A Survey of Digital Audio Players Part 3 iBasso DX90


iBasso DX90 ($399)
Way back 2012—an eternity in this market—iBasso was an early bird in the high-end DAP game. Their DX100 was, for its era, a shockingly large and expensive portable player. In many ways it was ahead of its time; it ran Android, had a top-shelf ESS Sabre DAC on board, and relied on a touch screen when most others did not. Unfortunately it also cost over $800, which felt like a huge sum back then; had poor/unpredictable battery life; ran overly hot; and had a host of operational quirks arguably rising to the level of "bugs". Some of these issues improved via firmware updates but generally speaking I was not a fan of the DX100.

Several years later the company gave us a more affordable DX50. I used one in the early days and it ended up costing me an expensive set of custom IEMs when a firmware bug randomly set volume to full blast. This proved too much for sensitive balanced-armature drivers, and down went around $950. That made for two rather disappointing releases in a row and from that point onward I was done with iBasso. That is, until I heard overwhelming feedback on their DX90, calling it a fully mature, highly competitive device—maybe not initially, but it matured over time and was now ready to go. I reluctantly gave it a chance and I'm somewhat glad I did.

External Design
The DX90 is on the smaller side compared to many others here, but still isn't truly compact like Sony's A17 or the Sansa products. Its brushed aluminum construction—or is that really plastic?—seems to be of acceptable quality, though doesn't compare to the ZX2, Cayin N5, A&K players, or even the more affordable Fiio models which manage impressive builds. It's got a 2.4" touch screen but also makes heavy use of the large dedicated buttons placed just below the display. Resolution is only 320 x 240 which sounds bad but really isn't all that terrible on a screen of this size.

The light weight of the DX50 initially made it feel cheap (because audiophiles know weight equals quality) though after some use I came to appreciate the way it disappeared in a pocket where heavier DAPs could not. It ships with a silicone case that isn't what you'd call attractive but does a great job keeping the device free of scuffs during regular use.

Overall nothing amazing here, but it does keep pace with the similarly priced Pono. Despite the light weight, or perhaps because of it, the device stands up quite well to being dropped, and my review loaner looks good as new despite frequent haphazard use.

Internal Design
iBasso packed plenty of good stuff in here. While their original DX100 used the ES9018S Sabre DAC chip—normally found in full-size home components—the DX90 is centered around a pair of ES9018K2M DACs running in dual-mono mode. These are physically smaller chips which draw a lot less power, making them better candidates for a DAP. Output stage is based on a pair of TI OPA1611 opamps with BUF634 buffers for substantial output. iBasso claims their device can swing some very respectable voltage and from my listening I don't doubt them.

Volume control is handled in the digital domain with a total of 256 steps. I don't know the exact increments between each step but it has to be quite small; it takes more time than usual to go from quiet to loud. This can be an inconvenience once in a while but is ultimately a good thing—it guarantees the ability to dial in proper levels regardless of the headphone being used. A three-way switch for low, medium, and high gain seals the deal, along with an output impedance well under 1 Ohm. From a technical perspective, this thing really does work with pretty much any headphone.

The DX90 handles all the major file formats and goes up to 24-bit/192kHz for PCM material. It didn't support DSD out of the gate, but a firmware update eventually unlocked that feature. It now handles up to DSD256 though iBasso says it converts everything to PCM.

Behind the scenes is a dual-core ARM Cortex A9 processor running at 1GHz per core. It's perfectly adequate for the job and I suspect anything more powerful would just be wasted in this particular application.

User Interface
There's actually an older version of Android underpinning the custom UI. You'd never know it based on appearance though and there's no ability to run apps. Controls are handled through a combination of touch screen and physical buttons. In many cases these features are duplicated so the user can do whichever feels more natural. I find that I do a bit of both. The touch screen gets the job done without being the most beautiful thing out there. It's responsive enough and that's what matters most. iBasso lets users change background wallpaper if that sort of thing matters to you.

I've seen a lot of complaints about buggy firmware on the DX90. Due to my prior iBasso experience I was very careful to watch for issues, and so far the only thing I find is the so-called "gapless" playback not being really gapless. It's a small gap, but it's obviously there and for some music that's very annoying. Other than that the firmware seems solid these days; complaints must have stemmed from earlier versions.

Overall the experience is what I'll call "adequate" at best. Much like a Toyota Corolla, it gets the job done without a hint of excitement or passion. But hey, there's another way to go, a way which will feel very familiar to a lot of users out there: Rockbox.

Rockbox lists the DX90 as being an "unstable" port, but I've been using it for a while without issue. Go here to download, follow the install instructions, and you should be up and running within 5 minutes. This particular install gives a dual-boot setup so you can always go back to the original. Something I rarely do unless using the USB DAC option, which doesn't work with Rockbox. Also for higher resolution tracks since Rockbox downsamples all to PCM Redbook quality.

All the usual options are here: Crossfeed, EQ, bass and treble boost, balance adjustment... everything you've probably come to know and love if you've experienced Rockbox on another device. And the gapless playback actually works as it should. To me, it feels like home, and is a huge benefit on this otherwise mediocre user experience.

Despite its smallish stature, the DX90 has a lot going on in this department. Aside from the expected headphone jack there's also a line-out jack and digital output. They all come in 1/8" form; a bundled adapter provides a usable coaxial digital connection. The DX90 can also function as a USB DAC using its microUSB port. This covers most of the connectivity bases aside from wireless streaming which gets no love here.

One gripe, the headphone and line-out jacks are next to one another on the bottom panel. This creates a very real possibility of accidentally plugging sensitive headphones into the wrong jack—which would not be pretty. The digital out gets placed on top of the device away from the other two jacks, and I can't help but think this could have been planned better.

For storage, the DX90 ships with a paltry 8GB expandable via microSD. I ran a 128GB card without any trouble. That internal memory is tiny but I suppose better than nothing. I keep some old favorites and reference material on there since I go back to that stuff so frequently.

On the plus side iBasso takes the unusual step of giving us a replaceable battery. Their chosen battery is the same as the Samsung Galaxy S3 so replacements are easily sourced.

The downside is that performance is nothing spectacular. They list it as 14 hours on their site but I only got 8-10 during regular use. Perhaps the 14 hour figure is achievable playing MP3 tracks which require less horsepower than FLAC. While not impressive, neither is this worse than the AK100 II or any number of other DAPs.

Sound Quality
The DX90 is a surprisingly enjoyable DAP when it comes to sound quality. $399 gets you clean, detailed sound with enough juice to drive most headphones comfortably, and I appreciate the lack of hiss with sensitive IEMs. The sound is a bit on the analytical side, which is either welcome or mildly annoying depending on the music and headphones involved.

Positive examples: The AKG K7XX sounds terrific with the strings of cello-rock outfit Break of Reality. There's plenty of detail and bite, with very well defined leading edges and very little glare to speak of. This is a much better result that what I recall from my original K701 which seemed a lot more "splashy" up top and thus wouldn't be a good match for the DX90. The HD650 is also driven exceptionally well...almost unbelievably so for a compact device like this. I sense no strain at all, and again the highs and upper-mids are sharp without going overboard on Chet Baker's fabulous live album "Chet in Paris". Imaging is very precise though I do find the soundstage a bit unrealistic for some reason. Maybe too much width and not a corresponding sense of depth. Low end impact is pleasing if not up to the high bar set by the ZX2—again, no shame in that based on price.

On the flip side, I didn't care for the DX90 nearly as much when using my Grado PS500 or Ultrasone Edition 12. Especially when meandering through the (rather large) portion of my catalog consisting of mediocre recordings. From Jimmy Eat World to Wynton Marsalis, no artist is immune from at least the occasional poor release, and the DX90 is has a low tolerance for these types. Recordings with deliberate zest combine with peaky headphones to make an overall unflattering result, and the DX90 is clearly not helping the problem. In these cases I vastly prefer the warmer, more relaxed presentation I get from the HM802, Calyx M, or Pono devices. Even Grade A material like the Reference Recordings HRx releases of Respighi, Stravinsky, or Rachmaninoff can be a bit overwhelming on these headphones when played at higher volumes. Stick with more neutral or darker headphones though, and you'll be rewarded.

Using the DX90 with the line-out feeding an external amp, the result is much the same. Which tells me it's got a fairly neutral amp section, and the character involved is due to the DAC portion of the design. The DAC is very nice in the right context though, using line-out to the $599 Arcam rHead desktop amp produces stunningly articulate sound, as long as one stays away from certain brighter headphones.

All in all I do very much enjoy the DX90. No doubt it has limitations, as does every DAP here if I'm honest, but they seem manageable enough. The DX90 sets you back far less than the expensive competition and really isn't far behind many of them—in some cases it meets or even exceeds its counterparts. I'm not sure how long iBasso will keeps this model around but it's definitely worth considering.

tony's picture

This is one hell-of-a-summary!

Battery life, efficiency, Streaming, Quality, Design Integrity, you're hitting all the key points. What do I owe you for this? Buying the wrong feature Set is an expensive mistake.

Can you offer an opinion on the New Phones as Audio Players? the V20 for example.

It would seem that the World will be using their Phones as DAPs, I hope to encourage you to continue your "important" work in this new area.

Thank you for all this work!

Tony in Michigan

John Grandberg's picture

...are getting better (at least some of them). Unfortunately it seems like LG and others don't want to bother with us lowly audio journalists. I have a heck of a time getting replies from their PR people, which makes it tough to properly investigate. I'll keep at it though.

I'm currently using a ZTE Axon 7 as my daily driver and it's pretty impressive, both as a phone and in terms of audio quality. Not a true "DAP replacement" but very impressive for what it is.

flohmann's picture

A big omission, it seems to me, since the X1a is about $650, supports up to 400gb, and runs a newer version of Android than the Sony player (so runs all the apps that the Sony player does). Maybe Part 4?

John Grandberg's picture

I had the original DP-X1 when it first came out. Weird battery issues, and then the 3.5mm jack went sideways. I figured it was just an anomaly, but then a friend with a pretty decent measurement rig got some wild results with his DP-X1 - *extreme* deviation from the published specs. Those two experiences were enough to put me off when it comes to Onkyo.

Don't know if those issues are still present with the DP-X1a, and honestly I haven't kept up with it. But from now on I'll be doing updates one DAP at a time so I should manage to be more nimble going forward. Perhaps an Onkyo is in my future one of these days.

logscool's picture

I also had issues with my original DP-X1 and almost didn't get a second one after trying the not very good OPUS#1 I went ahead and got a second DP-X1 I've had no issues with the new unit. There is a pioneer unit coming out that looks to be identical (XDP-300R). There is also the single ended only version Pioneer makes (XDP-100R).

Meshail's picture

Why do you find the opus #1 bad or ( not good ) where is it lacking, I'm asking as I want to grab one now as price is like 290$ & you are the second person who is saying it is not good

logscool's picture

It just didn't have a lot of weight or dynamics to the sound pretty "digital" sounding in comparison to better sources. If you have a chance to try it then definitely try it as you might like it's signature.

Meshail's picture

Can you please suggest me a better dap in the sub 300 $ range as the opus#1 runs for 289$ on amazon

Long time listener's picture

I note you mention the Fiio X5, but they now also have an X7--disappointed not to see it as I would appreciate comparisons. I trust the Fiio brand, they use a good DAC chip, and the sound seems very good at the $600-700 range. But is there better?

Also, to Tyll, a review of the new Shure electrostatic IEM would be appreciated. Thanks

John Grandberg's picture
See, there's the dilemma I mentioned - always another worthy model coming out. I finally had to put my foot down and just go with what I had, else it all became irrelevant. But I definitely intend to catch up on newer models from Fiio, Cayin, Astell&Kern, and perhaps the new Sony models. One at a time though!
thefitz's picture

I use the DX90 because you can plug in a USB hard drive via OTG. Use Western Digital drives. 2TB+ at my fingertips!

John Grandberg's picture
The literature for the Acoustic Research M2 also mentions the same OTG functionality. I never actually tried it but I can see how that might come in handy in some cases. Thanks for the info!
jcheadphone's picture

Thanks John. Really enjoyed reading your three part series on DAPs. I used to own the Calyx M and agree it sounded wonderful. I ended up selling it because of the shortcomings that your mentioned and others. I currently own a ZX2. It sounds great and is able to drive all my headphones from my Shure SE846 to Audeze LCD-XCs with good results (although the XCs as expected certainly benefit from a desktop headphone amp). I also picked up a pair of Sony MDR-1000x wireless noise cancelling headphones for travel. The LDAC streaming with the ZX2 sounds very good. In A/B tests with 16/44 ALAC and FLAC tracks I can't distinguish a difference between the wired connection and the LDAC wireless streaming. I note that Sony has now made LDAC available on the licensing market so maybe we'll see it on other non Sony Bluetooth products in the future.

Three Toes of Fury's picture

As a big fan of better quality sound on-the-go, the ever evolving DAP market is of big interest to me. I very much appreciate you taking the time to review so many entries. Its great to see this site evolve in its review and wall-o-fame offerings.

Great stuff...keep it up...even if you dont do the huge comparison reviews (takes loads o time im sure), drop in with a 1-off review of a DAP every now and then. Would be much appreciated

Peace .n. Living in Stereo


GlennT's picture

I own a Questyle QP1R and I love it. However, I agree that the scroll wheel's functionality is disappointing. Before I bought the QP1R I had the expectation that the scroll wheel on it would be as useful as the old iPod scroll wheels used to be, but that's not the case. I find that the touch-sensitive buttons around the outside of the scroll wheel as well as the button in the center of the wheel become usability obstacles when scrolling. It's too easy to accidentally brush against the touch-sensitive buttons when scrolling. It can be very frustrating when trying to scroll to a specific selection only to suddenly be dumped back at the home screen because your finger accidentally brushed against one of the touch-sensitive buttons surrounding the scroll wheel. The wheel is also pretty slippery, making it sometimes difficult to grip. However, they have an adhesive film that goes over the scroll wheel that Questyle will provide to you upon request at no cost that mostly solves this problem.

husafreak's picture

I am a huge fan of my QP1R. It is beautiful and sounds fantastic. Clean, dynamic, and detailed. Your review is on the money. I would say that the scroll wheel cover is a must to facilitate its use. I believe the unit ships with them now but they are free and easy to get, actually something as simple as a generic stick on rubber dot can solve this design flaw.
I use mine with a set of 64 Audio U6's, TH-X00's, and now Mr Speakers Ether Flows. It is amazing to me how much detail and life I can hear with the Ether Flows. I had to comment because my son is a drummer, a professional now, and so I really get into the nuances of drums and cymbals. I swear I could hear the double bass chain mechanism rattling away when I was auditioning the Flows through my QP1R! I look forward to hearing the Spark album you used in your review.
By the way there is a very active QP1R thread on the Head-Fi forums and the company has been very proactive in releasing timely updates. In only one year they have solved many requests.

John Grandberg's picture
...for the comment. Glad you are enjoying the QP1R. The firmware aspect is yet another category which I probably could have used to judge each model, or at least each brand. Questyle is indeed one of the better ones in terms of frequent updates.
Jayhawklaw's picture

I love comparisons like this. I hope you (and your sister publications) do more. So much more meaningful data for the "everyman." I would love to see a similar survey for portable dac/amps (e.g.: Audioquest Dragon Flies Red and Black, Oppo HA-2SE, Chord Mojo, etc.)and how a smartphone with one of said dac/amps connect compares to the dedicated DAPs.

jcheadphone's picture

At first I was disappointed that Sony decided to go with a proprietary WM port rather than micro USB. When I contacted Sony tech support via phone to ask about this the tech rep said the WM port was intentional because it allowed the left and right channels to be separated for optimum line out sound quality. Don't know how much this explanation holds water but thought I would mention it.

John Grandberg's picture
They say the same thing about their 3.5mm jack. Not sure it really makes a notable improvement of any sort in terms of SQ, but it's a perfect example of Sony being Sony.
Martin.'s picture

The only DAP that seems "consumer friendly" in my eyes is the Sony NWZ-A17, which is priced at 300$. Is it even worth buying a DAP for 300 usd when you can save a bit more for a mojo at ca 500? The real question being, other than portability, what advantage would a 800$+ DAP have over a 500$ portable DAC like the mojo and, most importantly, would it make a discernible, audible difference? Thanks for any answer :)

John Grandberg's picture

Different folks will have different priorities, and each solution has pros and cons.

I like a dedicated DAP because it's smaller and easier to manage than a phone-plus-Mojo type solution. Also many phones don't have expandable storage so a DAP with 128GB or 200GB (or more) can be useful if your phone is stuck at 32GB or even 16GB. If we're talking Sony ZX2, then battery life is supremely better than a Mojo. Last but not least, there are various sound signatures to be had with different DAP models. Not everyone loves the Mojo presentation, as popular as it seems to be. The target market who prefers the sound of a Cowon Plenue 1, for example, is not likely to be thrilled with the Chord.

On the other side, it could be argued that you always carry your phone with you anyway, so a DAP isn't really saving any space over a Mojo setup. And a decent phone is usually superior when it comes to display quality, ability to run apps, etc. In some (many?) cases the Mojo sound will be superior depending on your criteria.

I agree that there aren't enough affordable options right now. I'm still looking for a true replacement for the Sansa Clip/Clip+/Clip Zip. Only reason I can't put those on the Wall of Fame is the fact that they are long since discontinued.

Martin.'s picture

Thanks for your answer. Being a novice, I usually want a "this is best" answer because I feel I need to be told what is best by veterans in the field. It is nice to be reminded that audiogear is personal and that "different strokes for different folks". Your well balanced answer is much appreciated.

br777's picture

has convinced me yet to give up my sansa clip zip.

Rblnr's picture

Very comprehensive and useful reviews. I've been using the Plenue 1 for a couple of years after testing it against others at the time of purchase and am still very happy with it driving JH Audio Angies and some over the ear headphones as well. Surprised that Cowon doesn't get more attention. The sound is as described, smooth and easy, but by no means lacking dynamics micro or macro. Sometimes I want a more 'in your face' sound and the BBE and other profiles ( as noted in the review) can provide that to a point.

I also have to say that I have little tolerance for wonky interfaces anymore -- time for those manufacturers to enter the 21st century, whether or not interface is really their expertise. The Cowon's ergonomics, while perhaps 'merely' utilitarian, are at least direct and unfussy.

Peragulator's picture

No love here for the X7 I see.

John Grandberg's picture
I just had to stop accepting or seeking out new models at some point, or else I'd never get this thing finished. I intend to revisit different models from time to time, so a Fiio of some sort is certainly on the horizon.
Trebor74's picture

Hi, great review! Are there, or will there be, any measurements available at some point to complement the reviews? I'm especially interested in the Cowon measurements - Cowon and a couple of other sites have posted THD figures for the player but these are probably not with any load. I'm curious to see how well it performs (in terms of THD both in earphone and headphone modes) on some low impedance cans. Thank you!

Peragulator's picture

AK300 ($899.00) Sony 1a ($1,199.00) FiiO X5 3rd gen ($400.00) Pioneer 300r OPUS #2 ($1,400.00)

yc627's picture

I'd Love to see some flagship phones' real world comparison in their ability to reproduce sound through headphones... Such as:

Sony Xperia XZ premium: they say it can do 24bit 192kHz audio. And Sony's own LDAC bluetooth codec. How does it sound like with Sony h.ear go SRS‑HG1 bluetooth speaker compared to other devices... + Sony Xperia Z series and to the XZ lineup, they had this noise cancelling earphones that needs no battery boxes like the Sony MDR-NC750 and MDR-NC31E I also wonder what you guys think about those earphones.

Samsung Galaxy S8: I hear it can do 32-bit/384kHz audio and I wonder what audiophile people would think about that.

LG V10, V20, V30: I heard they got 32-bit/192kHz audio and B&O Play certified. LG seems like they don't really do a lot of marketing on the audio parts what do you think about the B&O Play certification?

Just a question from a college student who is somewhat regretting getting a Sennheiser Momentum 2.0 just because it had a huge discount on Amazon and is thinking that I should have gotten the V-Moda M100 or Sony H.ear on MDR100ABN or just go crazy and go with Sennheiser Momentum Wireless...

trl's picture

Based on https://reviewzorro.com/wp-content/uploads/2017/08/HifimanHM901s3.jpg seems that Hifiman 901S has 2 x ES9018S inside. Quite impressive, so that explains the price indeed.