Home Amps JDS Labs ATOM HEVI Review – ATOM Got An Upgrade?!

JDS Labs ATOM HEVI Review – ATOM Got An Upgrade?!

The original ATOM was a fantastic product, is this version even better?

by Stuart Charles Black
Published: Updated:
>AFFILIATE DISCLOSURE: As an Amazon Associate I earn from qualifying purchases. As an eBay affiliate I earn from qualifying purchases.

Don't forget to share if you found it helpful!

Shout out to John Seaber over at JDS Labs for reaching out and offering to send me a custom engraved unit. I would also like to thank Jude Hopper (also of JDS Labs) for his support in years past. I appreciate it more than you know!

Greetings mate and Welcome aboard.

Stuart Charles here, HomeStudioBasics.com helping YOU make sound decisions leading to a beautiful audio experience that will make you fall in love with music (NOT gear) all over again, so…

Before we get into the JDS Labs ATOM HEVI Review, grab a snack, sit back, and relax;

You’ve Come To The Right Place!


Price: Check JDS!

In The Box

16VAC Power Brick



  • Frequency Response, 20Hz-20kHz: +/- 0.01dB
  • SINAD @ 2VRMS, 1kHz: 119 dB
  • SINAD @ 50mV, 1kHz: 90 dB
  • SNR (20-20kHz): > 122 dB
  • IMD SMPTE: -95 dB
  • Noise (20-20kHz): 1.99 μV
  • Crosstalk @ 10kHz 150 Ω: -92 dB
  • Input Impedance: 10k Ω
  • Output Impedance: < 0.7 Ω
  • Channel Balance: < 0.6 dB
  • Max Continuous Power @ 600Ω: 136mW (9.05VRMS)
  • Max Continuous Power @ 150Ω: 545 mW (9.04VRMS)
  • Max Continuous Power @ 32Ω: 1 Watt (5.66 VRMS)

I’d like to start out by saying that John Seaber told me, through email, that the ATOM Hevi is pretty much identical in specs to the original.

As for performance, Atom Amp+ Hevi is built on the same circuit board as Atom Amp+, so all published specifications are still valid. “Hevi” is purely a mechanical upgrade.John Seaber, JDS Labs



Out of all the companies I’ve dealt with over the years, JDS is the one I have the most respect for.

I outlined why in this video, but in short, it comes down to their ethos as well as their steadfast dedication to science and simplicity.

Contrary to what some may tell you, there is no need for thousands of different amps and dacs that all do the same exact thing.

A few are perfectly fine, and JDS seems to understand that better than anyone I’ve come in contact with.

Put another way,

instead of continuing to flood the already oversaturated market with endless amounts of DACS and variations of the same thing (as most other companies do), JDS decided to actually listen to user feedback and improve an already existing product.

Strange concept, right?

With that said,

what’s the deal with the new ATOM HEVI?


Well, as you may have guessed from its name, the HEVI improves on the original design of the ATOM by making it… heavier.

The original ATOM was incredibly light – to the point of concern although it was still in my top 2 recommendations overall (the other being FiiO’s K5 Pro).

In other words, I still thought it was a fantastic product and certainly worth a purchase without question. 

Even so,

I had many people come back to me saying how they couldn’t get over its plasticky cheap feel and I totally understood the sentiment.

In fact, I agreed. 

It was especially jarring considering how heavy-duty their original Objective 2 was.

I was fully expecting the original ATOM to be just as robust as the O2 and it simply wasn’t.

The Hevi is indeed much heavier and feels incredible in your hands.

The peace of mind of knowing that JDS rectified things is a huge deal, but the unit just feels exactly as you expect: solid, durable, robust.

As much as I loved the original for its clean, neutral sound, in the back of my mind I always felt a bit off about its build.

If you were wondering, the new kid is similar in overall stature and everything looks pretty much identical.


That said,

another huge improvement is the Volume Pot itself. This time around it’s a bit smaller but feels incredibly solid.

The pot on the original Atom was fine (kind of), but it almost felt like it was going to pop off like P. Diddy at a New Year’s Eve celebration.


In addition to that, again, it felt pretty cheap even to turn.


It feels great to turn and is also very sturdy.

So you won’t have to worry about it.

Front Panel


On the front, there’s your 1/4″ (6.35mm), the Volume Potentiometer in the middle, the gain button to the right of that, and the input button on the far right.

Connect your DAC using the outputs and plug the other ends into the ATOM using RCA or 3.5mm line. 

Now press the input button on the ATOM and plug your headphones in.

If you want to use the ATOM as a preamp into separate speakers, just run RCA to RCA or RCA to line from the outputs on the ATOM into your speakers of choice.

Then simply unplug your headphones and the sound routes through the speakers.

To switch back, plug your headphones in again.

Turn the Volume Pot and you’ll see a white halo light indicating power is present.

Back Panel


The back contains a set of RCA inputs and Outputs, a 3.5mm input, and the 16VAC power jack.

Only use the supplied adapter.

The ATOM is very flexible in that you can use it to connect separate studio monitors or speakers like the Presonus Eris e3.5.

Because it’s just an Amp, you’ll need a separate DAC to connect and listen to music.

That’s where the ATOM DAC comes into play. You can also use any DAC that outputs 3.5mm or RCA.

So far, I’ve used the FiiO K3, FiiO K5 Pro, and iFi Zen.



JDS ATOM HEVI ReviewThe same excellent sound is still intact here; clean, neutral, and with a low output impedance. 

A low output impedance (a number close to zero) ensures that the amp will always deliver the same (or roughly the same) output into any load.

In simpler terms, it means the amp is a consistent performer with a variety of headphones.

As with various types of audio electronics, if you have an output impedance that is too high, it can have a filtering effect.

This causes anomalies in the frequency response as well as diminished power output.

The ATOM HEVI avoids all that by simply utilizing a very low output impedance that will sound incredibly accurate and transparent with any headphones you may have.

Speaking of transparency, it may be just my imagination but I’ve always found that JDS products contribute significantly to that sense of experiencing what it may feel like to be in the studio space with the artists. 


I’ve talked about this with regard to the Objective 2 in years past and I got the same feeling with the ATOM HEVI paired with HIFIMAN’s Arya.

Yes, most of those sensations can be attributed to the Arya’s incredible sense of separation and thus superior resolution (to headphones in the mid-fi range), but the HEVI certainly provides the cherry on top.

You’ll start to hear so much going on in the recording that it may feel as if you’re catching a small glimpse of the actual space and every little minute sound and atmospheric wisp that the artist put into the song.

That said, it is subtle and depends on the track and how it was recorded.

Speaking of…

Potential Downsides


As nice as it is to have an amp like this, it’s not all sunshine and rainbows.

One of the main reasons why low output impedance isn’t always ideal is due to source discrepancies.

In other words,

how well the music was recorded, mixed, and mastered.

If the quality of the source is poor, an amp like the ATOM, in conjunction with your headphones, will absolutely reveal that and it might not make for a very pleasant experience depending on who you are.

The flip side is that sometimes it can really enhance the experience and you may even enjoy those quirky errors and abnormalities in the track.

I certainly do.

It’s what makes the music listening experience fresh and new as I’m always discovering new elements to older tracks I’ve long since forgotten about.

So in short,

tube amps sometimes mask errors and subtle artifacts in recordings while solid-state amps like the ATOM Hevi most certainly do not.

Output Power


The other thing I’ve always loved about JDS products is how powerful they are.

You’re getting plenty of headroom here without the gain switch.

I’m only on around 12 ‘o’clock on low gain and have a ridiculous amount of flexing left.

Rest assured this beast pumps out plenty of volume for 99% of headphones you may have.


*Inside joke*

In any event, before we give a final verdict, let’s go over some things I liked and disliked:

What I liked:

  • The durability issue is fixed. The ATOM Hevi feels great in your hands and is no longer a cheap-ish piece of plastic.
  • Power Output. Plenty of power for even the most demanding headphones.
  • Output Impedance. Low to ensure consistent output across any load.
  • Flexibility. Connect it to powered speakers and use it as a preamp.
  • Price to performance. Super affordable and a great overall value.
  • Sound. Honest, neutral, and transparent representation of the sound. Whatever the recording, the ATOM Hevi will deliver it uncompromised.

What can be improved?

  • JDS may consider a balanced headphone jack in the future for those pinky-out snobs.

Video Review

Don’t forget to leave me some love and subscribe! <3


Final Verdict


The ATOM Hevi is a welcome addition to JDS’ super lean lineup and continues the tradition of excellent, neutral sound at an affordable price point.

That said, JDS has since come out with ATOM 2, which, interestingly enough, provides some extra features and upgrades at around the same price.

Learn More:


Well that’s about it for today my friend! I hope you’ve enjoyed this JDS Labs ATOM+ Hevi Review and came away with some valuable insight.

Questions? Comments? Requests? Did I miss the mark on something? Please let me know down below or Contact me!!

If you love what I do here and want to support the blog and channel in a more personal way, check me out on Patreon and discover all the value I have to offer you.

Just want to make a one-time donation? Click here. Your support is greatly appreciated and helps keep this site running!

Does the Hevi sound like a can’t-go-wrong purchase? I would love to hear from you. Until next time…

All the best and God bless,





Can’t decide which headphones to purchase? Interested in a complete buyers guide outlining over 40 of the best options on the market? Click on over to the best audiophile headphones to learn more!!

Be sure to also check out my Reviews and Resources page for more helpful and informative articles!

Photo Gallery



Build Quality


Sound Quality/Neutrality




Power Output


Value For Money



  • Durability/build issue fixed
  • Honest, clean, neutral portrayal of music
  • Versatile, can be used as a preamp
  • Excellent price to performance/Great value


  • None

Don't forget to share if you found it helpful!

You may also like

Leave a Comment