Audirect Atom 2 MQA Portable Amp-DAC

General Information


Premium ES9281AC DAC Chip.
Full MQA decoding.
PCM up to 32-Bit/768kHz decoding.
DSD512 decoding.
Premium Crystal Oscillator.
Compact and lightweight.
Multi-color LED notification.
THD+N: 0.0004%.
Frequency response: 20Hz-40kHz.
SNR: 118dB.
Output type: 3.5mm single-ended.
Output power: ≥30mW(16Ω), ≥62mW(32Ω), ≥7mW(600Ω).
Fully Upgrade The ESS9281AC Pro Chip
The ESS9281AC PRO independent audio decoder chip produced by the global audio chip manufacturer ESS supports up to PCM/DXD (32-bit/768kHz), with an independent operational amplifier chip and advanced crystal oscillator, designed to achieve 118 dB DNR and 0.0004% THD+N Provide first-class audio performance. Let mobile phones/computers/game consoles also be able to HiFi up.

Enjoy MQA Lossless Music
Atom2 supports MQA renderer to listen to the sound of the original master tape by playing the MQA format! MQA obtains the original music signal in the recording studio. After the signal is recorded, MQA will "fold" the music signal to obtain a file size suitable for network transmission, which is called "Music origami". Let you experience high-quality listening enjoyment.
Wide Compatibility
MQA files can be reproduced on almost all devices with higher sound quality than CDs. When used with the MQA renderer, it can reproduce the effect of the original recording. Let you experience the rich music details in the recording studio. Coming in two types of connectors will meet the requirements for most devices. No worrying of compatibility issues.
Frequency Indicator Light Design
Despite the improvement of DAC chips, ATOM2 also put efforts in its innovative design. This product will change its colours according to different sampling rates. With a variety of colours, it adds a fun flavour to this little gadget.
18g Lightweight and Compact
Atom2 adopts the newly upgraded appearance one-piece copper-zinc alloy shell, highlighting the high-level texture. With a portable and high-end lightweight design, weighs only 18g, you can enjoy MQA lossless music anytime.
Automatic Gain Adjustment Smart Indicator
The prompt light on the body will change colour according to the decoded music format.
Red: 44.1/48kHz PCM
Blue: 88kHz-384kHz PCM
Green: 705kHz-768kHz PCM
Yellow: DoP
White: DSD Native
Magenta: MQA
If you want to listen to the perfect MQA sound quality master tape to light up the magenta light, please download roon or Audirvara player to log in to tidal and other accounts on your computer. There is only one app on the Android platform, usb audio player pro, just log in to your tidal account.
PS: After updating the firmware, 24/96 standards, ATOM2 can support mainstream game consoles, making your gaming experience better!

Latest reviews


500+ Head-Fier
Snack Sized
Pros: tiny form factor, standards compliance
Cons: average power consumption compared to most competitors (still much higher than Apple dongle), average sound, expensive for what it is

The Audirect Atom 2 is a compact digital-to-analog converter (DAC) and amplifier combination unit which connects to the transport device via USB-C. The Atom 2 was provided to me for review by ShenzhenAudio, where it is available for purchase for $79.99.


I have used the Audirect Atom 2 with the following headphones:

  • Moondrop S8
  • Moondrop Variations
  • Moondrop Quarks
  • SeeAudio Yume
  • Nicehck ME80


I have tested these headphones with local FLAC and Spotify Premium. Visit my page to get an idea of what I listen to:

XenosBroodLord’s Library |

I did not use the Atom 2 to play any Master Quality Authenticated (MQA) files in my evaluation and will not address MQA in my review other than to say this: I am strongly opposed to MQA and view its inclusion on any device as superfluous if not an outright negative. It is an anti-consumer, objectively inferior medium to lossless Pulse-Code Modulation. Please refer to Archimago’s review of the controversies surrounding MQA or GoldenSound’s video on MQA for deeper dives on the topic.


The Audirect Atom 2 comes in a rectangular deep blue box. The lid of the box is embossed with the Audirect logo, and technical specifications for the Atom 2, as well as Audirect’s corporate contact information, are provided on the rear of the box. The adapter is held in a foam mounting sheet inside the box. In addition to the Atom 2 itself, the box contains a user manual with appropriately brief instructions as well as a reference guide for the Atom 2’s indicator light.

The Atom 2 also comes with a USB-C female to USB-A male adapter. This adapter breaks USB specifications and does not have active circuitry to prevent backpower. I do not recommend using this adapter. If you must use an adapter like this with the Atom 2 or any other USB-C dongle DAC/AMP, I recommend the ones from CableCreation, which does have this important safety feature.


The Audirect Atom 2 has an ultra-compact block-like design. The body of the device is a polished slab of copper-zinc alloy with a chrome red faceplate. The Audirect logo and “ATOM 2” printed in white on the faceplate. The USB-C male connector protrudes straight out of the back of the device, and the single-ended 3.5mm jack is set into one of the side faces. There is an indicator light on the top face of the Atom 2 which displays different colors depending on the sample rate and format of the material being played back. “AUDIRECT CO., LTD.” is etched below the USB-C connector on the transport-facing side of the Atom 2, and the MQA logo appears off to the side of the connector.

The biggest problem with the Atom 2’s design is that its finish is a fingerprint magnet. In addition, the seam between the body and the faceplate accumulated a small amount of grime over the course of my evaluation. One final nitpick I have with the Atom 2 is the inconsistent font choices for different bits of text on the device. The faceplate logo, device name, and company name all use different fonts. It would have been more consistent to use the same font used in the logo for all the text on the device.


The Audirect Atom 2 is powerful enough to drive just about any in-ear monitor. I reach my typical listening volume with my phone’s system volume set to 58% with the hardish-to-drive Moondrop S8. On Windows, I reach the same volume at a system volume setting of 40/100.


The following power consumption measurements were taken while the Audirect Atom 2 was in use:

Audirect Atom 2 In-Use Half Volume Android.jpg

Audirect Atom 2 (In-Use)
The Audirect Atom 2’s power consumption while in use is roughly comparable to the Hiby FC3 and Meizu HiFi Pro. The power draw is higher than that of the gold standard for USB-C audio devices, the Apple dongle:

Apple Dongle.png

Apple Dongle (In-Use)
The Atom 2 does have a standby mode that kicks in when the device is plugged in without a connected headphone:

Audirect Atom 2 Standby.jpg

Audirect Atom 2 (Standby)
While heat management is adequate for a typical multi-hour listening session, the Atom 2 can get very hot if left playing overnight. It does cool off quickly once playback is discontinued in this scenario.


The Audirect Atom 2 correctly implements Android’s headset button standards. This means that the Atom 2 registers button presses on the attached analog headset and correctly triggers the appropriate behavior (play/pause, volume-up, volume-down, and voice assistant).

The Atom 2 also correctly sends connector status to the host device. When connected to a USB-C port but not connected to a headset, the Atom 2 is not accessible as an output device. The Atom 2 becomes the active output only when connected to a headset. Disconnecting the headset but leaving the Atom 2 connected to the USB-C port returns audio playback to the previously used audio output.

Both of the Atom 2’s connectors fit snugly and I did not have any issues with playback being discontinued by jostling the connectors in the pocket or otherwise disturbing the transport device.


While the Audirect Atom 2’s sound quality is adequate for portable use, over the course of my evaluation I could not shake the sense that it was slightly inferior in terms of resolution and detail retrieval to my favorite source device, the Hidizs S9. I routinely felt that transient delivery was slightly blunted in comparison. In a volume-matched(<.1 dB), sighted, non-instantaneous switching (1–3 second delay) comparison of the Atom 2 and the S9, this impression held true. There seemed to be slightly less definition to notes and less space around them, and transient delivery seemed slightly less precise. The difference is very small and only evident to me in a quiet home environment with the Moondrop S8, which is by nearly all accounts an incredibly resolving monitor. I discovered in my review of the E1DA 9038S that I could hear the differences between digital filters, and I suspect that is the reason for my perception.


The Audirect Atom 2’s primary differentiating factors are its extremely compact form factor and its laudable standards compliance. In most other respects, it is adequate but not exceptional.

The Audirect Atom 2 can be purchased below:

Audirect Atom2 MQA ES9281AC Chip Support DSD512 32bit/768kHz HiFi Por (

If you enjoyed this review, please consider checking out my blog at:


Headphoneus Supremus
Pros: Lush dynamic sound, bass weight and slam, natural full-bodied enough timbre, good macro resolution, good layering, vocal presence, more than decent amping power, energic but not agressive, not power-hungry, sturdy, genius design
Cons: Not the cleanest sound, treble isn't very sparkly and detailed, imaging lacks a bit of precision and deepness, decent amping doesn't mean its notably more powerful than my LG V30+ phone


TONALITY: 8.5/10


I follow Audirect company since its first BEAM release, which doesn't impress me much. So, it's just lately that I become quite an Audirect fanboi due to their incredible BEAM 2 dac-amp: an ultra-portable dongle with SE and (true) balanced jacks, a crazy power output of 240mw@32ohm balanced way, independent dual OPamp section and a highly dynamic sound with full-bodied tonality.
This explains why I was intrigued by the Atom2 even if it can't be an upgrade of the BEAM2, i was very curious to hear the sound difference between a dongle that use stock ES9281C DAC against one that use it with independent dual OPamp like the BEAM2. Will it sound THAT inferior? Well, spoil alert: no, it isn't. Its just less powerful and a bit less energic in dynamic range. Let's see why in this review.



(this is the packaging, nothing to write about apart that you got a USB-C to USB adapter)

''There is no genius where there is not simplicity''
-Leo Tolstoy

Simplicity can unlock practicality potential, and this is what the Atom2 achieves with it's all-metal T-shaped body. It's small, feels invincibly sturdy and once it's connected it embraces the body of your phone so you can forget about it. The fact the jack is at the side of it's body makes it even more portable and less prompt to unwanted disconnection. If i search devils in detail, i would say the jack is a bit cheaply embedded into the metal body, and it's made of plastic, but it doesn't seem to affect overall durability.


Plug and play, it get recognize by my phone automatically. For window, it seems Atom driver got automatically installed as well. Tidal too recognizes it and I can use exclusive mode to unlock it's full potential as well as listen to MQA music if I feel like it.

Capture d’écran (994).png

It must be noted that the Atom2 power on only if you plug a cable into it, so don't panic if it's not recognize before you do so.

Capture d’écran (995).png

As stated, the Atom2 decodes up to 384khz/32bit, to achieve this, don't forget to go in window sound setting or choose Bitperfect mode on your music player app like UAPP.



It's VERY important to understand that the stock ES9281C DAC has ''impedance adaptative power output'', and I feel lot of reviews out there don't know you can BYPASS it using a 3.5male to female adapter cable. This way, you have FULL 2vrms power output whatever you plug a 16ohm IEM with high sensitivity or 32ohm IEM with low sensitivity.

I barely always bypass low gain because even at low volume I do feel the soundstage is more open and the dynamic more weighty and impactful. Only with very sensitive IEM i will use it's lower output power because indeed, the Atom2 can deliver big power for it's size!

Simply put, the Atom2 is 2 times more powerful than Apple and Samsung Dongles (about 31mw@33ohm and 1vrms instead of 2vrms). It will not drive your Planar headphones properly, neither your 150ohm earbuds but will do well for anything under 64ohm.

For example, I don't consider the 64ohm Koss Porta pro as being the easiest to drive portable headphones and the Atom2 can make them explode of loudness if you feel like it. No distortion, clean and open with hefty punchy dynamic is the result of this nice pairing.

Now that you know you can unlock high gain for your low sensitivity IEM and Headphones, don't be afraid to lack power for anything that is meant to be portable and doesn't need a power amp to feed. 64mw@32ohm is plenty of power buuuuut it's nothing impressive for a portable DAC-AMP. In fact, my LG V30+ delivers 2vrms too, making it as powerful (on sheet) and well, supposedly canceling the need of using an Atom2 as well! But it's not that simple and the Atom2 still can deliver slightly louder sound at max volume, as well, amping isn't everything but I will do a proper comparison of those 2 anyway later.


I do a serious battery consumption test with my phone at 100%, playing music non-stop at high volume with my Koss Porta pro hooked to the Atom2. I must admit the result surprises me a lot! After 6 hours my phone was at 50%, and after 10H it was at 10%. So depending of your phone stock battery life and the apps that you use etc, you can forget about the Atom2 power demand, which is surely inferior in consumption to using your own phone audio output.

(using Final A8000, UM 3DT, HZsound Hearth Mirror, Audiosense T800 and Koss PortaPro)


TONALITY is what I would call lush neutral with slight bass and low-mid treble boost. Natural as whole, hefty in macro-dynamic, it's a compromise between fun and mature tuning and I think it nails it very well. This is a versatile tonality that doesn't over-boost any section, it isn't cold nor analytical and doesn't try to force micro-details to pop up in your face. Treble isn't the most extended and airy but neither lacking or dark. Low, mids and highs sound full and well-sculpted in dynamic range. The bass is very well delivered, avoiding this common sub-bass roll-off that stole your precious rumble extension, it gives extra dynamic fun to the sound as well as warmth to male and female body.

RESOLUTION is very good, especially in terms of sound layers extraction which are well articulated and emphasized. The Atom2 didn't expose lot of secrets micro-details and perhaps have some sort of ''Slow linear PCM filter'' that smooth ultra highs and stole some sparkle and highs decay as well. What helps the sens of clarity is the nice transparency of sound layers as well as clean enough background.

TIMBRE is smooth, gently textured, just a hint fuzzy bright, so this isn't the type of DAC-AMP that will boost upper mids sibilance of aggressively bright IEM.

IMAGING is good but not ultra-crisp and revealing and it will show it's limit with very busy tracks. It's better in layers separation than complex spatiality positioning.

NOISE FLOOR is sure better than a phone but not perfect black. Silence isn't 100% pure, more like 95%.

MUSICALITY is very well done and do not overemphasize the technical aspect of the sound, it avoids a plain neutral approach to add dynamic weight to it's tonality. It's both accessible and versatile, with nothing distracting like uneven tone or timbre, overly bright-edgy treble boost or overly boomy bass boost. Lush, full-bodied, thumpy in dynamic, and smooth in the treble, the Atom2 takes full advantage of stock ES9281C DAC by keeping it real to its nature. Both bass and vocal (mids) lovers will enjoy its tonality, only perhaps the die-hard treble-analytical audiophile will find it not enough sharp and detailed.



VS LG V30+(ES9218P DAC/125$ used price)

In terms of power output they deliver both 2vrms but the Atom2 can achieve slightly louder sound and notably more powerfull dynamic heft.

TONALITY of ES9218P DAC tuned by LG team is more organic and warmer, as well as flatter in the bass department and less treble extension-presence. Darker than Atom2 we can say. Both bass and treble extend in a fuller and more natural way with the Atom2.

TIMBRE is smoother, darker, less textured and less transparent.

RESOLUTION is notably inferior in detail retrieval, clarity of micro-definition, their no air or silence within the sound space so it feel hollow compared to Atom2 which extracts more sound info.

IMAGING is very flat in layers, lacking precision and space between instruments. Atom2 is more open, holographic, precise and deep.

NOISE FLOOR is higher with the V30+ and makes it sound way less clean than Atom2.

MUSICALITY lack dynamic weight and impact as well as bass extension-rumble, making the V30+ sound dull and overly laid back in dynamic and compressed in sound layers. Atom is just a hint brighter because V30+ is overly dark in the treble section, it's sound presentation is livelier, more open in imaging-soundstage and immersive.

VS TEMPOTEC BHD (Dual CS43131 DAC/70$)

Firstly, the BHD has a 2.5mm balanced output and delivers near 2 times more amping power than the ATOM2.
It has as well volume control buttons. In terms of design, it's less compact than the Atom.

TONALITY is more vivid neutral compared to warmer and bassier Atom2. The sub-bass of BHD feel more rolled off as well as overall bass impact and weight lighter. BHD is colder and more analytical, the treble is notably cleaner and sharper.

TIMBRE is thinner a bit more artificial with the BHD, but more transparent and less grainy than Atom2.

RESOLUTION is crisper, more transparent and detailed. Cleaner, with airier treble, but less natural and lush than Atom2.

IMAGING is more precise and spacious, making the Atom2 feel compressed in layers and lacking deepness.

NOISE FLOOR is cleaner with the BHD, so we can feel better ''silence'' between instruments.

MUSICALITY is less appealing to my ears with the BHD, due to cold tonality and thin timbre as well as lean light bass.

VS AUDIRECT BEAM 2 (Dual OPamp+ES9281C DAC/140$)

OK, this is my favorite do-it-all-on-the-go dongle, especially when used balanced way, but it cost 60$ more than Atom2 so it's not really a fair fight. Though they both use a single ES9281C DAC, the BEAM2 bypass implemented amping DAC chip with Dual OPamp for true balanced output.
Both balanced and single-ended output deliver higher amping power, 110mw@32ohm for SE and 240mw@32ohm for balanced compared vs 64mw@32ohm for the Atom2.

TONALITY is very similar, more balanced and less warm and boosted in mid-bass than Atom2.

TIMBRE is more transparent and nuanced in texture, cleaner softer. Hint thinner due to less bass warmth.

RESOLUTION is notably better, making the BEAM2 sound more open and revealing.

IMAGING is from another league here, with more precision and accuracy in instrument placement as well as clean space to dig in.

NOISE FLOOR is very similar, not completely black but micro harmonic distortion seems to stole more silence with the Atom2.

MUSICALITY is more open and immersive as well as holographic and revealing with the BEAM2, without sacrificing bass impact nor sounding cold or analytical. It's the best of both worlds, like mixing Atom2 and BHD.


With a very practical design, the Atom2 becomes a siamese brother to your phone and makes you forget about it's presence. With it's sturdy metal built, it promises long durability.
Though priced at 90$ it might not be very competitive in sound value and hard to justify to buy to those owning audiophile phones like the LG V30+, V50, V60, the Atom2 compensates what it lacks in TOTL technicalities with a lush immersive and very dynamic and well-articulated musicality.
For those that we're afraid it's Sabre DAC will deliver a cold crisp sound in the vein of ES9018Q2M and ES9038Q2M DACS, be reassured, the Atom2 aim for naturalness instead of clinical rendering.
All in all, the Audirect Atom2 is a great DAC-AMP with a very versatile sound and decent power output, but if you need more than 64mw@32ohm, you might wanna go Audirect BEAM SE that has 2 times more power output for 10$ more.


PS: I wanna thanks again and again HIFIGO for sending me this review sample. As always, i'm 100% independent of mind.
You can buy the Atom2 for 90$ here:
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Kathiravan JLR

New Head-Fier
Audirect Atom 2 – Clean And Compact
Pros: Excellent Sound stage in all dimensions
Clean and Smooth Sound
Nice Separation and Resolution
Functional Design
Power Draw
Cons: Power Output
Win 7 Compatibility
Hilidac or Audirect are the chinese audio manufacturers producing a wide range of DAC AMP and they haven’t been releasing any products for some time and now they awake and released the Atom 2 single ended DAC with MQA decoding, DSD native and 32 bit768kHz. In this review lets see is this new product relevant in today’s market with a lot of budget options already prevailing.



This unit has been provided to me as a part of a review cricle organised by HiFiGo. I thank the team for organising this circle and giving this nice opportunity to test out the audio gears. I have not been influenced by any means to manipulate this review and hence the views are completely mine and it may vary to your observations since the source and preference changes from user to user.


>Premium ES9281AC DAC Chip.

>Full MQA decoding.

>PCM up to 32-Bit/768kHz decoding.

>DSD512 decoding.

>Premium Crystal Oscillator.

>Compact and lightweight.

>Multi-color LED notification.

>THD+N: 0.0004%.

>Frequency response: 20Hz-40kHz.

>SNR: 118dB.

>Output type: 3.5mm single-ended.

>Output power: ≥30mW(16Ω), ≥62mW(32Ω), ≥7mW(600Ω)

Specifications Credits: HiFigo


The design of the Atom 2 is pretty minimalistic and simple. In other words i love the design language of the Atom 2 , they did it neatly and precisely. The build is made of steel and looks very premium in the hand and has some nice weight. The weight seems to be around 18 gms and gave that premium weight factor to the overall build. There are two versions available namely the Type C and the Lightning one for apple users.

The branding is done nicely in the bottom portion with a red background and the type c connector on the top portion. The led is situated in the below portion and lights up very brighter when the room lights are switched off which is quite disturbing. The 3.5mm jack is situated on the side of the DAC and is easily accessible when the DAC is connected.

The USB A connector is also encased in the aluminium casing which looked quite sturdier. There is also a USB A to Type C cable which I haven’t received since I got this as a review unit from my review circle.


This Atom 2 doesn’t support the Windows 7 and lower version which is pretty disappointing which just made me test out this DAC only via my iPhone.

The Atom 2 has only the single unbalanced output

The overall sound output is very clean and smooth. The low end is present evidently even though they have the ESS Sabre DAC which has that typical ESS sound signature which is pretty neutral to bright. The power output is however on the lower side where they are quite efficient for high sensitive iem but for power demanding headphones or the planar earphones like the Tin P2.

The noise floor of the Atom 2 is pretty neat and I have tried all the iem and have noticed no hiss in the background which is pretty nice.


The low end is the surprising factor here. They have nice bodied bass and impactful bass in the atom 2. The overall low is nicely textured, resolved and has nice separation. If you are having any nice warm sounding pair of iem then this will be a nice treat to you, where the bass separation and the texture got improved a lot

The sub bass is very nice here. It’s tight, punchy and has a nice rumble. The mid bass has a nice overall body and weight to the tone. Overall I loved the low end performance here despite the use of ESS dac since they are very balanced to neutral bright.


The Mid Section is the other sweet aspect here. The midrange is neither too forward or laid back, it just hits the right spot for me. The instruments have nice air and separation. Both the lower and upper mids are balanced pretty well and no harshness or sibilance is seen.

The mid range seems slightly on the thin side which also adds that clarity and detail in the mid section but I would have loved some more warmth and weight in the vocals. The female vocals especially need some weight eg: Taylor Swift Vocals. The clean power can be felt here in the midrange producing a lot of details and separation. Despite having the thin vocals especially female i like the midrange here due to that clean and nice separation.


The treble is the compromised part here. They sound pretty smooth and harsh. They have nice separation and air in between the instruments but the extension in the upper end is what is lacking. They extend average and also it depends on the capacity of the iem too. Overall the extension is average but the separation and the liveliness is presented well here. If you like more extended treble then this might disappoint you but when it comes to clean, fatigue free, smooth treble yet maintaining nice separation and air then this can be your best bet to get.


Since the bass is nice and impactful the soundstage headroom is very nice and wide. The sweet sub bass in this Atom 2 helped a lot in this expansive soundstage creating a nice overall headroom. The good amount of air and separation in between the instruments does a great job in creating that nice wide soundstage.

The Imaging is pretty nice here where you can easily point out the instruments and the vocals even in the busy tracks. The precise positioning of the instruments can be done very well here due to those nice thin notes in the midrange which eventually helped in the clean sound output in the midrange.

The overall separation and the resolution is pretty nice here which created that nice sense of big soundstage and precise instruments positioning.


The power is the next compromising factor here since this has very nominal power output at 32 ohms.

>30mW – 16 ohms

>62mW – 32 ohms

>7mW – 600 ohms

The power output is pretty average and hence if you are using this to drive some power hungry cans or even some earphones then this might not suffice you. Even while using the in-ear monitors with nominal sensitivity I need to keep the volume at 60 percent to hear in a normal environment which makes you raise the volume in the noisier surroundings.

One other advantage of this Atom 2 is that they don’t draw power from the source if the earphones are not connected, which is a pretty nice implementation to see.


MQA: This Atom 2 supports the final fold of MQA but i haven’t tested it out since i still can’t find a big difference between the FLAC and MQA

APP: The Atom 2 uses the UAPP support to utilise the high bit rate file playback and Apple users can enjoy the direct clean output.


The device has a light indicator to show the playback rate. The following are the indications:

Red: 44.1/48kHz PCM

Blue: 88kHz – 384 kHz PCM

Green: 705 – 768kHz PCM

Yellow: DoP

White: DSD Native

Magenta: MQA


Atom 2, the latest dongle DAC option from the Audirect brand is a pretty nice and recommendable one. The Atom 2 has one of the clean and smooth sounding dac available in the market yet without compromising on the other technicalities. The DAC itself is made robust and neat. The design of the Atom 2 is very nice and functional where they don’t dangle, instead they look fixed and neatly attached to the device’s port. The power draw is minimal and heating is very much negligible in my testing. The bass response and the soundstage is what I liked a lot in this despite the use of the ESS dac and that sub bass tightness is nicely done here. Overall I liked this product a lot and if you want some clean, warm and smooth sounding dac with minimal and functional looking then this is the DAC you need.


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