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HiFiMAN HM-901

  • Hifiman DAP featuring dual ES9018 DACs with swappable amp modules.

Recent Reviews

  1. Mshenay
    Classic Hifiman House Sound Perfected!
    Written by Mshenay
    Published Oct 31, 2014
    Pros - Spacious Sound, Power, Modular Amp Cards, Mircodetail, Taut Bass,
    Cons - Build Quality, Battery Life
    A big thanks to Drew and every one at Moon Audio, they handled the sale of this new unit to me and were very helpful in answering all of my questions! 


    Ever since my Hifiman HM 601 back in 2012 I've always loved the Hifiman Sound. The deep bass, the smooth mids and that spacious presentation. Ideally for me I thought the Hm 801 was going be the end all Hifiman DAP for me. How ever I was seeing that the unit did not age as well as I was hoping it would. In addition after spending a year with out it dawned on me one day that it was just a touch to slow, and warm for my tastes. It had that classic deep bass and spacious sound, but just wasn't fast enough. Most of my headphones sounded better out of my NFB 10ES2 so I knew it was time for an upgrade! 

    The Box 

    Coming from the Old HM 801 Box I was at first glance a little disappointed, the box for the HM 801 was a perfect compliment to the player it self. It was gawd awfully large and accented in gold, how ever it felt a little cheap in the hand. The HM 901 box was little different. While it didn't have the same BIG PRESENCE, like the HM 801 did it had a better feel in the hands. Felt a little sturdier and have a nicer set of textures and materials on the outside as well.
    Of course the interior of the two units was pretty much the same, Charging cable, the unit it self and with the HM 901 the RCA Line Out Cable as well. 
    The player is smaller than I expected, which was a nice surprise!​
    Simple clean presentation! ​

    The User Interface 

    I spent about all of 3 mins with Firmware Version 1.083, I then upgraded to the new Taichi 2.01 Firmware, and I must say that I enjoy it! Sadly It's only frozen on my once... in the last 20 hours of use. Which is about right for a Hifiman DAP... I found the User Interface to be easy to use though most of it commands were easy to figure out. ​
    Some of the more useful commands were not so easy to figure out, though maybes that's just a user error on my part ;3​
    Either way the complaints of a poor and Buggy UI weren't present in this new Taichi 2.01 interface and I was happy to find that! ​

    Build Quality/ Utility 

    And here is the ugly side of this new unit, as much of a fan of the HM801 Body and Build as I was... I was disappointed with how the HM 901 is built and how it feels in the hand 
    The buttons feel about as cheap as they look, the Center button looks and feels really nice! How ever the scroll wheel... is a disaster. It's a touch un responsive, nothing like a smooth an light weight... say iPod Wheel?   The 4 Buttons on the side... feel like a wasted effort, I would think [going back the iPod seeing as they went for that] why not put in a bigger better quality wheel and use it's 4 main axis points for buttons, if your going to remind me of the iPod design you should REALLY live up to it!​
    Though there is rumors of a Hifiman HM901S to be out soon, apparently us HM901 users get to look forward to a "free" upgrade to a new chaise... we'll see how that goes when it arrives​
    And the BATTERY LIFE is standard, no better or worse than other Hifiman Player I've ever owned!​
    Though I'm not a fan of the Line Out... again it's iPod Esque with this BIG multi pin port. My issue with it is it doesn't grip the connector that goes into to well, that and the connector it self is odd... it terminates to the Left? That and while the Wire coming out of it is nice... the port it self looks and feels a little cheap... my iPod LOD has a nice series of locking metal grooves...​
    Yea that's two cables there... I would have really preferred the old HM 801 style Line Out [you know the 3.5mm kind] that way I could still listen to the player Line Out while I charged it! 
    SO let's hope Hifiman gets build quality up to par with the HM 901S launch! 
    All of the vanity aside ... I bet your wondering HOW IT SOUNDS!
    Well in Short it sounds GOOD
    All in all, I found that with transparent headphones or some of the brighter and more revealing headphones the HM 901 proves to be a great dac for these units,  The HM 901 being, dark spacious and very energetic,
     dynamic changes and imaging on the HM 901 take the cake for sure!​
     The HM 901 brings a great level of detail, space and speed to the classic "fun" Hifiman Sound. It is the perfection of the Hifiman Sound I came to love in my old HM 601 and HM 801 units! 
    It's a very transparent DAP, it's un forgiving of colored headphones, and poorly mastered tracks, though it still has some personality of it's own! Bass that's just a smidge boosted without ever being bloated and a very tactile and dynamic presentation! 
    An what I love about the HM 901 is not only does this sound exist in the Line Out but also with the Included Classic Card! I have a dinky little pair of MS1i-W's that sound GREAT out of the 3.5mm out! While I tend to use these headphones on the go, such as walking around campus or even hanging out at the mall, the HM 901 offers both the Hi Quality sound out of it's line out but also offers a great quality out of the Classic Card as well! While the Line out is better, the some what awkward plug don't always make it the most practical choice, that and my pockets are only so big! Still if your looking for an All in One Box Solution the HM 901 is where it's at! An if your like me and you just want to slap a line out into the sucker and run it into your portable amp it's going to offer a top quality sound there too! 
  2. piksnz
    Hifiman HM-901 Video Unboxing and Review
    Written by piksnz
    Published Sep 16, 2014
    Pros - The sound coming out from this device is magical, modular approach with different amp cards
    Cons - Buggy UI, Hardware scroll wheel not so responsive, Bulky and gets heated
    Hi All,
    I have done a video review of Hifiman HM901.
    Thanks for watching :)
      ToulouseLautrec, Vartan and Tail like this.
    1. View previous replies...
    2. 514077
      Thanks for your help.  Couldn't find the link on this page.  Thanks for sending the youtube link.  I enjoyed the video; you explained the HM-901 so I could follow it without being able to see it.
      Look forward to hearing other reviews as you do them.
      514077, Oct 4, 2014
    3. Skooter
      Piksnz - thank you for posting this very informative video. I have demoed the 901 at least a dozen times and found your video to be on point. Factual and credible.
      I am pretty sure I have heard all the major DAPs and I think the sound quality of the 901 is in a different league. I think HiFiman put all their effort into the sound quality and it shows. I intend to purchase the 901s when it is released.
      The 901 is physically large and the UI is clunky. I also noted the software tended to brick, although maybe the new software is more stable. 
      Skooter, Nov 9, 2014
    4. gapianca
      An object that should cost $ 300.00
      The sound is good, but not in keeping to product price.
      construction and qulity of materials ... really bad.
      The battery has a very limited duration.
      The HM-901 has a very limited versatility.
      The HM-901 is a very bad product.
      the assistance of the parent company is unseemly.
      Hifiman HM-901 was a big disappointment
      gapianca, Apr 22, 2016
  3. 00lunar
    REVIEW: Astell&Kern AK120 vs HiFiMAN HM-901 vs Monster Audio MA9
    Written by 00lunar
    Published Jan 19, 2014
    Pros - Various, please read below
    Cons - Various, please read below
    Hi, My name is Dawid and I'm an audio junkie. I'd like to share about Astell&Kern AK120, HiFiMAN HM-901 and Monster Audio MA9.
    Just for sake of the facts: I'm a audio journalist by profession, I work for polish press. Usually I stick to polish sites and paper magazines. But Head-fi.org is one of those portals I visit every day, constantly for couple years now. So far I've been stalker here, and figured it's time to finally write something, share a thought or two with this community. I've read lots of great reviews here, which were inspiration for me. Currawong, project86, ClieOS and some other folks are my personal heroes. Well, I believe that mainly thanks to Head-fi.org I'm doing audio journalism for a living. So there you have it, blame is on you guys, sorry [​IMG]
    Anyway, my starting point was portable audio, I remember the day when I bought my first serious IEM-s - Westone 3. Jumping from Creative EP-630 straight to those three BA driver devils was a significant experience in my audio adventure. Then, there came RockBoxed X5L, DIYMod along with RSA p-51, fancy cables and so on. You get the point, I knew it was a good start for me, we all begin somewhere and portable stuff is quite affordable way to go. I quickly moved from that kind of equipment towards desktop setups. HD 800 have appeared, then Audeze LCD-2, Audio-GD Phoenix, NuForce DAC-9, some S/PDIF converters, one from John Kenny, and lots of other various equipment. I hadn't got much time to enjoy those, KEF LS50 were bought shortly after completion of my headphone rig. A pair of NuForce REF 9 V3SE and Xonar Essence III were nice addition to those speakers. Then came some additional cabling, anti vibrating platform and couple other things that could improve what I already had at home and office. Well, people here aren't joking when they welcome newbie person by saying... we all know what. Yes, that part about beeing sorry for that poor mans wallet. It's the most accurate and sincere greeting I've ever read anywhere. As Tony Soprano said: "what can you do?" Yeah, sorry wallet, I'm aware you hate me.
    Slight hint here: for those of you looking for a pair of extremly good, yet fairly affordable bookshelf monitors I strongly suggest taking a good, long look on those KEF-s. Once those are in your posession, you won't look back with regret, trust me. In terms of overal SQ and build quality, that particular KEF anniversary item is ridiculously low priced. Uni-Q's in LS50 create UNBELIEVABLE space in front of you. OK, I've made my point, now getting back on track.
    I've been extremely happy with my KEF + HD 800/LCD-2 rigs for a while now and I seriously thought that my adventure with portable audio will be only occasional from now on, or even that'll go into hiatus. Truth be told, old habits die hard, full circle has been staggered. Once again my journalistic curiosity won, and as a result review samples of FiiO X3 and iBasso DX50 were sent to me. Next in line were Monster Audio MA9, HiFiMAN HM-901 and Astell&Kern AK120. It still surprises me that I am so heatedly chasing "it", not too long ago I thought that DYIMod + p-51 combo will be the only portable thing I'll ever need. Obviously I was wrong again, oh well, joys of beeing typical audio junkie. My personal tale ends here, yet it gives start to another.
    If someone got offended by my personal touches in "lovely" background story above, my apologies. I'm unknown here, so I figured it'd be nice to write few words about myself.
    Anyway, this "fairly short" review is about three DAP-s: MA9, HM-901 and AK120. I had all of them at the same time and I thought it'd be nice to share my findings and observations. Lots of words were written on this forum about each, so I don't think I'll surprise you guys with anything new and shocking. Since those are portable, during listening period I used Heir Audio 8.A CIEM-s along with Forza AudioWorks Hybrid Series wiring and HiFiMAN RE600. I could go with something more analytically sounding, mainly to match fairly dark and thick sound signature (or deadly neutral to some of you) of MA9, but it is what it is. I could have used HD 800 or something similar as well, but I believe that most of us are using DAP-s with much smaller in-ear products. And AFAIK there's been lots of informations regarding drive capabilities of those flagship players. But that isn't the case here, I'm going to focus mainly on build quality, UI aspects and sound comparison. Some opinions below are purely subjective, you'll see soon enough, you've been warned.
    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.      
    Two, scratch that, three disclaimers before we go:
    1. I hadn't payed for any of those DAP-s, they were delivered to me as a free samples, no journalistic surprises or secrets here. MA9 came straight from Monster Audio HQ, HM-901 from HiFiMAN HQ, and AK120 - from polish distributor of iriver, as policy of that korean company is a bit different when it comes down to sending samples to the press.
    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. [​IMG]
    Again, a lot of stuff has already been written about build quality of each DAP I'm discussing here. Their inputs and outputs are known, the same story is with displays, used materials, external memory usage and so on, I have nothing particulary new to add here. The same thing is with SQ. But I'd like to share my personal, somewhat subjective feelings about each of that portable beasts.
    Build Quality
    Astell&Kern AK120 is the smallest unit. It surprises me how tiny it actually is when compared to its rivals. That DAP is very well made. If I'm not mistaken, for a couple of days now we have a chance to buy titanium version. AK120 is pretty comfortable device to use, at least when compared to its competition and it's as solid in real life as it looks on the pictures. CNC machined aluminum chasis feels very luxurious, the device sits in pocket or on hand without any discomfort. I'd preffer it to be more taller and a bit narrower, but nothing dealbreaking for me here. AK120 thickness is very good, again I have nothing to complain. And there's that lovely volume knob, excellent job here, far better in comparison to AK100, which I also had for a short period. I've found that element in AK100 to be too loose. It's not that it has problems with volume adjustments, because from what I witnessed it doesn't. But I constantly had this feeling that one day it will just fall off, no matter how solid it actually is. AK120 doesn't have that problem in my book, it's more stable, and thanks to two aluminum and curvy convexities nearby it's more robust and better looking IMO. AK120 screen is OK, but that's it. We all know that devices like this DAP are SQ oriented, but it still is a bit of a problem for me after using one of popular and fairly new smartphones and jumping onto you know what. There, I've said it out loud.
    MA9 is different beast. It's huge. No, it's not huge, it's HUGE, that's more like it. This DAP is built like a tank. If I'll ever encounter some shady type in dark alley with serious need of robbery and I'll have MA9 in my pocket, it will be most definitly used to defend myself, it's no joke. And when the guy is down on the ground, he'll have his face burned. Aye, MA9 is extremly hot, at least sample I received. Its CNC machined aluminum body acts like a radiator, so no surprises here, and most of weigh of that DAP is its batteries, those are the main source of its temperature. During summer I could really feel MA9 in my pocket. Though this device has no problems in beeing constantly hot, it won't burn your trousers, which is a good thing, and it's stable when RockBoxed. But the fact is stil a fact: it's the hottest one I've used thus far and nothing can change this. MA9 not only looks like a brick, but acts like one on hand. I wish it could be more round here and there. Chasis of this device isn't too thick, I took a peek inside, there's a generous amount of electronics inside, mainly two huge batteries, therefore not much can be done here. But I have fairly small hands and outdoor usage was a bit problematic for me. To be honest, there's a huge gap in that regard between MA9 and AK120, the second one is a winner all the way. Though I love the robustness of Monster Audio flagship, its buttons are excellent, again good word to describe them is "robust", and overall quality of this DAP is top notch. Its fairly small display isn't something I'm not used to, in my eyes they all are alike. But I'd be extremly happy to see something better in the future. I'd say that MA9 in terms of build quality and looks has a character, it's not for everyone.
    Last one, HM-901, is a bit smaller and lighter than MA9, and obviously still bigger than AK120. HiFiMAN's flagship is in my book on the last place among all three DAP-s when it comes down purely to quality of used materials, attachment to details and so on. I've tested lots of HiFiMAN products, and I know most of them sounds really good, but build quality and looks, well, you know where I'm getting with this: competition does this stuff better. HM-901 is also robust device, and I witnessed its shockproof abilities couple times, it fell on the ground more than twice, yet it always remained unscrateched and in 100% operational. But on hand, well... plastic, no matter the quality of it, isn't something as good as aluminum or other fancy stuff. It's safe to say that HM-901 is very expensive DAP and I really would like to see some improvements in terms of looks (a bit more minimalistic chasis wouldn't hurt) and used materials. Nothing dealbreaking but you get the point. Its screen does the job poorly in sunlight and, correct me if I'm wrong, nothing can be done about that, at least for now, as brightness level implemented in its OS is very limited. Truth be told, I got used to that disadvantage, but any improvement on that field will get a big hug from me. Navigation wheel has its issues as well, it's not as fluent as it was in the beginning of my daily usage of HM-901, which is a bit odd as I thought it'll get better over time, more loose and in conclusion easier to operate. I hope you'll understand me now, but rubbing level of the wheel isn't equal, there are some spots where its resistance is more sensible than in others. Same story is with silver volume knob of that DAP. There'a also additional "issue" with that part as well, it's recessed. I get the point behind it beeing not so easily available, sudden increase of volume is impossible, we all know that, and that's what Fang Bian wanted to achieve, it's for our protection. But from my point of view I can't increase or decrease volume level using only one hand and that's something I'd like to do quite often, HM-901 competitors allow that with ease. OK, if I try hard enough it's doable, but far from comfortable, you get the point. One thing needs to be mentioned here as well: channels matching is excellent, I have to give it to HM-901. Though steppes are audible (this occurred with all three amplifier cards I have), I'd like to see something between fourth and fifth as those are volume levels I usualy use. Once again, things I've mentioned could use some improvements in the future, but I don't consider them as a dealbreakers or major flaws, I can easily live with them. HM-901 is, at least for me, better device than MA9 in terms of outdoor usage, mainly thanks to being a bit thinner and more round with unregular shapes here and there, it sits in my hand more comfortable. And it's not nearly as hot as Monster Audio flagship. I'd say HM-901 is pretty cool, even with balanced amplifier card onboard and that's a big plus for me.
    Bottom line - Buid Quality:
    In terms of daily usage AK120 does really nice job, competitors are way, way back. That device can be easily operated by only one hand, it's small and very well made. So AK120 is my number one here, HM-901 is the second, and not too far behind - MA9. Looks are very subjective, I don't want to even go there. But if someone would be burning my face with hot iron and demanding my confession in this regard, I'd say that AK120 has gold again, MA9 is not too far away, and HM-901 gets last place.
    User Interface
    To make it simple: all three devices fall short when compared to RockBoxed DYIMod. I'm a die hard fan of that soft, I can't help it. It's perfect for me, it has everything I need. That's why jumping from RockBox to anything else is usually a pain for me, when that happens I feel like a small kid left alone deep in dark and scary woods. That's true, I'm afraid of anything else. To be honest, if DAP can't be RockBoxed, it has to be really good at everything else if it'd like to be my primary source on the go. Of course sound quality is my main point of interest when we're talking about flagships, but second is software, build quality comes as third. Buggy OS is a potential dealbreaker for me. OK, now that we got that sorted, tasty bits ahead. I won't go into three separate paragraphs for each device mentioned in this review, not too much to say here. AK120 holds its ground fairly firmly. Touchscreen is a matter of taste, though. IMO it became way too popular thanks to smartphones era, but I don't need it as a portable audio enthusiast. I'd go for physical buttons anyway, those are more reliable for me, and DX50 or Astell&Kern OS is not nearly as good as the one in SGS III or iPhone, that's a fact, it's hard to argue with that. I hadn't got a chance to fiddle with DX100, but I'm guessing it represents somewhat similar level to two DAP-s mentioned above in terms of screen responsivness and such, therefore still nothing groundbreaking for me. Again, jumping from iPhone to DX50 and other touchscreen based DAP-s is quite painful experience for me and I know that some of you will sympathize here as well. Anyway, AK120 has its issues, my main point is that its navigation isn't as fluent as I'd like it to be, i.e. browsing files list is laggy. I'm not sure if this can be fixed in the future OS updates, I'm guessing that guys from iRiver are limited by AK120 internals in that regard. From my point of view overall usage of that DAP is quite good, but I see room for improvements. We all saw FiiO X5 OS smoothness recently, that's something I'd like to see in touchscreen based portable players as well, for future flagships it's a must in my book, we all get used to good stuff quite easily, don't we? HM-901 could use LOTS of improvements as well i.e. I miss clickwheel sound from my DYIMod, I always had it on, subtle and quiet, but it was constantly on. But that's a small issue. The bigger one is overall slowness, responsiveness of physical buttons and inability to adjust wheel speed. I'm aware that guys from HiFiMAN want to create their products from A to Z in their labs, but my guess is that 99% of us would be in 7th heaven if we could exchange current HM-901 OS to RockBox, I really hope it will happen one day. I don't want to be monothematic, but yes, in my case it's about RockBox again. And that's what guys from Monster Audio did. Standard OS on their devices is, to put it as simple as I can, unusable for me. The one put onto HM-901 is at least stable, I can't say that about MA9. Often crashes, not reliable battery lifetime indicator and so on are major disfunctions for me. But that aside, MA9 has RockBox, which works as it should. And that's the solution to all my problems, this is enviroment well known to me, which I like, couldn't be better, I couldn't be happier. It's very fast, MA9 turns on in couple seconds. No matter how fast I'm going with buttons of that DAP... there's no lag. Nothing much to add here.  
    Bottom Line - User Interface:
    MA9 has it. When RockBoxed, it's a great DAP, unique on many levels. Competition is, at least in my eyes, far behind. AK120 is second, because even though I see screen tearing while browsing files list fast, touchscreen is responsive on acceptable level. And HM-901 is last one. But IF MA9 couldn't have been RockBoxed, it would be on last place.
    Sound Quality
    And we're getting to the end and most tasty parts. Again, lots of words were written about AK120 and HM-901, a bit less about MA9. On this forum I see, that people favor HiFiMAN's SQ more than AK120, other things aside. And to make it short and simple I agree, HM-901 sonds better for me too. MA9 is different beast, but we'll get to that in a moment. For those of you, who do not like to read much this will do:
    HM-901 is king of dynamics, yet it has very refined sound signature, AK120 sounds smoother and more polite overall when compared to HiFiMAN's flagship, and MA9 is the most laid back and dark of all three. There. Folks starving for details should read on. But bear in mind that I won't go deeply into each players sound signature, I believe all of you here already know which one plays in what  way. I'll focus on the differences between them and, in the end, how they affect me. Onwards we go then.
    HM-901 is the most dynamic one out there, this player literally makes my blood boil. It also is the most forward sounding DAP, with the best lows overall. Those are very, very punchy and, to my ears, they have a slight midbass hump when compared to other devices. I usually don't like it to be boosted in any way, as I'm very "boominess sensitive" person, but with HM-901 nothing bad is happening in that department, quite the opposite in fact. Bass of that DAP has also a bit more stiff texturing, or not as round as competition, in that regard it is on one side of the spectrum, MA9 is on the other (with the least amount of it as well), and AK120 sits somewhere in the middle. But again, HM-901-s bass has the best dynamics and goes lowest. As for midrange, I've found HM-901 and AK120 to be somewhat similar here in terms of temperature, the second has mids maybe a tad warmer. MA9 has them the most neutral, those might be seen as a bit dark. But all three products are very good here; natural, dynamic and detailed, I have only good things to write here. For some time I thought that HiFiMAN's DAP has mids a bit more forward and direct sounding when compared to other devices, and to some degree I see them that way. But it came to me that it's all about their soundstage placement, we'll get to that in a second. HM-901 has similar amount of highs as AK120 and sounds a bit brighter here, MA9 is behind in that regard when compared to competitors, we all know why. For those of you who do not, here's short explanation: MA9 DAC, PCM1704, tends to have them a bit rolled-off. For some people that kind of presentation is seen as the most accurate one, to others - as a roll-off and I'll leave you with that. I can only say that my ears are telling me that MA9 sounds excellent in that regard, no matther what. Now onto the soundstage stuff, things are getting a bit hairy here. Overall, AK120 is excellent in that regard, such tiny DAP, so amazing spaciousness, kudos. HM-901 is a bit smaller on that field, I have depth on my mind here, mids are more closer to listener and that's why this device sounds more direct to me. Those aren't huge differences, yet noticeable, at least that's what my ears were telling me during my listening period. AK120 soundstage is very wide and deep, lots of layers there. HM-901 also is extremly good on that field, but since midrange is more closer to the listener, well, you get the point. As for MA9, the amout of air in soundstage of this DAP is enormous, overall imaging and depth is top notch, but that's not all. I don't know if I can describe it properly, but the way musicians are placed one next to another, the richness of the whole show... magic. Soundstage of MA9 has even more layering than AK120, at least that's the way I see it. Monster Audio flagship delivers such scenical realism, that I see no competiton on the market for that device in this regard, and I've heard a lot of DAP-s. Of course there might be an amp which would do better with AK120 or HM-901, but when we're talking about playing straight from headphone-out... nope, at least not to me.
    Bottom line - Sound Quality:
    It's just a "shortcut" of what's above, conclusion and my pick of the day is below. All three DAP-s do sound excellent, I have no doubt about it... of course price, build and UI quality aside. MA9 offers very musical and addictive sound, there's ton of smoothness there, and cherry on top would be excellent soundstage and imaging, those are the strongest points of that device in my book. It has the lightest, roundest and the most polite (still, with right IEM-s punchy as well) bass, but even though it's very, very good. MA9 highs may seem rolled-off but once you get used to them, they do sound very enjoyable. And overall presentation of this DAP some of you will consider as dead neutral, and another - a bit dark. If that kind of sound is your cup of tea, drink and enjoy, you'll thank me later. AK120 sounds very natural as well, though brighter than MA9. In comparison this device has a bit less rounded, yet punchier bass and very impressive soundstage, the biggest one out there, I'm utterly and constantly impressed by it. In terms of sound quality AK120 is a kind of safe choice, that's the way I see this DAP. HM-901 is one dynamical beast, the amount of energy this thing puts into music is beyond any other portable device I've heard thus far. But Fang's most expensive portable product isn't all about brute force. Yes, that's one of key features, but it also sounds very, very musical, its the brightest sounding device of all three, but not too bright, don't get me wrong. Thanks to that kind of presentation the amount of details HM-901 provides is very generous and this rocks my boat. And bass, I have to write it again, the best and lowest one I've heard thus far in DAP, for some time now it's a reference grade for me. And the soundstage, even though a bit more closer than the one competitors deliver, is also impressive. That's it. Let's get down to conclusion.
    Final words
    The time has come to sum things up. I may repeat myself couple times now, but I'm sure those of you who read only endings will be delighted. To be honest, there's no perfect DAP, even when it comes down to spending 1000$ or more, it's a kind of obvious thing to write. Yes, unfortunately we have to go to compromises and not much can be done about it. To some degree we can rely on firmware upgrades but that's about it. When choosing between MA9, HM-901 or AK120 we have to prioritize our needs. Those of you who have read what I wrote above will know what I'm about to do here. In terms of pure OS, MA9 is a way to go, this device has RockBox. AK120 with somewhat lagging, but fairly usable interface comes as a second, and in the end there's HM-901, which in that regard is slow and very limited in terms of available options. Physical buttons/touchscreen wise, MA9 is OK, AK120 isn't as responsive as I'd like it to be, but still usable, HM-901 is on the last place. In case of this particular DAP there's plenty of room for improvements, both in terms of build quality and OS, I'm sure HM-901 owners can confirm.
    AK120 does the outdoor usability job way better than competitors, obviously due to its smaller size. HM-901, even despite being huge thing to carry aroud is still more usable on hand than brick alike MA9. If I had to choose one DAP mainly based on stuff mentioned above without SQ factor, I'd go with AK120, MA9 as my backup plan (RockBox FTW), HM-901 would be considered as a third option. But I'm sticking to the last one all the time, even despite of its UI/build quality issues I shared in this review. Yes, it's all about sound of HM-901. I can't help it, Fang did it oh so right.
    In terms of pure sound quality, the way I see AK120 is that it's a great DAP and a safe choice to make. People who got AK120 are mostly happy, no doubt here, no matter if we're talking about casual users or audio junkies. Some of them won't even look back, beeing in seventh heaven thanks to sound quality that small DAP provides. But not me, I see AK120 as jack of all trades and master of none, with one exception: enormously big soundstage. Sure, it could only be me, as I got used a bit too much to my HD 800 and LCD-2, as those are on the opposite sides of the spectrum, very different sound signatures they provide. Hence maybe I'm all about opposites and nothing in the middle can break this wall, I'll leave you guys to decide whether because of that my judgment calls are biased. But to my ears HM-901 sits on one pole, MA9 has its comfy igloo on another and AK120 is placed somewhere in between those two. Again, to my ears it's not even about tonal balance, but the fact that HM-901 and MA9 simply give me more listening pleasure than AK120, on many levels. But lots of people are all about the middle, Astell&Kern flagship model will be their choice number one and I see nothing wrong with that as well.
    As for sound quality of MA9 it goes like this: when I'm in right mood, sitting in the right chair, drinking right beer, contemplating about meaning of life in the right way and unexpecting spanish inquisition, well, I can literally drown and melt in that laid back sound, it gives me oh so much joy. Even with thicker sounding IEM-s, even despite those shouldn't get along with MA9. Yet they do, at least for me and it seems that when that happens - time stops, there's only me, music and this defense capable, aluminum brick sitting in my hand. Got carried away, sorry. But as I wrote, listening to MA9 is a kind of ceremony for me, right time and place are needed, nothing casual about it, no matter how funny or poetic this may sound. That's why this DAP is so special to me. And there's HM-901. Again, another metaphor is needed, but not so poetic this time. This device is like a vintage car to me. It may look arguably and have no luxury onboard, to a degree that even windows are handled by rusty, old and creaking winches. But who cares, this thing has 1000+ ponies under the hood. Therefore it's dynamic and fast as hell, I'm talking about a beast here, not a car. Aye, it can easily make me crash on the very first turn. But if I'm up for it, well, competition will be left far behind. And that's what HM-901 is all about, I'm all in, I can handle and appreciate it in 100%, I have proper tools and set of skills. When paired with my Heir Audio 8.A and hybrid IEM cable from Forza AudioWorks, well, it delivers the best sound on the go I've ever heard, period. That's why I'm constantly using HM-901, even despite its flaws and the fact that I really am spoiled by devices way more comfortable in use. Awkward, yes? But in this case sound quality is above anything else, I'm amazed, HiFiMAN flagship DAP is end-game device for me. At least until something better sounding shows up. Besides, it's hard not to like vintage cars, ain't it?
    Had fun writing this and I'm glad I finally did. I hope to do this again soon. Sorry for any typos I've made. If something is unclear on any level - feel free to ask. And, of course, big thanks to my suppliers. Cheers.

    P.S. If anyone is interested, below there are some product photos I did. They were published somewhere else, but I'm the owner of those.

    1. View previous replies...
    2. passionforroxk
      Hi, do you think hm901 can drive or will make a reasonable sound with hd800? I'm considering pair hm901 with balanced amp card with either hd800 or th900? Any thought?
      passionforroxk, Mar 11, 2014
    3. awry
      HD800 no. Th900 just fine even with the iem card. 
      awry, Mar 13, 2014
    4. gapianca
      HIFIMAN HM-901
      An object that should cost $ 300.00
      The sound is good, but not in keeping to product price.
      construction and qulity of materials ... really bad.
      The battery has a very limited duration.
      The HM-901 has a very limited versatility.
      The HM-901 is a very bad product.
      the assistance of the parent company is unseemly.
      Hifiman HM-901 was a big disappointment
      gapianca, Apr 22, 2016
  4. fengwei007
    This is the best sounding portable DAP I've ever heard, sound better than AK120 which I sold. Very flexible w/ the option of different amp cards.
    Written by fengwei007
    Published Oct 14, 2013
    Pros - Excellent sound quality, flexible w/ different amp cards
    Cons - UI a bit awkward, battery life a bit too short especially with balanced amp card, a bit warm after playing for half an hour and longer
    Can't believe there is no review for this excellent DAP yet.
    I won't duplicate what I said here: 
    No regret after I bought it the second time, and this time I'm gonna hold it until a better Hifiman DAP comes out. Would have given it a full 5 stars if not due to its UI. 
      VladGuardian likes this.


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