This part of our review will be divided into two sections for the packaging since two boxes arrived. One was for the DAC+ while the other was for AMP+. Let’s begin with the DAC+ box.
When the DAC+ arrived for our JDS Labs Atom+ Stack review, we noticed JDS Labs’ unique approach to packaging. They went for a simple but practical packaging style and chose a sturdy, durable box that protects the product inside.
In fact, their box reminded us of DIY kits, which is pretty interesting. But long story short, their packaging is straightforward.
We can’t really see the difference between its packaging from the original Atom. Plus, its 15VAC power adapter feels quite heavy too.
For its accessories, the Atom DAC+ features a brilliant USB-A to B cable. It’s finished and custom-made with gold-plated connectors, plus a TDK ferrite core. This improves jitter performance and rejects noise.
Moreover, the company even included a rocker power switch in the box to switch the Atom DAC+ on/off. And, they added a stamped inspection card in the DAC and AMP box. This has become a standard inclusion every time you purchase the product.
The card states that the unit you’ve just purchased was inspected twice and assembled ideally.
Now with the Atom AMP+, it has some similarities with the Atom DAC+ since the packaging is straightforward too. Inside, you’ll have the AMP and the 16VAC power adapter that’s something present with the JDS Labs gear.
Both the Atom DAC+ and Amp share the adapter, then they occupy around four slots instead of two. This is because of the huge size of the adapter.
For the accessories, you won’t find any of these. You’ll only find the adapter and product together with the stamped inspection card.
Now, our JDS Labs Atom+ Stack review will focus on their design and functionalities.
JDS Labs Atom+ Stack Review – Design and Functionality
JDS Labs Atom+ Stack: Atom DAC+
Technically, the Atom DAC+ features a small footprint and it won’t take a lot of space on your desk. Not only that, but it’s lightweight which makes it all the more convenient.
Though it seems like there isn’t any physical difference compared to the earlier generation, there actually is. We saw better structural integrity and increased rigidity when we held it. The plastic used felt stronger and thicker compared to the earlier generation.
For the input switch button, it felt smooth and tactile. Then, the gold-plated RCA plugs and various ports were solid and well-made.
While checking the product for this JDS Labs Atom+ Stack review, we saw four anti-slip rubber feet on both units. These do their job well and are low profile.
For its price point, it won’t get any better than it already is, build-wise. We greatly appreciate JDS Labs for doing this, and it’s actually a job well-done.
When it comes to its design, we can say that it’s pretty good. However, we think that the objective line was a bit too DIY-ish. Though when it comes to the products under the Atom line, these look elegant and simple at the same time.
Its white light ring design looked absolutely stunning especially at night. The light ring’s dimness was adequately thought of and it doesn’t strain the eyes.
Speaking of its layout, the front features an input switch button. It can be utilised to switch between optical and USB inputs.
On the DAC’s rear portion, you’ll find the RCA outputs, TOSLINK input, USB input, and a barrel-type power socket. What’s nice about it is that its layout is clean, neat, and easy to learn.
JDS Labs Atom+ Stack: Atom AMP+
For the Atom AMP+, it’s the best companion available for the Atom DAC+. The two share the same design aesthetics and build quality, which is another thing we appreciate from JDS.
Both their form-factors are roughly the same too. And like the DAC, the Atom AMP+ is just as light, and features a plastic chassis with excellent quality. Generally, we couldn’t see any case imperfections or assembly issues so kudos to JDS Labs for this.
When it comes to its layout, the unit comes with a volume pot with a subtle light ring around it. Plus, it matches the Atom DAC+’s front side with this specific detail, and they both look awesome when stacked.
If you look at the right portion of the volume pot, you’ll find two spring-loaded push buttons present. The input and gain can be changed swiftly with the help of those buttons.
Looking at the left portion of the volume pot, you’ll find a 6.35mm headphone-out port.
Checking the rear, you’ll see RCA inputs and outputs. There is also a 3.5mm input socket and the barrel-type power socket made for the 16VAC adapter. Its gold-plated plugs, as well as the sockets, feel solid and well-made like the DAC.
For us, the Atom AMP+ ticks all the boxes when it comes to its overall style, build, and design.
Key Features of the JDS Labs Atom+ Stack
Now, our JDS Labs Atom+ Stack review will discuss the different features of the product. Let’s see what makes it better than the rest.
Atom DAC+ Features
Clocked by MEMS Oscillators
The 45/49MHz MEMs oscillators with ±25ppm frequency stability clock the Atom DAC+ to reduce jitter.
The Atom DAC+’s XMOS based firmware handles and configures all functionality. With DFU support, the DAC+ will be compatible with future updates.
UAC2 and UAC1
Atom DAC+ supports up to 32/384kHz PCM over an XMOS based UAC2 engine. The company doesn’t claim that the product has measurable superiority of high sampling rates. However, the ASIO and UAC2 support will satisfy your needs for bit-perfect listening.
For UAC1 mode, you can activate it by using a UAC1 Fallback Cable.
The Atom DAC+ is powered by an optimised supply network. This works with an external AC transformer and ten regulators that ensure low ripple and consistent rail voltage.
After 15 minutes of inactivity, the Atom DAC+ automatically enters standby mode. At this state, its light ring and D/A circuitry powers down.
Differential Summing I/V Output
The differential output of an ES9018K2M DAC is paired with JDS Labs’ precision tuned and DC coupled I/V converter. It has three stages per channel or a total of six NJM opamps.
Atom AMP+ Features
Now, let’s check out the Atom AMP+’s features.
When you unplug your headphones, the Atom AMP+’s knob automatically adjusts the RCA preamp outputs’ volume. Doing this will allow you to have control over your powered speakers.
Ultra High Power
Most headphone listening only requires milliwatts, but the AMP+ utilises similar output buffers as JDS Labs’ flagship, Element Line. These buffers push 1W of clean audio per channel while keeping the AMP+’s power supply reasonably sized.
With dual inputs, you can connect up to two sources to the Atom AMP+. Choose between the RCA and 3.5mm input by simply pushing a button on the AMP+.
The Atom AMP+ is designed for desktop listening. It features relay muting to eliminate thumps and pumps during startup.
Dual Gain for the JDS Labs Atom+ Stack
The AMP+’s low gain of 1.0x comes with hand-matched potentiometres which are suitable for driving efficient IEMs. Its high gain powers demand full-sized sets with ease when paired with the Atom DAC+.
Top-notch Quality Performance
In our tests for this JDS Labs Atom+ Stack review, this product does offer top performance. JDS Labs’ Atom AMP+ is their most advanced analogue amplifier that offers top-notch performance from its star-grounded, 4-layer layout.
Let’s take a look at the products’ different specifications and what makes it click.
Atom DAC+ Specifications
To begin, the DAC+ has a frequency response (20Hz to 20kHz) of +/- 0.12dB and SINAD @ 1kHz, 20-22.4kHz that’s 112dB. The THD+N is less than 0.0004% while IMD CCIF (19/20kHz -6 dBFS) is -111dB. Then, SNR (20Hz to 20kHz) is higher than 117dB.
The product’s A-weighted noise is -109dBu with a dynamic range (A-weighted AES17) is over 120dB. The Atom DAC+ has a linearity error (-90dBFS) of -0.01dB and crosstalk (1kHz, 100k input) of -104dB.
Its USB jitter components @ 12kHz is -131dB while its maximum DAC line-output is 2VRMS. Plus, it has 4 layers for PCB stackup.
Speaking of its dimensions, it’s 12.7 x 13.5 x 3.55cm and weighs 8oz. For its digital input connection, it uses TOSLINK and USB, while the line output is an RCA.
Atom AMP+ Specifications
This time, the Atom AMP+ has a frequency response of +/- 0.01dB (20Hz to 20kHz). Then, its SINAD @ 2VRMS and 50mV (1kHz) are 119dB and 90dB respectively.
The AMP+’s SNR (20 to 20kHz) is over 122dB while IMD SMPTE is -95dB. Its noise (20 to 20kHz) is 1.00 μV, while crosstalk @ 10kHz 150Ω is -92dB.
Then, input impedance is 10kΩ while output impedance is less than 0.7Ω. Also, its channel balance is less than 0.6dB.
The maximum continuous power of the Atom AMP+ are as follows. At 600Ω it’s 136mW (9.05VRMS), while at 150Ω, it’s 545 mW (9.04VRMS), Lastly, it’s 1W (5.66 VRMS) at 32Ω.
The case also measures 12.7 x 13.5 x 3.55cm but it weighs 9.3oz instead. For its connectivity, it has a 6.35nn headphone output, RCA and 3.5mm analogue outputs, and an RCA preamp-output.
Next up in our JDS Labs Atom+ Stack review, we’ll see how the JDS Labs Atom+ Stack performed. And, if it’s just as good as what JDS Labs claims them to be.
Hands-on with the JDS Labs Atom+ Stack
Atom DAC+ Performance
Like the previous generation, the Atom sounded clean and clear. Nothing really changed signature-wise since everything sounded perfect without any peaks or dips.
Tonality was the same, the natural sounds of instruments were organic while the transients were snappy with excellent resolution. As we continued our tests for the JDS Labs Atom+ Stack review, we noticed some things with the instruments. These had a lot of air between them, were positioned adequately, and the stage didn’t feel congested or crowded.
For its distortion, it was below -120dB relative to the signal which makes it inaudible.
Checking out its bass, it was just as thick and powerful as it was before. That’s because it has the tools to offer a strong bass response. We felt the harmonics without any roll-offs, while the low-ends had good authority yet stayed within the limit without bleeding.
Mid-range was defined while the vocals were articulate and clean. It was pleasing to listen to jazz tunes from the past since this little box worked wonders to the sounds.
The upper-mids offered the same outstanding energy while staying in their designated grounds. And, these didn’t shine more than necessary.
Its treble extension was good as the previous generation too. Actually, we can even say that it might even be slightly better in its top octave.
The Atom DAC+ appeared to be a bit more linear and detailed especially in the treble region.
Atom AMP+ Performance
Its sound signature is like the Atom DAC+ since they’re both clean, neutral, and transparent even at max volume. It was able to reflect the track and source without any unnecessary colouration. The company managed to upgrade and improve a product that was already good.
Unlike the original Atom AMP, this is more neutral and natural with a bit of a coloured sonic. And what we liked about the latter is that it was thick and warm. It didn’t colour sound as much, plus had less hissing and noise.
Though it did sound a bit controlled and deep, we didn’t really hear any distortions. With that, we can say that it definitely punches above its price tag.
The bass was deep and fun with a lot of extension and substance. It was on the natural side, offering a good sense of depth and space.
For its mid-range, it was somewhat thick and warm. The Atom+ stack had a tendency of presenting less texture compared to other amplifiers. This way, it presented music more fluidly and with more emphasis on the track’s musicality.
It worked well with all music types whether it was rap, metal, classical, or EDM. The soundstage was large with a wide and deep presentation. Plus, its dynamics were perfect too.
The Atom AMP+’s treble was smooth and relaxed without a lot of emphasis on the highs. Although it wasn’t overly expressed, it was smooth in nature and never sounded boring.
In terms of the AMP+’s temperature, it never got hot when we used it. The product did its job well and we didn’t have any problems with it. For its price, it’s basically a steal.
JDS Labs Atom+ Stack Performance
The JDS Labs Atom DAC+ and AMP+ combined was brilliant which is what we expected. This neutral mix was an excellent conductor that worked as a bridge between the track and our headphones. Both units were highly capable of delivering a transparent, clean, and neutral audio which was great.
The Atom DAC+ and AMP+ were good benchmarks to find out how good our tracks were mastered. Of course, the stack’s audio results highly depended on the headphones we connected.
When we used headphones with a balanced sound signature, the stack delivered well-balanced audio. But when we tried highly analytical headphones, the audio highlighted the tracks’ mastering issues.
In terms of the stack’s technical performance, its transients were fast with harmonics that were easy to follow. That’s all thanks to the clean and transparent presentation of the Atom DAC+ and AMP+. These units combined delivered great resolution with highly accurate tonality.
Overall, this Atom+ stack delivered excellent performance that’s way beyond its price tag. With that, it’s easy to recommend to every audiophile around.
JDS Labs Atom+ Stack Review Summary
JDS Labs continuously develops the Atom line each year and finds ways to improve each product they launch. We appreciate the company’s efforts since there aren’t a lot of alternatives with the same performance and price range. JDS Labs is truly admirable for consistently offering products with excellent price to performance ratio.
For the Atom+ Stack, we were pleased with the DAC+ and AMP+’s impressive audio performance and well-constructed bodies. We also appreciate the products’ simple yet stylish design with the iconic ring light.
Overall, we were satisfied with this stack and we highly recommend it. To get your hands on the DAC+, it’s available for online purchase from the product page. The AMP+ can also be found on the company’sofficial site.