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New Head-Fier
Review Questyle M12: More than a top performer
Pros: Totally uncolored, natural, organic, relaxing, transparent and full of details sound; great soundstage, top separation and holographic image; amazing dynamics; outstanding quality equaled to desktop products.
Cons: Maybe not the tallest and deepest soundstage, but I am nitpicking.

I think that Questyle is one of these companies that has caused a sensation in the Hi-Fi world and for a good reason. The company was founded on December 12, 2012, and a year and a half later applied for a global PCT patent on “Current Mode Amplification (CMA)”, a new technology that essentially revolutionized how an amplifier works (more on that below), and since then it has been used in all Questyle products, desktop or mobile.

Questyle products are designed to give the consumer the highest, yet trouble-free, audio quality, and they are manufactured at the Foxconn Technology Group, which is known to be one of the technological giants and highest quality manufacturers in China. Look at any of these products and you will immediately realize that it “talks quality in and out”. During development, Questyle uses Audio Precision (AP) to test and analyze sound, spending weeks on sound listening, again and again, and even inviting some audiophiles to join the listening in order to perfect both the specifications and the design details and through that sound. And after manufacture, every Questyle product undergoes a strict sound and quality control.

It is then no wonder that since 2015 Questyle has obtained 20 international awards, such as the CES Innovation Award, the iF Industrial Design Award and the VGP Lifestyle Award. Questyle products are sold in the USA, Japan, Germany andthe UK among many other countries, while Questyle Audio has been honored as one of the top 50 competitive enterprises in Shenzhen by Hurun Research Institute in 2017.

So, it did not go unnoticed when, last year, Questyle presented M12, the first mobile headphone Hi-Fi amplifier with DAC incorporating the same technologies as the company’s desktop products, which is the product we are going to review today.



M12 uses one of the ESS flagship DAC chips, the ES9281AC, which has decoding capability up to PCM 384kHz/32bit and DSD256, while it renders Master Quality Authenticated (MQA) technology.

Even more impressive is a number of technological innovations that M12 incorporates:
  • The first and foremost innovation is undoubtedly the patented “Current Mode Amplification (CMA)” technology. This goes back to 2006, when Mr. Jason Wong, Founder and CEO of Questyle, being in his University Lab, came across the concept of “current amplification”, which up to then was only used in video processing and high-speed communication. It was a very fascinating idea, as it is both high-speed and very dynamic in nature. So, Mr. Wong asked himself: What if current amplification is brought up to audio? The idea here is, by means of transistors and a fully discrete structure, to amplify current, instead of voltage, in a pure Class A state. The result is multiple: Complete elimination of the Transient Intermodulation Distortion (TIMD); ultra-wide bandwidth (> 500kHz) and ultra-low distortion (THD+N lower than 0.0002%, that is, 10-100 times lower than ordinary professional devices,challenging the physical limits of audio testing). Even more, the CMA technology can be used for amplifiers of any power level (10mW-2000W) and of any size (thousands of square centimeters for some professional amplifiers). It was because of this last ability that the CMA technology could be brought up into a small form such as the M12 unit.
  • The second technological innovation is the Torex high-efficiency power management, which ensures low power consumption without overheating, thus longer battery life and longer playback (5-6 hours).
M12 layout.png

Based on all the above, M12 comes with really impressive specs: Frequency response 20Hz-20kHz/±0.1dB; THD+N 0.0003%; background noise lower than -130dB; self-adjusting to suite headphones of impedance 8Ω-600Ω; and power 12.26mW at 300Ω. If the detected impedance is less than 70Ω, M12 will self-adjust to low gain output; if it is more than 70Ω, M12 will self-adjust to high gain output; and if it is more than 600Ω, M12 will automatically switch to 2Vrms line out.

M12 graphs.png

The housing of M12 is made of metal (I suspect CNC aluminum) and comes in two colors, black and silver. The quality is absolutely superb, and apparently Questyle in creating M12 miniaturized one of its bigger headphone amplifiers/DACs.

M12 colors.png

On the front plate there are two lights: A gain indicator for low gain (green) and high gain (red) mode; and a data indicator for PCM (green), DSD (red) and MQA (magenta).

M12front plate.png

On the other hand, M12 is petite, its dimensions being 51mm x 16.5mm x 8.1mm. It is truly unbelievable that Questyle put so much technology in such a small device. Of course, all these goodies should translate into sound quality, so let’s find out.


Before I describe the performance of M12, I should mention that all testing was done after I upgraded the firmware (FW) to the latest one 9277; please see

Now, I am using the word “performance”, because M12 has an amplifier and a DAC section, so I shall comment on each one of the two, and the combined effect is what I call performance.

The main characteristic of M12’s sound is its amazing tonal balance; balanced sound does not mean what some people view as or call neutral sound. One has to be very careful with this term and because of that I very rarely use it. I do not believe that there actually exist neutral sounding products. Truly neutral means no engagement and no musicality whatsoever, so maybe good for studio recording but not for listening to music. M12’s timbre is completely uncolored, and at the same time organic and natural.

The bass is tight, with the right amount of sub- and mainly mid-bass, so you will never feel that M12’s sound is warm and certainly not cold; it is quite interesting that Questyle people succeeded in making M12’s sound organic but not warm, which I have to admit it requires particular tuning skills.

The mids are very natural and relaxing, and both female and male vocals are very nicely presented; never forward or “shouty” and never recessed. I should also note that although the mids are very natural, they never tend to be intimate.

The tremble is extended but never hissing or harsh; so, one gets plenty of details, sometimes even the finest nuances of music, without ever getting tired even after many hours of listening.

The soundstage is great in width, and I was to nitpick an M12 drawback this will be that its soundstage is not that tall and deep. The separation is absolutely great and the image is totally holographic with the musicians and the singer always in the right place.

The dynamics is truly amazing, and M12 is another beast that can drive any IEM or headphone up to 600 Ω where it automatically switches to 2Vrms line out; it appears that the unit has ample power without ever changing its sound signature. Furthermore, M12 is extremely quiet, without any floor noise even with the most sensitive IEMs. Of course, all this is the result of the Current Mode Amplification technology, this unique feature that characterizes all Questyle products, and it is added for the first time to a mobile unit.

Overall, the timbre is totally uncolored, natural, organic, full bodied and transparent, without being euphonic. The resolution is exemplary, with plenty of details, the soundstage is great in width, the separation and image are absolutely top, and the sound is extremely clean. The job Questyle people did in tuning was unbelievable, and to this certainly helps the ultra-low distortion of M12.

The testing of M12 was done with a variety of musical pieces from TIDAL, varying among the classical songs “The Look of Love” by Diana Krall, “Fast Car” by Tracy Chapman, “Over My Head” by Asaf Avidan and “You Don’t Have to Say You Love Me” by Jack Savoretti to mention just a few; Jazz pieces, like “Samba De Orpheus” by Vince Guaraldi; and symphonic pieces like “Fanfare for the Volunteer” by Mark O’Connor. I also used a variety of IEMs and headphones, among them Final A8000 and Pandora Hope VI. In all of them, M12’s performance was completely uncolored, natural, organic, relaxing and transparent, nothing short of outstanding.

I compared M12 to my reference portable DAC/AMP, the Resonessence Labs HERUS+ (an upgrade of the original HERUS that has now discontinued). The HERUS+ uses the ESS Sabre ES9010K2M DAC chip, it has a 1/4 inch output and its MSRP used to be $395.00. On the other hand, the design and implementation of the HERUS+ was done by the people who designed and implemented the ESS chips (Mark Mallinson, the owner of Resonessence Labs, was formerly Director of Operations in ESS), so they took full advantage of the ES9010K2M’s capabilities. The result is a portable DAC/AMP that is made like a tank, it is a pleasure to look at and a bigger pleasure to listen to; its performance is truly stellar. Well, M12 is damn close to HERUS+; the latter is a bit more full bodied and a bit more detailed, but just a bit. I scratched my head why I like so much M12 and now I know: Because its performance is so damn close to that of HERUS+! Can you buy HERUS+ today, and even if you could, would you spend $395.00 on it? The answer is no, but now you know that you have an option: It is called M12!


It is not enough to say that M12 is an amazing unit. You get a petite amplifier with DAC equipped with the Current Mode Amplification module, a truly revolutionary technology used for the first time in a mobile unit. As a result of this and its flagship ES9281AC DAC chip, the sound is totally uncolored, natural, organic, relaxing, transparent, full of details, with great soundstage, top separation and image, and amazing dynamics. On top of all this, M12’s quality is outstanding, the same as in Questyle’s desktop amplifiers.

M12 is probably the best implementation of a a portable amplifier with an ESS chip, and one of the top three DAC/AMPs in the market today. At $139.00 it is a bargain. More than a five star performer!

Reviewer’s note: The reviewer is grateful to Jamie Zhou of Questyle Audio for sending him a sample of M12.
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How would you compare to M15 ?

I am working on my review on M15. The latter is the best implementation of an ESS Sabre chip on a mobile DAC, and one of the two or three best DAC/AMPs nowadays.

In the SE 3.5mm output, M12 and M15 are, soundwise, pretty close. However, in the balance 4.4mm output, M15 is benefited from the extra amplification and this shows on its sound performance.

All in all, M12 is a top performer, but M15 worths the extra money.


100+ Head-Fier
Questyle M12: King of $150 price bracket
Pros: + Superb build quality with machined aluminum
+ Smaller size ensures portability
+ Smart Impedance works just great
+ Good amount of power is enough to drive most IEMs
+ Reference grade tuning
+ Good resolution and staging performances
Cons: - missing balanced output of 4.4mm
- no lightning port adapter out of the box
Questyle M12: King of $150 price bracket


Summary & Objective:

The @Questyle M12 is the first ever dongle release by Questyle promising outstanding performance as always. It comes with great build quality and some nifty features like Smart Impedance detection and Current Amplification which makes it a great contender for the price bracket.



The Questyle M12 comes with great machined aluminum build and promises outstanding sound performance for the price bracket. It is the first ever dongle release by Questyle and have some very nifty new features built-into it.
The Questyle M12 is priced at $139.


This unit was sent by @Questyle for the purpose of an honest review.
Everything mentioned in this review are purely my own based on my experiences with the Dongle DAC/AMP.

Design, Build & Features:

I wouldn't want to make this a very long review by describing each feature but for people who want to know here are some extracts from the Questyle website.




The Questyle M12 comes with $139 price tag and the specifications are as below:

Material: CNC machined aluminum
Color: Black / Silver
Size: 51[L] X 16.5[W] X 8.1[D] (mm)
Operating System Required:
Android phone and pad: Android 5.0 and above
PC: Win10 1803 and above
Apple cellphone: iOS (You need to buy an OTG cable for Lightning to Type-C.)
Apple computer: Mac OS
DAC Capability of M12:
PCM: 32kHz – 384kHz (16/24/32Bit)
DSD: DSD64(1Bit 2.8MHz) , DSD128(1Bit 5.6MHz), DSD256(1Bit 11.2MHz)

Output Power:
Built-in smart detection circuit will automatically self-adjust the output power to fit different
impedance of headphones.
When the detected impedance is less than 70Ω, M12 will self-adjust to low gain output.
When it is more than 70Ω, M12 will self-adjust to high gain output.
When it is more than 600Ω, M12 will automatically switch to 2Vrms line out.
Frequency Response: ±0.1dB(20Hz-20kHz)
THD+N: 0.0003%
DAC: ESS flagship USB DAC chip ES9281AC





Items Used for this Review:
@Vision Ears EXT, @DUNU-Topsound ZEN PRO, @CampfireAudio Dorado 2020, Holocene, Honeydew, @UniqueMelody MEST MKII, @IkkoAudio OH2, Tinhifi T3 plus, P2 Plus

Source : iPad Pro, iPhone 13 Pro max
Streaming Source: QOBUZ


Tracks Used:
The tracks I have used can be found from the below playlist that I have used and generally use for most reviews...


QUESTYLE M12 Sound Impressions in Short:


The Bass sounds just great. has enough details and is able to produce enough attack in the mid base region as well. In tracks like : "Anna R. Chie (Remastered) - Konstantin Wecker" and "Dreams (2001 Remaster) – Fleetwood Mac" you can feel the the deep attack of the different instruments with just enough details. The thumps and slams are very enjoyable.


The Midrange really just excels in terms of every single element. It is able to produce an good creamy smooth and textured midrange that is soothing to the ears while having enough details in it. The vocals are natural and both male and female vocals come with good amount of details. Instruments sounded natural. In tracks like: "Anchor - Trace Bundy" and "Ruby Tuesday - Franco Battiato" while you will love the overall midrange specially transients of the guitars, violins etc... instruments and the vocals.


Though some people may complain the ESS DAC chip being a bit bright signature specially in the Treble region - this implementation is just great and seemed quite the reference grade. Hence, the treble just sounded nice and full and without any unwanted peaky-ness.


The staging and resolution is just great and just the amount the track requires. Nothing artificial here. Tracks like: “ She Don't Know – Melody Gardot” or “Bohemian Rhapsody (live aid) – Queen” sound good & enjoyable. Resolution is amongst the best in the price bracket and better than few others above it's price bracket also.

Impedance & Amplification:

The smart impedance features seemed to work correctly in all cases that I've tested and the dongle was able to power all IEMs with the rare exception of the Tinhifi P2 plus which requires desktop grade amplification and power.

The best pairing experiences I have found are with slightly warmer or reference grade IEMs. Unlike some other ESS DAC implementations, this doesn't have the tendency to increase peaky-ness when paired with bright IEMs


Though I have compared all 4 of the dongles I had in my possession - @iFi audio Go Blue, Qyestyle M12, Luxury precision W2 and the Cayin RU6 dongles, it wouldn't be fair to compare Questyle M12 with dongles twice it's price. Hence, comparison had been done mainly with the iFI Audio Go Blu which comes at slightly higher price range of $199. Since the Go Blu has BT features also which is not present in M12 - the below comparison is based on wired connection only.BT performance not taken into account here.


Questyle M12 vs iFi Audio Go Blu:

Build quality:
Both dongles are of extraordinary build quality and have lush premium looks.

Features & Amplification: While BT features of the Go Blu not taken into account - the smart impedance is a great nifty feature of the M12.the volume dial is a great feature of the Go Blu. both dongles have good amount of power and amplification

Sound performance: This is where the M12 was found significantly better. The midrange on the Go Blue sounded quite thin and was missing enough texture. the treble also was found a bit on the brighter side on the Go Blu. The M12 was surprisingly quieter than the Go Blu also.

Resolution & Staging: both dongles have equally good staging performance but the Go Blu lacked slightly in terms of resolution to my ears.


Conclusion :

The superb performance of the @Questyle M12 makes it an easy recommendation to anyone who is looking for a dongle in the $150-200 price range. There are many dongles below the $150 price ranges including Shanling UA2, etc.. and some at slightly higher range like the Go Blu - but the M12 outperforms them all and can easily be considered the King of $150 range dongles.
@asifur I have RU6 on the way to me, while waiting I was thinking if I should pick up M12 for comparison. Since I only use single ended so having only 3.5 mm jack for me is perfectly fine.

Though based on your comment about price, is it safe to assume I should just keep waiting for my RU6 to arrive?

Or is M12 different enough to be still worth picking up?

My preference is forward female vocal, sparkly guitar/piano/violin and rumbling bass. And generally prefer a bit aggressive sound rather than soft sound. My genre is acoustic / rock / pop, thanks!
@Hyde00 I'd prefer the RU6 over M12 any day... just love the analogue and very enjoyable tonality with powerful output. Best if you use balanced plug though.
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lol gotcha, I'll keep waiting for my RU6 then......... been 3 weeks.... so slow sighhhh (bought from member)......... ok I'll be patient. I'll pick up a balanced wire once it arrives. Thanks!!! :D
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Small size, Big sound
Pros: 1. Stellar balance across the range
2. Doesn't sound digital or processed unlike many of its competitors. Natural and analogue ish sound reproduction
3. Extremely precise. Class leading imaging and detail retrieval. Excellent Separation and layering.
4. Clean, neutral and clinical but not at the expense of musicality
5. Loads of body/meat in the sound. Really difficult to find flaws in midrange, bass and treble
6. Exemplary sibilance control. no shrillness or harshness or glassy edge around the sound
7. POWERFUL. Can run power hungry cans like HD 650 with ease. Auto gain works perfectly but has drawbacks in specific cases that I'll
highlight in the Cons section
8. Excellent heat management. Doesn't get hot at all only slightly warm
9. Zero noise. I have seen reports of issues with usb 2.0 and smartphones but havn't faced no such issue myself
10. SMOL
Cons: 1. Soundstage can feel a little cramped once you come back from relatively wide sounding sources but nothing deal breaking and barely
noticeable after a while
2. Auto gain system doesn't work properly with low impedance low sensitivity iems (Final and Sony ier series iems to be precise). for
example iems that have 16 ohms impedance but below 100 db sensitivity. All ba and hybrids sound amazing and iems without the
mentioned issue as well. A force gain switch could have solved this niche problem.
3. Lacks wow factor. Won't make you go crazy and head over heels at first listen. Slow charmer
4. Battery hog. I have not faced any compatibility issues myself and it has been perfect from day one but in your system may turn out
otherwise especially in old hardware
5. Provided cables are very stiff. I am using a super flexible short paracord cable instead
Umm, I've probably written the full review in the pros and cons sections :cold_sweat: But TLDR- Good option under 200 usd range. This is Questyle's cheapest offering and don't expect it to topple their top tier stuff but Questyle's natural charm is still present here. Highly recommended if you are looking for something very very small yet powerful. I am thoroughly enjoying mine :gs1000smile:

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also some user have faced issue with usb 2.0, have you tried with with usb 3.0?
I'm torn between M12 and Sony NW A55...
If I only consider technicalities... which one should I get ?
Iem : Campfire honeydew , Final A4000
Source : Mostly use Tidal from a usb 2.0 phone.
NW A55 sounds more organic (Sony magic) but M12 is much superior technically. Also more powerful.
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