The Calyx M is a solid entry into the high-end DAP market for people looking for a good, all-round unit.

A Review On: Calyx Audio M

Calyx Audio M

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Review Details:
Audio Quality
Battery Life
User Interface
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Pros: Easy to use and attractive user interface. Great sound quality, close to AK240. Full-size SD cards can be used.

Cons: Quite large. Poor battery life. User interface is a bit slow and doesn't cache album art. DAC performance isn't as good. No folder browsing.


Thanks to Calyx for allowing Team Tokyo to borrow a unit for review.


Note: Version 0.6 and 0.95 of the software were originally used for this review. I've updated it to reflect performance with firmware 1.01.

The first thing many people wanted when they heard about the Calyx M was an AK240-level device without the price tag. Good luck! But in all honesty, if there is another company (other than Sony) that might be capable of invading the market with something competent, it would be another Korean company. Having owned a Calyx DAC in the past, the DAC 24/192, I was curious to find out how their portable would fare, so when the CEO of Calyx introduced himself at the May 2014 headphone festival in Tokyo, I didn’t hesitate to ask for a loaner unit.

The first physical impressions I had of the unit is that it is big, relative to the other DACs I have on hand. If you saw the photos of each individually it is natural to assume that the AK240 is the largest, when it is actually the smallest overall, if a bit thicker than the M.  Other than the very straight-forward design of the M compared to the X5 and AK240, the two most noticeable physical details that set themselves apart from the competition become quickly apparent on picking it up: The two memory card slots: one microSD and one SD, and the magnetic volume control. If you’re wondering whether you can take the volume control off, the answer is: Yes, you can. But the magnets are strong enough that if nobody had told you about the volume control being magnetic you probably wouldn’t notice, as it is almost as difficult to remove as a non-screw-tightened volume knob would be.

The large screen is filled with an equally large, easy to read and beautiful Android-based custom user interface, which one navigates primarily by swiping left or write to get to the music and Jukebox feature respectively. Menus at the top access information and settings for one, and the currently selected album or playlist on the other. Centrally, of course, is a playback screen with the play/pause control overlaying the album art and quick access to repeat and shuffle available, along with track information.  This makes the Calyx M’s user interface very quick to pick up and use.

The lock screen, which uses album art as the control to unlock it can be disabled in the settings, allowing the power button to switch on the screen and take one straight to the music playback controls.

At present the user interface stutters a little when swiping quickly, and quite severely lags during music playback if you try and swipe quickly. Card scanning can take a few minutes if you have a lot of music, but Calyx have been working steadily on not only improving the performance but adding features such as search. Features such as easy re-ordering of songs and the Jukebox feature are good with most controls large and easy to tap. However, the lack of folder browsing ability may be a show-stopper for some.  Indeed it was a problem for me, as I have a separate folder of DSD files that I usually access but can't easily on the M.

Tapping and holding on a track, for example, brings up the options to get info, add it to the Jukebox or to a playlist or delete, for example, which is very handy. Likewise, Jukebox songs can be selected individually or in groups and new playlists created.  Shifting off the necessity of creating playlists on my computer is definitely a bonus for me.


For different types of headphones, 3 different "Impedance Matching" settings, labelled "Low", "Mid" and "High" are included which change the volume profile. This has confused some people into thinking that they change the output impedance of the player and will sound different when all they are doing is adjusting the volume.

The main troublesome aspects of the user interface is that it badly needs an album art cache, as the album art has to be loaded from scratch every time the unit is switched on, though it doesn't take nearly as long as it did before 1.01. During very vigorous scrolling while playing back high-res music, I did manage to get the music to skip. There have also been complaints from users about battery life only lasting 4-5 hours of playback (3.5 hours with DSD and the screen off). However, Calyx are working steadily on improving the software, so I’d expect in time things to get better.

Sound-wise too, the performance is very good, if a bit behind the AK240 and seems to be a bit “darker” in presentation. Music comes through cleanly with a wide soundstage whether using IEMs or full-sized headphones, for which the Calyx M is more than capable of driving. The Calyx M with the HD-800 and Audeze LCD-X, while not driving them with the authority of a desktop amp still managed to do a good job with the sound, the main thing lacking was volume level on the tracks from David Chesky’s Open Your Ears album. The gain level was far better suited to IEMs. However, gain settings exist in the settings under “Impedance matching”. With version 0.95 of the software, putting the M on the highest setting improved the performance with the HD-800s compared to version 0.6.


At the request of some Head-Fiers, I compared the sound to my iPhone 5. Both with IEMs and full-sized headphones there was a distinct jump in both clarity and headphone drive with high-quality music. Compared to the AK240, the latter had the edge on detail, but to use the words of a fellow member, the Calyx sounds more "full-bodied" and was a better match with less bass-strong headphones. The M was a touch less smooth in the treble compared to the AK240 -- only in comparison however. I'm not sure if this might disappear with use as I've experience with other equipment that was new when I first received it. Using the single-ended output on the AK240 and firmware 1.01 on the Calyx it was very hard to make out any difference. 


The biggest difference was going from the X5 to the Calyx with full-sized headphones. The X5 is very poor with high-impedance headphones at producing a wide stereo image, being far better suited to IEM usage. Going from there to other DAPs I feel the differences come down more to sonic preferences and features desired, as the Calyx doesn't have optical output, a dock, wireless update and streaming for example, nor as much internal storage as the AK240. Going a bit sideways in comparisons, the M sounds a bit more spacious, though not as "meaty" as the Aurender Flow. That makes me prefer the M, though at least one person I know feels the other way around.

The Calyx M can also be used as a DAC, though I did find the sound quality to be somewhat flatter-sounding and dull compared to using it as a DAP, with better USB cables and high quality external USB power improving things. Since USB isolators are quite inexpensive nowadays (eg: The Schiit Wyrd) the Calyx M can be readily used as a high-quality DAC or pseudo desktop solution.

Overall the main thing is that the Calyx M will be giving the iBasso DX100, AK100II and AK120II a good run for their money, if not quite, in my opinion, the AK240 (at least not on features). I do think in a year, if they keep up the steady improvements to the software, they’ll gain a lot of fans.


That battery life is a bit hard to swallow, and it sounds like there's quite a few kinks to work out before it becomes something I'd consider (no folder browsing's a bit of a deal breaker).

Thanks for the insightful review!
The only thing that drives me crazy is absence of folder browsing. If they fix all the bugs in firmware 1.0, It will be nearly as good as AK240. It can already beat AK240 in storage capacity. You can put a micro sd to SD adapter and insert two 256GB SD cards. Nonetheless, its huge capacity is not fully usable without a proper folder browser. 
It's shocking how something so thick can have such anaemic battery life. Hopefully Calyx can improve that via software optimizations, though I suppose doubling it would be out of the question.
Thank you for the review!
That interface lag seems embarrassing, especially at that price point. I can see stutter in nearly every transition animation and the vertical scrolling seemed to be dipping below 10fps. Even if this was the best sounding DAP on the planet, I personally could not deal with the lag seen in this video. To be fair, I'm extremely OCD about smooth transition animations and vertical scrolling. I suppose it should be fine for most people.
lawl @kurochin I'm still using my hm801, I think battery is down to like 3.5 hours xD but ofc that DAP is a dinosaur now
still the "full bodied" sound of the Calayx M might win me over... it got a Line out 
I think they custom-made their own interface, which is why the initial issues. For a company, spending many months perfecting it while holding off release they lose a lot of money, so at some point they have to decide it is usable enough and release the device. I gather they are selling like hotcakes in Korea though.
Because the DAC seems to be lacking that's where Light Harmonic Geek Wave or Geek Pulse would take over. Great device just needs a little help with other features.
Informative walk through of the player.  Interesting that Calyx is also iRiver?  
@SilverEars Not sure if you saw the clarification: I said in the video "Same country". They aren't the same company. :)
Curra, does Calyx M sound better than Oppo's HA-1???
I'd like to hear your opinion.
@kawaivpc1 I didn't compare them, so I couldn't tell you. The problem is, also, they are radically different components, so I'd consider purchasing one or the other for completely different reasons.
I know they're made for different reasons, yet they're in the same price range. If you could choose one of them for sound quality, which one would you choose? 
@kawaivpc1 Seriously, I wouldn't, because it depends on with what headphones or IEMs you intend to use them with, or whether you'd use either as a DAC, a DAC/amp, a DAP only and a whole bunch of other factors. So unless I was to do a proper comparison in that way, I don't think it is sensible to answer such an overly general question such as that.
With firmware 0.96 which came on my unit there is folder browsing if you want it.
I've updated the review with the changes in 1.01.
Currawong, Do you recommend it with headphones like Final Audio Design and B&O H6 or B&W P7?   I have the iPhone6.
@T65design I don't have any experience with those headphones, sorry.