JDS Labs Atom Amp+ Hevi Review

JDSLabs Atom Amp+ Hevi

In this article, we review the JDSLabs Atom Amp+ Hevi, an upgraded version of the first Atom Amp+ selling for just $114 USD.


Disclaimer: JDSLabs sent us the Atom Amp+, free of charge, for the purpose of this review. In exchange, we’re going to give our honest opinion, as always.

About JDS Labs

Founded in 2007 by John Seaber (hence the name JDS) JDS Labs is one of the coolest audio manufacturer I know (and same could be said for John). Renowned for its unbeatable value-for-money systems – think chi-fi prices but US manufactured – the brand first begin with a mini headphone amp, based on Chu Moy’s open-source plans. With a few tweaks and a BassBoost mod, the first JDS Labs product was born: the CMoyBB. An headphone amp that not only gave fantastic results paired with an iPod Classic (I used mine with that purpose only) but also stood out from the crowd thanks to its “Altoids” casing – yes those were genuine mint candies box, filled with a amp and a 9V battery.

Then, a few years later, JDS Labs took another bold step forward, siding with NwAvGuy’s who just released its own O2 headphone amplifier schematic, in direct opposition to forums and audiophiles bias, followed by the ODAC a few months later. A daring move that prove fruitful, pushing John and his team even further, allowing them to expand and invest in better tools, like CNC machines, to create a whole new range of products namely, The Element – lovely DAC/AMP by the way, check our review.


But the true killer from JDS only came a few years later : the Atom Amp. A nifty little headphone amp, designed as a shoehorned version of the EL(ement) Amp, showing benchmark performance, at a super-low price. An amp that earned Linus praise in 2019 and Yagiz recommendation in 2021, in pack with the Atom Amp+ DAC – another great addition to their pocket-sized, desktop setup.

So when the brand asked if we were interested to try their new JDS Labs Atom Amp+ Hevi, I jumped in. Should you go with the classic one, or the Hevi version? That’s what we’ll find out today

Design & Build Quality


As usual with JDS Labs, build quality is absolutely flawless. as you can see in the pictures, our version has our logo on the top panel.

No gaps, impeccable junction, premium materials everywhere you see/touch, and a dense casing that exudes confidence once in your hand. It’s almost entirely made of CNC-milled aluminium, from the top-case, to the knob – longer now as we’ll see subsequently – and for just $114, you’d be hard-pressed to find another amp that feels as premium as this one.

I took out my SMSL HO100 for comparison, and if the Atom Amp+ looks equally good, once you flip it over, you’ll see that the bottom part is made of plastic instead of aluminium, leaving the upper hand to SMSL and its full-aluminium cover. Yet, that may be the rugged finish, the smoother knob volume, or the stiffer chassis, but I personally preferred the JDS on the long run.


On the scale, the Atom+ Amp Hevi is now twice heavier than the regular version (480g vs 260g), all thanks to its thicker anodized top plate. It’s a little taller than before 0.7cm, but apart of that, it shares the exact same dimensions with the regular version. Still, if you were compare that to the FiiO M17 and Q7 we previously reviewed, it’s almost feather-light for a desktop amp. The trick? With a separate power-supply, JDS Labs saved a lot of weight in the making, whereas brands like SMSL decided to include everything inside the case.

Still, this is an amp that should fit all and every desk with no problem, even paired with the Atom+ DAC – check Yagiz review, he tried the stack and was quite happy with it too.


The layout of the Atom Amp+ Hevi is quite simple. In fact, it’s the same one found on the regular version.

Upfront, you have:

  • 1x 6.35mm headphone out
  • a new, improved, volume knob
  • one button for the gain (1x or 4.5x)
  • one button for the input (3.5mm Line-in or RCA Line-in)


Meanwhile, in the back you get:

  • 1x RCA stereo input
  • 1x RCA stereo output (to work as a pre-out)
  • 1x 3.5mm line-in
  • the AC supply port (yes, this amp works with an AC power supply and not a DC!)

A simple I/O that should suit all basic needs, and should even allow you to plug another amp (like a power amp) in daisy-chain.


The JDS Labs Atom Amp+ Hevi follows the brand’s usual path, and comes with a very dire bundle – but that’s classical for JDS.

Inside, you will find :

  • the Atom Amp+ Hevi
  • the 16VAC power adapter
  • and… that’s all!

No 3.5mm to 3.5mm cable and RCA, which means you’ll have to buy one buy yourself. It’s not a big issue considering the price, but bear in mind that you’ll have to get those with your next purchase!


Last but not least, I’ve to point out that the box is made of recycled cardboard – a trend that JDS has been following for more than 10 years now – and how heavy the power supply is. Compared to your traditional AC-DC transformer, the AC-AC one feels like a behemoth.

Let’s plug it now.

The article continues on Page two, after the click here.

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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