.  the dx90 set on high gain was also quite capable of driving the hd700's i no longer have, but produced a smaller soundstage on those 'phones than when they were driven by a more powerful amp.
 
the size and weight are very handy - those specs are widely available and it's easy to compare them with, e.g., the fiio x5, and see how the dx90 is smaller and lighter, easier to tote around. i can't compare sound signatures as i haven't heard the x5.  the dx90's ability to switch batteries means that you never need to run out of power.  it uses widely available galaxy s3 compatible batteries. battery life might be about 5 hours playing from flac level 5, but i've got several spares i carry fully charged, and the whole package is still quite manageable.  [i ranked the battery life high,  because although the play time of a single charged battery is quite limited, the ability to switch in a new battery means no practical limit.]  alternately, some owners use larger batteries, foregoing the metal back-plate and just relying on the supplied silicon case to hold the battery in place.
 
the touch screen is quite sensitive, even with a screen protector, and it took a while for me to develop a light enough touch to move around easily.  this is not a big deal, but was irritating at first.
 
on the whole, i don't hesitate to recommend this player.

This is my first DAP. I bought it in August with  pre-installed 2.1 firmware and I have to say I am positively surprised how great this player sounds.
I honestly can not compare it with other DAPs like Fiio X5 or HM -801,  because I haven´t simply had a chance to listen other DAPs.
Nevertheless, I can wholeheartedly recommend this DAP to anyone who seeks neutral, spacious sounding DAP, with excellent tonal balance and dynamics.
From my point of view, it makes perfect sense to buy a player which does not colour sound and is as much neutral as possible,  because it gives you an extra flexibility to choose headphones with sound signature according to your preferences. For instance, I decided to buy Yamaha EPH-100 and this combo sounds superb. Warmer sound of EPH-100 provides extra musicality to amazing transparency and clarity and thus creates for me pleasantly coloured tonal harmony. I have to say my other phones, Beyerdynamic DT 990, also sound very good with iBasso DX90, especially  when running on high gain. Balance and versatility are  strong points of iBasso DX90. In other words, frequencies do not "compete" with each other, they "cooperate" with each other. Overall tonality is therefore quite neutral without being boring ! Sabre ES 9018K2M  DAC with amp section is simply doing excellent job. My Beyers DT 990 Pro are 250 Ohm version and are generally not so easy to drive with unamped portable devices such as iphones, laptops or tablets. iBasso DX90 is handling DT 990 very well on high gain. Its still fine on medium gain, but on high gain its just better. Everything is improved - bass quality, dynamics, soundstage etc. On high gain I can get comfortable listening at around 210-220 volume level.
Bass on high gain with DT 990 has very good impact and control, midrange (which can sometimes sound recessed on DT 990 when  the headphone is underpowered) is smooth and solidly presented,   treble is very well extended and still, typically Beyer-like, elevated without being harsh.
iBasso DX90 + DT 990 or EPH 100 sounds fantastic with high quality lossless files. Another good news is that the sound keeps on improving with time.  I am not a great judge on so called "burn in", but I feel the sound is getting slightly better and better. (It is not a night and day difference but I think its a bit smoother than in the beginning).
Other things worth to mention is the device has a really good build quality and an user friendly interface.
 
Bottom line: I think iBasso DX 90 represents tremendous value for the price. The only drawback I can see is the battery life, which is only average (at best). However, for me it is not a serious problem, because I rarely listen for more than 3 hours per day. Highly recommended !

I just received this device, along with a FiIO X5 to replace my now discontinued iPod classic.
 
At first I liked this device - smaller, lighter than the FiIO, although only 1 slot.
 
Shipped without any user guide, however.
 
I formatted my 128 G SD card and inserted it, connected it to my mac.
 
I used doubleTwist software (which I had successfully used with the FiIO, and let it sync overnight.
 
I came back and and the device seems to think I had no music. I plugged the USB cable back in, and the files where definitely on the card.
 
Tried factory reset, tried formatting as exFAT.
 
I went to their website - www. ibasso.com - and it is a mess. Every link leads you to their download area. 
 
I have the latest firmware v2.1
 
I emailed their support but haven't heard back.
 
So, the device can only find files on the built in storage.
 
So, as a "high end" player, this device is useless.
 
Until the hardware companies start making software at least a little better, acceptance of these products will be low.
 
The FiIO X5 was difficult enough to set up - took a while to locate the doubleTwist software. Copying files from the Mac to the DOS formats using the Finder
creates little .trackname files so that every album looks like it has two copies of each song.
 
I will try to assemble the packaging for a return.
 
Rick

This is the best DAP I have owned so far...I am loving it =)   Very good DAC chip and decent built-in amplifier, this is a steal at this price tag

I've been listening to my iBasso DX90 for several weeks and I'm extremely impressed by its sound, its ease of use and its firmware updates that are more than just cosmetic improvements. While I was deciding whether or not to purchase the iBasso DX90, I spent quite some time comparing it to the FiiO X5 and the wallet-busting Astrell & Kern AK240. In another life, when I return as a billionaire playboy, I will purchase the AK240 or its upgrade so the choice was effectively between the DX90 and the X5. My comparison eventually centered on the iBasso DX90's use of dual Sabre ES9018K2M DACs. I was also swayed by the DX90's apparently superior handling of micro SD cards in comparison to the FiiO DAP, which some reviews of the X5 have criticized as being problematic when using cards larger than 32GB.

The DX90's sound can only be described as luscious and rich. The dual Sabre DACs produce a fullness and an elegance to music that makes lengthy listening sessions a pleasure if not an addiction. Owners of Sennheiser's audiophile grade HD650 headphones will recognize this comparison: the sound of the DX90 is the DAP equivalent of listening to music through a pair of 650s. There is a similar rich sound quality.

Using the UI is simple and intuitive with just enough menu choices to make finding music easy and fast, though the display graphics are antiquated and primitive. One UI attribute I've found particularly helpful is the "directory" menu selection. which calls up all of the nested music choices in an easy to manipulate manner, breaking them down logically rather than in the hodge-podge mess you usually get. If you transfer a lot of music files from a box set, you will appreciate this feature's logical and intelligent presentation. The latest firmware update added several menu choices, The addition of a charge-only USB selection, added to the previous Storage and DAC choices, keeps all of the DX90's operations nicely compartmentalized. Gapless playback really is gapless, Play Modes are simple to manipulate. Music information is easy to call-up and fairly exhaustive.

High resolution playback of up to 24/192 has been error-free except for one album which proved troublesome, causing the DAP to hang after a selection was played. I have reason to believe that the error lays in the album's hi-res encoding and not the player. I haven't been able to reproduce the problem with any other hi-res files. The DX90 plays FLAC, APE, MP3 and WAV files with equal facility. I've found no difference in performance. I haven't tried DSD or DSF files yet, though the twin Sabre DACs appear capable of playing them. However, DSD files are not listed as playable so failure won't be unexpected.

One slightly annoying hardware problem that's cropped up is the headphone jack's selectivity when choosing which 3.5mm audio plug to accept and which to reject as being ever-so-slightly too wide. It becomes necessary to force the plug into the jack when this happens, something that makes me very uncomfortable. A couple of my portable headphones produce only a watered-down mono sound as a result of their rejection by the DX90. Since I own several pairs of portable headphones this is not a serious problem at the moment.

Charging the DX90 takes about three hours when using an AC converter, six hours in a powered USB slot. The DX90 is a bit of a battery hog, with around 7-8 hours of usage at standard resolution and volume, 6-7 hours while playing high-resolution files at higher volume. There is a rudimentary EQ included which lowers the volume when in use so compensation will be required. I tend to avoid using EQ unless absolutely necessary. There are several other features, all of which I found simple and intuitive to use. I've been using 128GB microSD cards, which are necessary since the DX90 only has about 5GB of internal storage. This was an obvious trade-off to keep the price down.

The DX90 is a superb sounding DAC, a great value at its sensible price point and quite easy to use. If you're searching for a reasonably priced DAP capable of playing high resolution music I think the DX90 is an excellent choice.

I'm going to skip parts about build quality and UI of DX90, as lots of words have already been written about those aspects of that DAP. After switching form HM-901 it seems more than OK for me. And even though DX90 isn't perfect usability wise, I've found it quite enjoyable to use when I'm on the go. What I can do is to tell you guys how my adventure with that device looked like.
 
At first, DX90 came into my hands and at that time I had "only" HM-901 nearby. But when my boss ordered me to write review of ten audiophile DAP-s, I had opportunity to compare them all with DX90. In that publication there were MA9, X3, X5, DX50, DX90 obviously, HM-901, HM-802, HM-700, AK120 and AK240. To make it short, iBasso has nothing to be ashamed in comparison to nearly all of those devices. Yes, AK240 is above everything these days in many aspects IMO, but AK120 - not really, I've foud that this DAP is very comparable to DX90 sound and UI wise. And price difference between them? Well, staggering. That's all I can say.
 
In my opinion, the best price-performance factor of all those players belongs to DX90, and HM-700. In terms of pure SQ I'd put DX90 below AK240 and HM-901, on par with AK120, and above all other DAP-s. You can agree with that or say, that I'm over my head. But the fact is that I've listened every hi-end DAP out there on the market, except DX100, I own many of them. And I just am very impressed about what iBasso guys did for mere 400$. That's amazing.
 
Two, scratch that, three disclaimers before we go:
 
1. I've payed for DX90 full amount, no free samples this time for me, no journalistic surprises or secrets here.
 
2. I'm not affiliated with companies mentioned in this article in neither financial, nor personal way. Though, obviously, I know PR people working there, but we get along only on professional level and that's it.
 
3. Sorry about my language skills, I'm aware that they could use some improvement. But I honestly believe that by writing stuff such as this review I'll get better. If you consider yourself as a language purist and are afraid your eyes might fall off, please stop reading here. 
 
List of music I used is quite vast: Nine Inch Nails, Bat For Lashes, Rebecca Pidgeon, Einsturzende Neubauten, Corvus Corax, The Knife, Fever Ray, early albums of Mike Oldfield, Filter, Wardruna, Pig, Ministry, Michael Goddard/Monteverdi, Dead Can Dance, KMFDM, Jarboe, Muse, David Lynch, Therion and some Chesky's stuff to name a few. No additional details are needed here, but if someone asks about specific tracks, I'll gladly answer.
 
DX90 (FW 2.0.0) vs HM-901
 
OK, it's time for the good stuff. I'm not going to write DX90 comparison to all big models out there, I'll just focus on differences with HM-901 on the other hand. It's couple times more expensive, so it'll do just fine. In my test I've used RE-600 and Heir Audio 8.A. In the very beginning it's fair to say that DX90 and HM-901 have almost nothing in common, even though their DAC-s are somewhat similar. But the fact is, that if DX90 turns out to be somewhat comparable to HiFiMAN-s flagship, then value of this DAP will be obvious.
 
Another thing worth mentioning is that compared DAP-s have different sound signatures, so it's another obvious thing to write that if some headphones, IEM-s or CIEM-s will go nicely with DX90, they don't have to with HM-901 and vice versa. To be honest, my 8.A go better with HM-901. They are thick sounding, with lots of bass, and HiFiMAN-s flagship keeps them tight sounding, precise, punchy as hell, detailed and very organic. In comparison to DX90, HM-901 has more punchy lows all the way, from sub levels to kick bass. To be honest I don't think that I'll hear more power in that FR in any other DAP, I just can't imagine that. HM-901 has midbass hump, and I believe that this makes lows so powerful overall. So logical thing is that DX90 has that parts of FR more polite and without any midbass emphasis, which is normaly a good thing in my book. But bear in mind that DX90 sounds very, very punchy as well, it has excellent dynamics, to my ears better than AK120. To be honest, HM-901 is a king on that particular field, and to fall a bit short in a fight with a king is not a shame. Not to me. DX90 is second best I've heard thus far in that regard. And I've heard a lot. Dynamics and punchness are the very first things listener notices with this DAP. Both compared devices have excellent low end overall, very well controlled from A to Z, tight and enjoyable all the way, but different.
 
Midrange is also presented differently by both DAP-s. But in that regard they do sound as a reference to me. Presentation is clear, natural, smooth and effortless, everything is top notch there. For me that smoothness divides "OK" DAP-s from the ones that are excellent. Guitar parts played by HM-901 have a bit fuller body, and they do sound a bit more clear. DX90 is not too far off, the same instruments sound more relaxed, calm. HM-901 has also more highs, but both devices have them smooth and clean, no sharpness at all. At lest not with music I usually listen to. Though one thing deserves mentioning: DX90 is more forgivable for badly recorded tracks.
 
DX90 is bigger in terms of soundstage on both levels: width and depth, though main differences are heard in the center of the show. In some recordings DX90 withdraws vocals a bit too much for my taste, HM-901 has them ocasionally too close, so they're even And don't get me wrong, I don't think bigger soundstage is better one. HM-901 is more aggressive and direct DAP overall and it has more body here and there. So his close presentation to the listener is something logical for me. But it's also more airy and DX90 has not only bigger, but also thicker soundstage. Therefore apples and oranges, lads. Both devices have that aspect very natural, organic and coherent. Even though DX90 is darker sounding DAP, it's equally detailed.
 
Final words 
 
To make it short, iBasso delivered us a monster. DX90 is hands down the best price-performance DAP for me now, and one of the best DAP-s SQ wise overall. This brick has huge potential, and I'm sure even iBasso guys are surprised by how well it sounds. For 400$ it's a steal. If you're into that sound signature, grab one DX90 for yourself, you won't regret it.
 
_________________________________________________________________________________
Cheers,
00L
 

Lets talk a little on my background. This is my first review, any comment would help me to improve.
I joined orchestra and school band in my high school age, playing brass instrument (B flat trumpet), play piano to Grade 5, not to say a pro player but I then learn to appreciate music, all kind of music.
More of a mobile user, so I won't be reviewing the amp section as I use IEM on my daily basis. The only headphone I had was Denon AHD2000 and Audio Technicha AD700 which is pretty easy to push, any player should have them played without issue.
 
I had currently three IEM left in inventory but only paired Westone 4 and Xiaomi Piston with DX90. Ficher Audio DBA2 MK1 is with my brother so I have no chance to test with it yet.
Personally I don't believe in burn-in hype so I did not leave my player playing songs overnight. Current up-time is around 24 hours on and off.
 
Owned DX100 before for almost 2 years but I sold it for Dx90 for its portability. Didn't do it on purpose, initial plan was to get iRiver AK120. Sold a few weeks before I learn about DX90.
 
Design
Since Dx90 should fall under a portable device category, it is fair to say that Dx90 is quite portable.
 
Dx90 rated : 
Case dimension: 2.52W x 3.98L x 0.67H (inch)
64W x 100L x 17H (mm)
Weight: 140g or 4.94oz
 
While Dx100 is obviously bigger than Dx90, HM602 rated :
Size: 62mm*103mm*26.5mm or 2.4 * 4.05 * 1.04 Inch
Weight: About 200g / 7Oz
which is just a little bit lighter than HM602, and a little bit thinner. AK100/AK120 would be the most portable player I have learn so far.
 
Physical buttons of Dx90 is not bad by far, three buttons on front panel (Back, Play/Pause, Forward), power button and physical button lock on the left, volume up-down on the right, gains toggle on the bottom. The output jack and input jack seems to be better quality than dx100 and hm602. iRiver AK lines is still winner on the design, but dx90 is not left by far.
 
Battery Life
iBasso rated Dx90 could operate 8.5 hours, Dx100 7 hours, HM602 9 hours, AK100 16 hours and AK120 14 hours, but the user replaceable battery still makes Dx90 a potential winner as we can prepare as much battery as we need while in travel. 
 
User Interface
User Interface of Dx90 is a love-hate situation for me. It is simple but that lacks of easy retrieval way of information, that includes making navigation a hassle sometimes. This could be workaround by using shuffle mode and a playlist but I have no problem with AK lines' UI. Button is too small, so as the screen. Coming from Dx100 and iphone 5s makes me feel that the screen is too small for touch screen navigation. Although the UI response time is better than Dx50 but I think it could be better. Scrolling the folders lead to accidental "click". They need to improve the UI in future firmware or else someday people might exhaust on trying to navigate a song.
 
Firmware
Another big problem is with the firmware. I have no problem with the scan time, it is improved due to a different hardware implementation (eg dual core cpu), I have no problem either with how it can only charge and listen with a charge only usb cable. Listening is not allowed when your pc is accessing your dx90 storage. but I have a big problem while they released the USB DAC feature without 64-bit and Mac drivers. (yet. customer service replied that 32-bit driver is added but never mention anything additional to 64bit driver and Mac driver). Sometimes song will be cut off after 1-2 seconds of play, back and forward button will sometimes delay 1 second+ as well, but that shouldn't be a big problem as that doesn't affect its core - Sound Quality.
 
Sound Quality
The best part of Dx90 is the sound quality. Despite of those Firmware and UI bug, it is indeed a very good sounding dap, for its implementation Dual ES9018K2M, each for left and right. Despite of the technical specifications 8 core vs 4 core (ES9018 vs ES9018K2M), I think the Dx90 sound quality is not far behind Dx100. Some song sounds better than Dx100 indeed, to my favour. Not far behind from AK120, but the most important thing to remember, they all sound different. This dx90 is definitely sound better than HM602 to my liking, the dx90 is spacious, I cannot say it is lack of soundstage, they are big indeed but you're like sitting very close to the performer. The "live" performance is happening quite near to you. The instrument separation is good, you can easily differentiate what instrument is included in the recording.
 
One thing special about Dx90 is you can imagine (or listen to) quite a lot of the ambience. You can listen to the piano sustain pedal, clarinets and oboes tick-tocking pad hole, you can listen to the air hissing in the background, don't be surprise if you did not listen this on other dap, it might not be your faulty dx90, but it is just resolving some adds.
 
Sound stage, using Family - DreamGirls soundtrack (16bit/44.1khz), Mahler Symphony No.5 (24bit/192khz), Hotel California - The Eagles (24bit/44khz), Skyfall - Adele (16bit/44.1khz).
in the track Family, all singers are singing in the same position, or slightly close to each other, this is defer from what I've listen from Dx100. Dx100 sounds as like singers are standing far apart, which is different from the movie. They should position quite close to each other as like in the original movie. For Mahler Symphony No.5, instruments like trumpet shines, bright and outstanding; Cellos and double bass goes extended deeper, it sounds quite similar to the Dx100 in this aspect, just that Dx100 has a better dynamic.
 
Things were comparable on AK120. I can't really differentiate their difference on sound stage and dynamics, but different sound signature, yes. On Hotel California, the guitar in the beginning were almost as sweet but the bass afterwards coming in sounds different. AK120 does not decay fast, makes a good echo of the floor tom (I believe it is floor tom), Dx90 and Dx100, that tom sounds tight. Less there are. Overall sound signature for AK is warm, and thick. Dx90 sound neutral but not flat. That quickly judge when The Eagles start to sing, focus immediately goes to the singer without a blur line there. The Eagles sounds equally nice on AK120, DX100 and DX90, but the backing singer were more precise on harmony on DX100 imho. Followed by Dx90, they make a very good harmony by not outstand each other. On AK120 the backing singer is really sound backed, they positioned a little bit behind on the stage.
 
The volume of AK120 easily become shouty at above 55. I'm okay with Dx90 at around 205-210, it is become too loud when Dx100 reach 205. The 255 step volume controller is for me more precise and nicer to use. instead small changes on volume for AK120 makes big difference of volume in my opinion. Adeles' Skyfall needs a bigger soundstage, as for me DX100 is superior than both AK120 and Dx90. I cannot really tell the difference on this track other than different sound signature and texture, especially when Adele sounds equally perfect in all dap. Only thing I wish to listen more strings instrument in Dx90 than those brass and percussions. String instruments are important don't you agree? In AK120 and Dx90 i felt that the strings is overwhelmed by brass and percussions, which in Dx100 it is quite perfect for my liking.
 
Other quick listening session on A Great Big World - Say Something, John Legend - All of Me, some old Japanese song like Nada So So, XJapan - Kurenai/Crucify your love/Art of Life, some nasty mandarin songs that have simple chords, piano master like Yiruma - River Flows in You, Kiss the Rain, The Letter, sexyphone Kenny G, and much more, DX90 is a good companion for many genre. It justify the price of $419, and for its portability, it can be used everyday. Waiting bus/train, in a library, dinner alone, shares music with your loves one, it justify most of the situation where a dap is needed.
 
Value/Conclusion
I only owned one player which is HifiMan 602 where the price range is suitable for comparison. Dx100 is good but for that size and weight it should be a desktop rig rather than a portable rig, and is price at $829. AK120 is almost 3 times more expensive than Dx90, but provide better UI and Firmware, slightly warm sound signature, and equally portable compare to Dx90. If you have budget and crave for sound quality you should really go to AK120. 
 
My personal favour (only SQ is considered)
DX100 > DX90 > AK120
 
My personal favour (all elements are included, exclude price )
AK120 > DX90 > DX100

I’m sure that if you are on Head-Fi once in a while and you are interested in portable audio, you will at least have heard of iBasso. The DX90 is iBasso’s third DAP, the first two being the DX100 and the DX50. The DX50 turned out to be a huge success right off the bat and the first few batches were sold out very quickly. I wrote a review for it a while ago and I thought that despite the shaky UI at the start, the DX50 was an exceptional product after iBasso came out with some firmware updates. Another interesting feature that the DX50 had was firmware rolling. Each firmware seems to sound different and users can pick the firmware they like best.
 

BucketInABucket's picture of the DX90. 
 
Sorensiim created a thread asking for a DAP inbetween the DX50 and the DX100, the iBasso’s flagship DAP. The DX90 is iBasso’s answer to that. When the specs were first released, it was noted that the size would be exactly the same as the DX50 but it would have dual Sabre ES9018K2M chips in the place of the single WM8740 the DX50 had. However, the battery life was going to be somewhere around 8.5 hours. I was quite amazed to see that they had crammed all that into the DX50’s casing without sacrificing too much battery life.
 
I certainly had very high hopes for the DX90 because I had a very pleasant experience with the Japanese DX100 in terms of sound quality and they both use the ES9018, but the DX90 uses 2 mobile version one instead of the more power consuming desktop one that is in the DX100. Anyway, let’s move on to see how that DX90 actually did.
 
Disclaimer: **I am in no way affiliated with iBasso and I will do my best to write an unbiased review. **
 

BucketInABucket's picture of the DX90's back. 
 
Specifications
Here are the specs for the DX90 and if you compare the headphone output power to the DX50’s it’s not too different, but the sound is very much different. The output impedance is as low as one could hope for, it should not have any bass problems with even the lowest impedance IEMs.
 
Line out:
Frequency Response: 17Hz~20KHz +/-0.1dB
S/N: -119dB +/-1dB
THD+N: 0.0015%
Crosstalk: 115dB (1KHz)
Output Level: 1.7Vrms (1kHz 0dB)
 
Headphone out:
Frequency Response: 17Hz~20KHz +/-0.1dB
THD+N: 0.0015% (32ohm load)
Output Level: 1.3Vrms(Low gain), 2.0Vrms(Mid gain), 2.8Vrms(High Gain)
S/N: -118dB +/-1dB(Low gain), -116dB +/-1dB(Mid gain), -115dB +/-1dB(High Gain) (32ohm Load)
Crosstalk: 75dB (1KHz,32ohm Load)
Output Impedance: <0.1ohm
 
Battery Life: 8.5hours
 
Audio Formats Supported: APE, FLAC, WAV, WMA, AAC, ALAC, AIFF, OGG, MP3
 
 
Unboxing & Accessories
The DX90 box is basically identical to the DX50’s box except for the DX90 instead of the DX50 (obviously). It’s very simple and not the best for the price, but it gets the work done and possibly keeps the price down. Upon opening the box, you will see the DX90 and under it is a compartment with all the accessories. It isn’t bad by any means, but it isn’t great either.
 

musicheaven's picture of the DX90 and its box. 
 
There are quite a few accessories that come with the DX90. There are 2 screen protectors just under the DX90 and it comes with a coaxial cable, a burn in cable, a micro USB cable and a silicone case. For me, this is completely fine. The USB cable is pretty nice and works. I can’t test the coaxial cable unfortunately, but I’m sure it’s fine. The burn in cable is pretty cool and a nice touch considering iBasso recommends 400 hours of burn in. The case is a nice addition, but it is a little thinner than the Mini Audio case I got in Hong Kong, but it works well.
 
 
Design & UI
Personally, I think the DX90 and DX50 are one of the best looking DAPs, just behind the AK100 and AK120. I love the brushed metal finish, but I’m assuming most people use the case, so you can’t see it unfortunately. The DX90 has custom jacks that are supposed to be very durable and able to be plugged in and out approximately 10000 times. Honestly, you can hardly tell them apart from the DX500 without a closer look. The jack area has more silver and the back says DX90; other than that there are really no differences.
 
I don’t really want to judge the UI right now, it’s still got some flaws the DX50 had. I will update this later when some new firmwares are out. Right now there are some problems with scrolling and the last couple of second of each song being skipped.
EDIT: The scrolling and skipping issues have now been solved and it works very well and is much easier to navigate now. The UI is very smooth and quickly and very rarely stutters. No problems whatsoever. It is one of the best laid out UIs I have used on a DAP - it's no Poweramp, but very nice for a DAP. 
 

brugis' picture of the DX90 next to the DX50. 
 
Testing Gear
I like to list the gear that I tested on the DX90 and a short not on how they paired. The main IEMs used were the DN-2000, DN-1000, AX35 and I listen to the H300 for quite a few hours as well. The Dunu IEMs paired extremely well with the DX90, I think the DN-2000 paired a bit better though. The AX35 was fine as well, but they a league behind the Dunus. The H300 was an average match – it wasn’t great, but it wasn’t too bad either. The H300 is one of the peakiest IEMs I have heard and on the DX90, the upper mids were too accentuated and the treble was also too sibilant for me. However, when I added an O2, the H300 seemed to sound a lot better, the upper midrange was still there, but it was less of an issue and the treble was tamed a little as well. I also used the MS1 Alumod as the main headphone and the DX90 did extremely well, there was not much difference between running them from the DX90 and a V200. Another headphone I tried with it was the Fischer FA-003, which went together extremely well. The bass was very accurate and the entire sound was very detailed. On to amps, the O2 didn’t really have much of an improvement for any of the IEMs and headphones except for the H300. The UHA760 was similar too. I wouldn’t bother amping the DX90 if you are just going to use IEMs and easy to drive IEMs.
 

My DX90 with the Alumod Alessandro MS1. 
 
Sound Quality
I had huge expectation on the DX90, as I’m sure many other people did as well. With its dual ES9018K2M DAC chips, I really expected the DAC to be something special. The specs of the DX90 and the early reports seemed to contradict each other a little bit. The DX90 has a little bit more power in low and mid gain, but less power on high gain compared to the DX50, but people were commenting on how well the DX90 drove their headphones, even the HE560! This certainly got me intrigued and when I first got the DX90, I tried it with my HE-500…
 
 
DAC Section
As I mentioned above, the DAC section is made up of 2 ES9018K2M Sabre chips. I used to own a Japanese DX100 that used an ES9018 (desktop version) and I absolutely loved the detail and clarity that came from the line out. I’ve been a huge supporter of Sabre chips since then, but obviously how a DAC sounds also depends on how the chips are implemented. I must say, iBasso pass with flying colours here. The line out sounds extremely detailed, and is incredibly clean. This is IMO, a huge upgrade over the DX50’s already nice line out. While the DX50’s WM8740 was a little on the warm side, the DX90’s line out is more on the cold side, which happens to be my preference.
 
 
Amp Section
As I mentioned above, the early adopters said that the amp of the DX90 was quite an improvement over the DX50’s amp when used to drive full sized headphones like the HD600 (which is quite hard to drive well). I found that the amp section of the DX90 had more control and dynamics when compared to the DX50’s amp. Some people have mentioned that the DX50 has a weak amp and while I do not agree with that, I do see why people think that. Although from the specs, the DX90 is not much of an improvement, sonically it is much better. I find adding an O2 (my reference amp) to not have much of a difference and sometimes it actually sounded worse (the O2 is a little recessed in the higher midrange IMO).
 

tin427's picture of the DX90 and his CIEMs. 
 
Bass
When I first heard the DX90, the first thing that hit me and really stood out was the bass. While I wouldn’t really call the DX50 bass light, I found it lacking just a little bit in the lower sub-bass area a bit. The DX90 completely solves this issue and the sub-bass is more prominent, but stays true to the recording. At no times did I feel like the sub-bass would have too much rumble, it is very controlled and accurate. In terms of mid bass quantity, the DX90 is very similar to the DX50, it might have just a touch more mid bass. The detail of the bass is simply stunning, I have never heard strings from a bass guitar tremble or the tiniest detail from each drum beat from my DN-1000 before. The last time I was amazed like this was when I first heard my HDP-R10. What is a little worrying is that iBasso tends to change the sound very slightly with each firmware and right now, I find the bass to be absolutely perfect; I certainly hope that they keep the bass the way it is.
 
 
Midrange
Something I found interesting about the DX50’s last firmware update was that it seemed to somewhat accentuate the higher mids. I quite liked this on the DN-1000, but I recently tried it on the H300 and it was not a great pairing. I was hoping that iBasso would stick to a more neutral sounding midrange with the DX90 to be safer and I’m relieved to say that they did. Actually, I find the DX90’s midrange to be just about colourless, it is IMO, dead neutral. This really allows the headphones to sound like they are “supposed” to in the midrange, for better or worse. For example, I loved them with the DN-2000, the clarity and detail was just amazing, but the H300’s midrange was too sibilant and sounded a little off. I did use the DX90 with the UHA760 and I really preferred the DX90’s midrange by itself more than amping it. On a whole, the midrange is very detailed with the instruments and I especially enjoyed vocals on them, they just sound so realistic!
 
 
Treble
If I recall correctly, when I first received the DX90, I felt like it was a little dark in the treble, which I found odd. For those who don’t know, iBasso’s house sound leans slightly to the bright side, and coincidentally, so does my preference, which is partly the reason why I loved the DX50 and DX100 so much. The treble almost sounded like a Fiio (generally quite warm) at the beginning. After contacting iBasso, I was told that I should burn it in for 400 hours before judging it, and that’s what I’ve done and boy, has the treble changed! The slightly rolled off treble has now turned into something completely different – the very slightly bright sound that we all know similar to the DX50. The treble is wonderfully details and very well extended. It does not in the slightest sound warm or dark at the start. Cymbals are very clean and detailed, but never harsh with the DN-1000 and 2000. For me, this is the place where the DX90 beats the X5 (from memory); the cymbals just sound better reproduced and sound more natural.
 

kkcc's picture of the DX90 and the Dignis leather case. 
 
Separation, Detail & Clarity
The separation and detail really hit me when I first heard the DX90. It was just superb. Let’s start with the separation. This is the area that I feel is the largest upgrade over the DX50. I loved the DX50/O2 and DN-1000 combo because the separation was improved quite a lot when amping the DX50. The DX90 sounds better than the DX50 and O2, which is quite a feat indeed. The instrument separation especially is amazing, it never gets congested with the DN-2000 and instruments that hide in the background with the DX50 + amp can be heard on the DX90. As some may know, my test track for vocal separation is Fun.’s “Some Nights” and the DX90 was quite simply amazing. I have never heard such good vocal separation from a DAP, from memory not even my HDP-R10 matches this. For both instrument and vocal separation, the DX90 scores full marks.
 
The detail and clarity in the DX90 is also very impressive. I honestly did not expect it excel in this area. Because of the separation, little details manage to make its way through the music. At times, I heard things that I have never heard before on any IEM, even my Miracles (I sold them a while ago though, so don’t hold me on that). The dual Sabre DAC in the DX90 is extremely detailed and with the much improved amp section, the DX90 really is quite a detail monster. Clarity is top notch as well, instruments are not too sharp, but just right and sounds very natural. Vocals are extremely clear with the smallest detail being heard. You can even heard the singer breathe on some songs. These few areas are perhaps the DX90’s strongest parts, it truly blows away the DX50.
 

destrozer's picture of the DX90's box. 
 
Soundstage & Imaging
Ah, how I miss the DX100’s huge, expansive soundstage… When I first heard the DX50, the soundstage was quite small and in your face, but later on, with firmware updates, the soundstage opened up. However, if there is one complaint I have to make against the DX50, it would have to be its soundstage. I really longed for the DX90 to have the huge soundstage like the DX100 and boy, have they delivered. The soundstage is perhaps not as large as the DX100, but it is certainly extremely close. On some well recorded tracks, the soundstage is very much concert hall like and the most impressive aspect of it is the width. It seems to have music coming from the very edges of the stage (if that even makes sense?) and the DN-2000, which already has a very impressive soundstage just sounds epic on the DX90. The height is better, but not by too much, not that recordings have a lot of “height” anyway. Depth is also something that has been improved a lot, it seems to just have more space in the way it presents music compared to the DX50.
 
Personally, I think that imaging is somewhat linked to soundstage; if the soundstage is small and cramped, the imaging can’t be too good either. With the large soundstage of the DX90, it seems much easier to position where each instrument or singer is. While the DX50’s imaging is awesome for something that costs $240, the DX90 is, quite simply, in another league. The DX90 absolutely kicks the DX50’s ass (as it should considering it costs almost double). On the few tracks that the DX50 struggled on imaging, the DX90 flows extremely smoothly and has no problems. Everything seems much clearer and you are almost there at the performance, looking at where each thing is on the stage. It’s kind of like a HE-500 and HD800 in regards to imaging and soundstage. The HE-500 is very impressive with both, but the HD800 is just better.
 

some4ew's picture of his DX90 with the ATH-L3000.
 
Presentation
Different pieces of gear present music in different ways. For example, Grados are aggressive and in your face, while the HD800 is more like you are viewing a performance up on a stage. The DX90 are definitely at the HD800 end. It has a very spacious presentation which seems effortless. Some people say that the DX90 sounds “digital” next to the AK240. I’m not sure what this means exactly, or maybe I will understand after I listen to the AK240, but the DX90 does not, even in the slightest, sound digital to me (whatever this means). Another impressive trait of the DX90 is its layering of music. I’m not really quite sure how to describe this, but I am hearing layers of music behind each other. This is something that was definitely not there on the DX50. I really love the way that the DX90 presents the music, it just seems so natural and lifelike.
 
 
Accuracy
So just how neutral is the DX90? First of all, sound is very subjective and of course, everybody’s understanding of neutrality will probably be different. For me, the DX90’s bass is almost flat, but may have just a tiny sub-bass boost. The mids, for me, are perfectly flat and I honestly could not ask for anything more neutral here. The treble has a nice little sparkle to it, which makes the sound just a bit more exciting. If I had to describe the DX90’s sound signature, it would be very (I must stress the very) slightly U shaped. I still think that the DX90 is more neutral than the Fiio X3 & X5 as well as the DX50.
 
 
Summary
 

telecaster's fantastic picture of the DX90 and his XBA-H3. 
 
Wow, we are finally here. I must say, if you have actually read this entire review, congrats. If you didn’t read the review, I will give it a brief summary over here. The DX90 is a huge improvement over the DX50 and if you are considering which one to buy, I would save up and get the DX90. If you are like me, you will want to upgrade a month after you buy a DX50 lol. Anyway, it is a little U shaped and extremely detailed and has a wonderful way of presenting music. I simply cannot recommend this DAP enough, for me it’s just perfect (well, almost). Once they clear up some firmware issues, this will be 5 stars for sure! If you have any questions or suggestions, feel free to comment or PM me. Thanks for reading this and as always, I hope it helped and if it did, I would really appreciate it if you could give this a thumbs up.  
 
Edit: Changed to 5 stars because newer firmwares have solved the UI issues. 

I'll skip all the usual nonsense and go straight to what matters - how does this thing sound?
 
I have just put the DX90 through a comparison test with all the appropriate gear I have. I settled on a track from a Sheffield Labs test disc to do the comparison, because it is a good recording and it has all the elements I listen for. Clear multiple vocals, lots of percussion and a difficult bass line. Sometimes the various elements are thrown together, and it takes decent kit to keep everything separate yet still musical.
 
The kit I have used is:
 

1. Westone 4R IEMs, I think they were about $400 (I guess this is most appropriate, given that this is a portable player and the W4Rs are the right kind of budget and are extremely revealing).
2. A Meier Audio Quickstep amp, $415.
3. Ipod classic 160Gb
4. Nexus 5 phone (playing FLAC).
5. iBasso DX50.
6. iBasso DX90.

 

 
The iPod and Nexus 5 were very similar in sound. Both are not bad at all, but both display quite a narrow sound stage, with the different instruments tending to blend into each other. Both had to be run at full volume to get normal listening levels and both had difficulty with the percussion. Bass drums were not that dynamic and the cymbals tended to mash into a "sound", rather than a representation of cymbals. The bass guitar was a bit muddled - definitely there but a bit concealed and muddy. If you have heard nothing but players on this level, you'd be quite happy.
 
Next the DX50 (without an amp). To get the same volume, only level 216/255 was needed. The DX50 is a noticeable step up, with a new level of clarity and dynamics. The vocals now sound like a person, and the instruments can all be placed easily. The cymbals are clearer and more pleasant - at first it all seems like a small step up, but the more you listen the more detail you can hear. Your music has taken a step up in clarity that makes you want to re-discover all your old stuff.
 
DX50 LO -> Quickstep amp. This is a major boost up. The sound signature is the same, the clarity similar (slightly improved), but the dynamics and bass are much better. There's a weight behind the music, giving it a more rhythmic feel, with the vocals more in your face and easier to separate from the rest of the instruments. You start to hear bits and pieces that before were slightly lost in the melee of sound. The bass guitar now is clearer, deeper and more precise, and the percussion has a much greater hit. Looks like the DX50 is slightly let down by its internal amp.
 
DX90 (200 hours burn time). The first few seconds sound similar to the DX50 with amp. But suddenly you realise how different your music sounds. The clarity and positioning of all the different tracks is astounding. Your music is now not a collection of sounds mixed together, but individual instruments playing with total clarity in their own little places in front of you. You hear fingering on guitars, breaths on vocals. Everything. And now cymbals actually sound like cymbals, not the sound we are used to hearing as a representation of cymbals. And for the first time, I could easily separate the vocalists into different people, as if you are right there. The bass guitar now sounds like a real bass guitar, not a synthesised bass note that you "know" comes from a bass guitar. The treble is so detailed, yet smooth and never too much. I can't get enough of it.
 
DX90 LO -> Quickstep amp. I have spent so many hours going back and forth between amped and not amped, and have finally come to the conclusion that unamped is fine. The quickstep adds punch and a touch of extra deep bass, but I reckon there's a tiny loss in staging in the treble. It's really hard to tell, but on that basis it's not worth carrying around an extra lump. Within 10 minutes you get used to either sound signature, so I plumped for the unamped DX90.
 
As a completely unrelated test, I compared the DX90 to an ODAC+Quickstep combo. The results are very similar, which gives me more faith in the ODAC than I had before. The bass clarity and punch are very similar, but if anything the DX90 has the tiniest edge with the treble and the staging - the positioning of sounds is just a tiny bit better with the DX90. Really there's not much in it.
 
All in all, I am extremely satisfied with the DX90. But the caveat is that you need really good headphones or IEMs to make the most of it - you can't expect a huge step up if you use "OK" phones. I have tried all of the above with my Philips X1's, and the differences are not nearly as obvious. The X1's sound nice, but are simply not detailed enough to extract what the DX90 is outputting.
 
The UI doesn't get in the way of the music, the touchscreen makes browsing and finding quick (I use folder mode, not database), it's reliable and well made. And the huge hardware buttons are exactly what I need/like.
 
The only potential downer is the 6 hour battery life. This is no issue for me, because I never listen more than about 4 hours away from a charger. So to me it's a price worth paying, as is the $440 asking price.
 
In short, I love it!

Hi everyone.
 
Not so long time ago I bought IBasso DX90, now I feel necessary to review it for other people not to repeat my mistakes.
 

A Little Background.​

I’m 23, during my teenage portable electronic devices were actively evolving. I remember my first IPod Nano with a lot of memory (it was 1Gb). For me it was really cool to listen to music outdoors with that much comfort. Then first cell phones with 3.5mm jack were appearing, evolving, offering more memory, more comfort. I was changing IPod to another IPod, another IPod to phone with audio jack, then to better one. But also i was changing IEMs from cheeper ones to more and more expensive. At some point I came to buying quite expensive earphones and for me it wasn’t enough anymore. I wanted better audio quality, so I decided to buy Hi-Fi DAP. I read a lot of reviews, was doubting between options, but, finally, I read about new model of IBasso with pretty serious hardware and good vendor reputation. I read first extremely positive feedbacks and pulled the trigger with DX90.
http://i62.tinypic.com/333iz2h.jpg
http://i61.tinypic.com/2lddfp.jpg
 

Build Quality.​

Build quality is good, device is solid. DAP itself is not large and can easily feat jeans pockets. Design is universal, I like it far more than other «audiophile» DAPs. 
 

Firmware/UI/Usability.​

It’s not that much good. Menu is very simple and easy to use. But sometimes it’s too uninformative and uncomfortable.
 
Just to give you an example: 
1. Some buttons on the screen are hard to tap because they are too small.
2. When I start playback and see playback screen (with song name, progress, cover) there is no way to know what is the number of current song in playlist/album and overall number of songs.
3. When I plug DX90 to my PC for battery charge there is no way to know charging progress, UI simply shows that my player is connected somewhere via USB.
 
Actually, there are big amount of issues with UI, some of them are quite significant, but I won’t criticize IBasso for that because when I was paying $400 for DX90 I knew what I’m going for. Main point that drove me to buy this DAP was sound quality, otherwise I’d go for some another IPod.
 
But DX90 has also some critical bugs that make using player really uncomfortable, hope IBasso won’t be too lazy to fix it. In general UI responses quite OK, touchscreen scrolling speed is acceptable.
http://i59.tinypic.com/idf9lx.jpg
 

Sound, Part 1.​

This is was that all was about. I was ready to carry separate device, risk to loose it, synchronize music in not the most convenient way, live with all this poor software and short battery life. It was all about sound.
 
My current IEMs are Astrotec AX60. Most of the time I was listening DX90 with them. Also I had long auditions with Sennheiser IE800 and Sennheiser HD25-2 (80 Ohm version). Briefly I was listening DX90 with German Maestro GMP400 and Vsonic Gr07. Neither of this headphones gave significantly different sound from DX90 comparing to my Macbook Pro.
 
So I brought DX90 home, copied my most favorite music there, turn on and… hear nothing special! It was absolutely ordinary sound that may be produced by any smartphone or IPod. I was a bit messed, but decided not to panic but to play around with it. I tried different headphones (my IEMs, another IEMs, big headphones, high/low impedance headphones), amplifier gain settings, but still nothing. I tried DX90 to play different formats: MP3, AAC (m4a with 256 kbps), ALAC (m4a with 600+ kbps), FLAC, APE, 24 bit recordings, but still nothing. 
 
Then read IBasso claims about DX90 needs 400 hours of burn-in. Of course all this «burn-in»’s are lies but player is already bought, money are paid. I had no good sound and definitely nothing to loose, why not to try it? So I tried. I was charging it and leaving to play music (mostly overnight) with burn-in cable, then trying to make short listening sessions between cycles to find some positive shifts. Now I have about 40 hours of burn-in, but still nothing. At this point I’m coming to conclusion this is final sound of IBasso DX90 and I’m ready to describe it.
http://i57.tinypic.com/33kryfa.jpg

Sound, Part 2.​

I’ve never heard Fiio X5 or Hifiman 802/901 or other audiophile players, so I will compare DX90 to Sandisk Sansa Clip, recent smartphones, and my Macbook Pro 2011. First thing I’d like to mention: IBasso DX90 is NOT Hi-Fi player. I know it because I have some background in desktop DAC’s and amp’s and I know what real High-Fidelity sound is.
 
DX90 produces neutral sound, it has no coloring. 
 
Bass:
Bass is present but neither boosted nor suppressed. It is not deep and doesn’t have good attack or impact. Sansa Clip, iPhone or IPod Touch have very similar bass.
 
Mids:
Also neither forwarded nor recessed and also very similar to Sansa Clip or Apple products. Music is flat, sounds have no third dimension, details level is low. I can’t hear with DX90 details that I don’t hear with my laptop or Sansa Clip. Sometimes I feel some details more audible comparing to Macbook, but after intensive comparison I understood: it’s not about higher resolution, it’s just about slightly different sound signature. Some details sound lauder (and getting more audible) on DX90, some details, due to different signature, are lauder on my Macbook. 
 
Highs:
DX90 has really sharp treble. For me it’s a double problem because I have IEMs with sharp treble as well. I tried to pair DX90 with headphones without emphasis on highs, but treble is still harsh on high volumes. Usually it wasn’t problem for me all because all normal players have equalizer. When I feel some specific headphones or recordings too harsh I just suppress highs for a few DBs and things are getting right. 
 
IBasso doesn’t have the equalizer, there is salvation from harsh sound. The only thing you can do is to pair it with headphones with suppressed highs or to listen music on low volume levels.
 
Soundstage:
This parameter is usually more headphone-driven rather than source-driven, but, anyway, DX90 hadn’t widen soundstage for a tiny bit comparing to Macbook. With my own IEMs I get all sound inside my head playing in one single mess with a very few space between sounds/instruments. This «soundstage» stretches from ear to ear, some particular sounds on particular recordings are getting positioned slightly beyond ears. Absolutely the same results I have with my Macbook.
 
Overall impressions about sound:
Player doesn’t perform main thing it was designed for and people are buying it for: it doesn’t play music better than ordinary gadgets. Furthermore, if i would slightly adjust equalizer on my Macbook (sharp up highs a little), DX90 and Macbook would became totally indistinguishable. If to talk about my own personal preferences, I prefer gadget like HTC One over DX90. It has more soft sound that feels more volumetric. 
 
Comparing DX90 to desktop Hi-Fi DACs&Amps is irrelevant. True Hi-Fi sounds like music flows from somewhere under big pressure, like it’s has a lot of power and is very massive. Also on good Hi-Fi I have the illusion like music is not getting emitted from headphones, it is levitating around my head, creates stereo panorama. Music itself is very tight, feels like there’s more music in music. Listening it for a first time is like a magic. IBasso DX90 not just doing all this things not good enough, it’s not doing it at all!
 

Overall impressions about player.​

They are so: IBasso DX90 is weird. Hi-Fi DAP without audio settings and equalizer is weird, doesn’t it? Furthermore, DX90 is Hi-Fi DAP without audio settings, and equalizer, AND SUDDENLY HI-FI SOUND!
 
Turning back to equalizer, this is equalizer:
http://i62.tinypic.com/vpx05w.png
 
This is not the equalizer this is SHAME:
http://i57.tinypic.com/jqj88x.jpg
 
Audio playback in DX90 is also weird. Back, forward, and Play/Pause buttons have 2 seconds delay. It means software player has 2 seconds buffer. I have no idea why it was done that way, it doesn’t improve sound quality somehow, but delivers read discomfort while use.
 
Those built-in «equalizer» is also weird. Beside the fact you’d have no ability to adjust sound with it, turning it on makes sound quieter. I thought it was done for those who are going to increase volumes in eq. bands, it would lead to sound quality reduce. But no, when i turned all bands up, sound quality was reduced on quieter sound as well.
 
Also another interesting fact: you may have problems when listening music outdoors with DX90 in pocket. When I tried to do so, sound in both ears (sometimes one) was getting disappeared rather often (1 time per 15-30 seconds) and returned back. My first thought was I broke my IEM’s cord, but no, this is DAP issue. Also sound wasn’t disappearing/appearing-back instantly, it was smooth. However I never get this problem at home even when I’m shaking player in my hand. Also I never get this problem using another IEMs.
 
My assumption of a problem: I have 12 Ohms IEMs, player while being carried in pocket under some stress on audio jack «feels» too few resistance and «thinks» there is no headphone plugged in. So it cuts off audio jack electrical current supply for 1-2 seconds. But its only assumption, I may be wrong. However I never experienced this issue with 16 Ohms IEMs, maybe because of higher impedance, maybe because those IEMs have L-shaped jack that makes less physical stress on DAP’s audio output.
 

When IBasso DX90 may be really useful.​

DX90 has very narrow use. It has more powerful amp comparing to other DAPs, so if you lack volume level on your smartphone or IPod, IBasso DX90 may be the option for you. But I barely can imagine such case, because smartphones usually have enough power.
 

Why I wrote this review.​

IBasso DX90 has obsolete CPU and display, poor firmware, nothing really expensive. Additionally IBasso were forced to install rather expensive audio chip, because of marketing, otherwise they wouldn’t sell it. All such devices usually supported by creating panicle euphoria on forums with target audience. 
 
Later, a lot of people are writing reviews with the same fancy words: «black background», «soundstage», «intimate vocals», «price winner» and so on. (By the way, all devices are getting reviewed by the same people, and that’s probably what they do living.)
 
In result devices with cheap components and $440 price from no-name vendors (IBasso doesn’t spent money on advertising, marketing, research, maintaining stores around the world like big companies do) have complete sold-out of first parts on preorder stage. 
 
It’s not just about IBasso made bad device. I don’t think the situation would dramatically change if I’d buy Fiio X5 instead of DX90. But anyway, I bought DX90, so I’m reviewing it and do think IBasso don’t deserve to earn money on this device.
 
 

Verdict.​

I wrote this review for people like me.  I can’t say there is no portable devices with really high sound quality. To claim it I need to listen to all «Hi-Fi» DAPs, but I listened only DX90. However, I would recommend you to save your money. You wan’t to have a good sound? Buy yourself desktop DAC+AMP. For the price of HiFiMan 901 you can buy really good combine. Outdoors just enjoy your music from your smartphone.
 
 
UPDATE:
I have no permission to comment my own review (or I just don’t see «comment» button), so I update the review itself. 
 
I will probably surprise a lot of you: I’m not going to conquer the World with my outstanding reviews. Also I’m not native English speaker, my English is far from being perfect, so my text may be, somewhat, hard to read. Well, I’m sorry that. 
 
I’m not professional but I write what I think(hear), nobody pays me money for that, so I think my review has value. I bought DX90 and felt huge dissonance between what I read about it and what I hear from it. That’s why I wrote this review. Or you think if I registered few days ago, I’m not pureblood enough to write user reviews? If you have advises how to improve it, write something in more details - it’s alway welcome. But what arguments you expect me to provide? I say: there is no soundstage. What arguments can be here? You believe me or don’t believe me, but what arguments? You expect me to come to you house and organize you blind comparison DX90 vs. Macbook Pro or what?
 
I already mentioned headphones I was listening DX90 with. I should’ve done it at the the very beginning. I’m sorry for that too.