JDS Labs Atom Amp+ Hevi Review

JDSLabs Atom Amp+ Hevi

Sound performance

For the purpose of this review, I used the Beyerdynamic DT900 Pro X, the Audeze LCD-X, and my good old Sennheiser HD-800S. For the source, I chose the Hifiman EF400, the FiiO M17, and a old but faithful EarMen TR-AMP. All files were streamed from Spotify for convenience, Apple Music for Hi-Res source, and my own library for local tracks.

Overall Signature

Almost everything has been said by my colleagues the last time, but I’ll try to add my own impressions here – I’ll put in italic everything he said, for readability purposes.

As Yagiz pointed out in its review, this amp follows the same path carved by the first O2 Amp: straight, colorless, end-to-end amplification. It is neutral, clean, and transparent […] and the brand managed to upgrade a device that was already brilliant. Atom Amp+ is resolving, revealing, and clean, even at nearly max volume. It reflects the source and the track, without any coloration.

Paired with my HD800S the result was more than compelling and I can’t phantom how an amp this small could driver those massive cans with such ease. Last time, I was blown away by the value proposition offered by the SMSL HO100, but I found the Atom Amp+ Hevi to be on a superior level – at least with this specific headphone. I couldn’t hear any hiss or distortion, even on high gain*. It punches way above the price tag [and] at 99 USD, this amp is basically a steal -* can’t agree more on that, even if the Hevi is now… $20 USD more expensive.


The midrange is slightly recessed yet articulate, clean, and airy. Upper mids have great control and the extension is just brilliant. The treble range is breathy and clean with great extension to the top octave. The control is very good across the spectrum, there is bleeding, no overlapping anywhere. No peaks, no dips, no sibilance. The amp also handles congestion well thanks to the wide stage. PRaT is excellent and technical-wise, this amp acts as if it is priced in a much higher price bracket. You can’t go wrong with it.

In addition, you get that awesomely black background typical of post Objective2 amps, giving you tight, punchy lows and low-mids. In fact, even compared to my Chord Mojo 2 and Shanling H7, the Atom Amp+ Hevi held the upper hand 90% of the time, even more when paired with a high-end source like the A&K CA1000T. Paired with the Audeze LCD-X, the combo makes for a solid combination with deep bass and excellent voice rendering – even more if you can stick to 1X gain instead of 4X.

As expected, there is no fun in the design. It’s an amp that intends to push-pull the sound as close as possible to the original source. With good records like Tell-Me from Rohey, it’s almost life-like, but with old tracks, the experience can be sub-optimal, even deceitful since the amp magnifies every glitch and flaws of your music…

Layering, resolution and instrumental separation are all wonderfully done and if compared to the Element, the Atom feels like a downgrade, it’s hard to find anything as compelling, available in this $100 bracket.



Highs: Crisp and precise, the Atom Amp+ presentation remains rigid but non-fatiguing, delivering one of the best highs I heard on the Audeze LCD-X – funny pairing but it works. The amplifier’s transparent design lends a natural and airy quality to the highs, ensuring that even the most delicate nuances are reproduced faithfully. And with a little to no volume push, the JDS is an amazing choice for those seeking a transparent/revealing sound signature.

Track : Poly – Thylacine

Mids: top-of-the-line layering and dynamic. Voices have always been good on JDS Labs amps, and the Atom Amp+ is no exception to this tradition. This is especially true with big cans and hybrid IEM, who love its large power reserve, but even paired with classics like the Meze 99 Classics, the small amp delivers superb vocals, almost effortlessly.

Track : Wanderer – Mogli

Lows: impactful. In this price/size range, the JDS is almost unmatched in terms of bass. The cleanliness and control feels almost uncanny and paired with a solid headphones the bass remains tight and impactful at any given volume. It’s never bloated or overpowering, whatever the volume, allowing the amp to deliver clean bass while maintaining its exceptional layering and remarkable separation.

Track : Way down we go – Kaleo



Once more, the Atom Amp+ (Hevi) earns my full recommendation as THE best headphone amplifier for anyone seeking a sub-$200 model. A no-brainer, outperforming many, if not every, amp available in this category at the time of writing.

Sure, the Hevi version is just a cosmetic revamp of the regular one, but for anyone sensible to that, the various additions like the aluminium top-case, or the sturdier volume control, will definitely be a worthwhile $15 invest.

Add to that JDS Labs renowned built quality and after-sales service, some nice features like the auto-mute headphone out, and yes, this amp goes directly into my recommendation list. A sure choice!

Pros :

  • amazing sound quality
  • great build and small footprints
  • affordable price
  • lovely volume control


  • heavy power supply
  • not much in this price range

Page 1: about JDS Labs

Page 2: Usage, Bundle, Specification

Page 3: Sound performance

4.5/5 - (20 votes)

A nerdy guy with a passion for audio and gadgets, he likes to combine his DAC and his swiss knife. Even after more than 10 years of experience, Nanotechnos still collects all gear he gets, even his first MPMAN MP3 player. He likes spreadsheets, technical specs and all this amazing(ly boring) numbers. But most of all, he loves music: electro, classical, dubstep, Debussy : the daily playlist.

1 Comment

  • Reply December 13, 2023

    David Polombo

    I recently purchased a Marley turntable with built in preamp and Bluetooth. I have the Audoengine A1 speakers as my desktop speakers.75% of the time, I simply connect the Bluetooth of the player to the speakers. This combination sounds fantastic. However, there are times where I prefer to listen through my HIFIMAN HE400SE planar head phones. Unfortunately, like most planar headphones, they are difficult to drive. Such was the case with myself as well. Even with the volume turned up tp 100%, there was still not enough power to adequately power the headphones. Obviously, my next step was to look for a good headphone amp but did not want to spend a lot of money. After doing some research, my choice was the ATOM+….All I can say is WOW!!!!!!!. My headphones have never sounded so good. I am now hearing notes that I never heard before from songs I listen to all the time. I may never listen to my turntable without my headphones ever again. This amp ROCKS>

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