Audirect Atom 2 MQA Portable Amp-DAC

Disclaimer:

I received the Audirect Atom 2 as part of a review tour in my country organized by Hifigo.com. I am not associated with either Hifigo or Audirect in any way and have no incentive whatsoever to write anything positive or negative about the unit. The Audirect Atom 2 can be purchased from Hifigo.com using the following link:

https://hifigo.com/products/audirect-atom2-mqa-hifi-portable-usb-dac-amplifier



Introduction:

Portable dacamps are more of a necessity these days as smartphone manufacturers have ditched the 3.5mm port. Let’s see how well the Audirect Atom 2 stands amidst the plethora of options available in the market. At 80 USD, the Atom 2 is definitely not on the cheaper side. I’m assuming the MQA certification, is one of the likely reasons for the somewhat high price tag.



The Atom 2 however, does look and feel like it's worth the money. The steel body with a splash of red feels premium and inspires confidence in terms of build quality. Given the shape, it seems to be more durable than the ddHifi TC35b, which in my opinion is a huge plus point. The Atom 2 is based on an ESS DAC chip, namely ES9281AC, and supports full MQA decoding. The Atom 2 has an LED indicator to indicate the type of file being played. The indicators are:

Red: 44.1/48kHz PCM

Blue: 88kHz – 384 kHz PCM

Green: 705 – 768kHz PCM

Yellow: DoP

White: DSD Native

Magenta: MQA



Gear:

I used the Atom 2 primarily with a Samsung Galaxy Note 10 Plus and just for the heck of it, connected it with my DAP, Sony NW-ZX507. Gear used was mostly IEMs, although I did use it with a Shure SRH1540 as well. In terms of power, the Atom 2 was able to drive my IEMs easily though it did seem to lack the power to drive the SRH1540 to its potential. In terms of battery drain, the drain wasn’t too much, though the unit did heat up quite a bit after using it for an hour or so.




Sound Quality:

The Atom 2 has a good presence in the sub-bass and mid-bass regions. There is good rumble and depth to the bass, with the bass thankfully not bleeding into the mids or overpowering the midrange. The bass is smooth and has a good texture with sufficient emphasis on the mid-bass, without making it sound too hollow or shallow. The midrange was great with vocals sounding lush. The good thing is that the mids aren’t overemphasized, thereby resulting in a good tonal balance and sounding coherent for the most part. The Timbre of the Atom 2 was especially smooth and evokes a sense of warmth that is usually not found on ESS chips. The overall sound, however, is not warm but more towards the neutral side. Those who complain of ESS sounding too bright should give the Atom 2 a try. The good thing about the Atom 2 is that it maintains the crispiness in the treble that one would expect from an ESS DAC, yet it doesn’t sound too bright or piercing. The treble is overall smooth and well extended. The Atom 2 is quite an analytical DAC that reproduces the tracks faithfully and will expose flaws in the source. If you have a poorly mastered track, it will sound bad on the Atom 2. However, a well-mastered track (especially MQA) will sound phenomenal on the Atom 2 (provided that the IEM is capable).



In terms of resolution, the Atom 2 is very capable and is capable of revealing details, though it does show its limitation in busy tracks, especially when compared to the internal DAC of the NW-ZX507. Atom 2 has a wide soundstage and the imaging is excellent. The Atom 2 has somewhat of a holographic presentation akin to the AM3D module on FiiO Q5s, with deep hitting bass and high precision in terms of details.

Conclusion:

Given the compact form factor, the excellent build quality, and the sonic performance, the Atom 2 is an excellent option as a portable DAC. It may not be very musical but it has excellent detail retrieval and a well-balanced sound signature. Perhaps, my only gripe is that in spite of being 3.5mm only, it doesn’t support an inline mic. Thus, making it less practical for someone like me who keeps switching between music and calls on my phone. Else, I’d definitely recommend the Atom 2 for anyone who’s looking for a portable DAC with excellent detail retrieval and a neutral sound signature.

Disclaimer:

The unit was provided was provided by HiFiGo in exchange for my honest opinions. This is not a Paid review. You can buy the same by clicking here.

Technical Specifications:

• 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).

The LED indicator details:

• Red: 44.1/48kHz PCM
• Blue: 88kHz – 384 kHz PCM
• Green: 705 – 768kHz PCM
• Yellow: DoP
• White: DSD Native
• Magenta: MQA

Build:

One Word for the Build…Excellent! The Body is made of steel and there is an attractive red coat on it makes it a fingerprint magnet as well. Rest…All is good.

Chain used:

Samsung Galaxy S10>UAPP/Neutron Player>Kinera Skuld/Kinera Norn/T3 Plus/Yuan Li and a few more.

Power:

Needless to say that all of these IEMs were relatively easy to drive and I have not tested any HP on Atom 2. I faced no issues while driving these IEMs.



Sound Impressions:

Bass:

The Bass is in great shape. Atom 2 adds Depth and Quality to the Bass response of the IEMs. The mid-bass is given a textured presence and also the bass doesn’t overpower the mids at all. So, there is that. Sub-bass became tighter as well. The rumbles were strong enough for me.

Mids:

The Mids are in balanced mode as well. Since there is no bass bleed, the vocals come out cleanly. The busy tracks were handled with ease and there was no congestion whatsoever. The separation was on point as well and the was sufficient air as well. Overall…Atom 2 has tight control over mIds as well.

Highs:

The Treble extension is handled diligently by Atom 2. This also depends on the chain that you are using but for all the IEMs that I used I felt that treble was well extended and non-fatiguing as well. So, a smooth presentation on the higher end.

Imaging and Technicalities:

As mentioned earlier, the imaging is great, the staging is wide, and the imaging is on-point.

Conclusion:

In the jungle of so many dongle dacs, it is becoming increasingly difficult to maintain a separate identity. Atom 2 has managed to do that with an extremely compact design and enough zing to drive most of the IEMs. You can go for Atom 2 if you are looking for:

• Good addition in Bass.
• Clean Mids.
• Smooth Treble.
• MQA.
• DSD512

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.

HEADPHONES:

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

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

MUSIC:​

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

XenosBroodLord’s Library | Last.fm

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.

PACKAGING AND ACCESSORIES:

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.

DESIGN, BUILD QUALITY, AND AESTHETICS:


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.

POWER DELIVERY:

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.

POWER CONSUMPTION AND HEAT MANAGEMENT:

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


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 (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)
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.

STANDARDS COMPLIANCE AND FUNCTIONALITY:

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.

SOUND:

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.

CLOSING WORDS:


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 (shenzhenaudio.com)

If you enjoyed this review, please consider checking out my blog at: https://medium.com/bedrock-reviews