JDS LABS ATOM Review: Budget desktop Amp Excellence

JDS LABS ATOM REVIEW

SOUND: 9/10
AMPING POWER: 9/10
CONSTRUCTION&DESIGN: 8/10
VALUE: 9.5/10

THE PLUS: Clean transparent sound, natural tonality, powerful, versatile gain modes, RCA In and Out,  precise volume potentiometer, small size, VALUE
THE SO-SO: Light plastic construction, so-so headphones jack

JDS LABS is an American audio company from Missouri, specializing in desktop and portable amplifiers as well as DAC-AMP. All their products are designed and manufactured in the USA, and this do not inflict on the price range of their product which stays in the budget realm.

Since 2007, this company impresses many audiophiles with their price-to-performance ratio that offer their amplifier and DAC-AMP, the JDS LABS Objective 2 that was launch in 2013 really put them on the map for the impressive power output it can deliver for such a small-sized amplifier.

Today I will review the most budget-friendly desktop amplifier of their lineup, the JDS LABS ATOM, a super small AMP+Pre-AMP that can deliver a very high output of 1W into 32ohm. Priced at only 100$, this amplifier is considered as the next-generation replacement for the Objective2 and promise clean neutral sound with black background floor even at high gain.

I only heard good things about this little amplifier, and after an audiophile friend of mine cannot stop praising it and suggesting it to me, I decide to contact JDS LABS and give this little fellow a try. In the sub-100$ price range, it’s extremely rare to find a serious trustable amplifier with stable performance and highly promising specs, this ATOM is one of them and perhaps the only one that we can fully trust, due to a 2 years warranty that comes with the products.

Let’s see in this review how the ATOM performs and if it can compete with a pricier amplifier like the Xduoo XD-05 and Xduoo TA-10.

You can buy the ATOM directly from official JDS LABS WEBSITE.

SPECS

• Frequency Response, 20Hz-20kHz +/- 0.01dB
• THD+N, 1kHz, 32 Ω 0.0008%
• THD+N, 20Hz-20kHz, 32 Ω 0.0012%
• IMD CCIF 19/20kHz 32 Ω 0.0002%
• IMD SMPTE 32Ω 0.0005%
• Noise, A-Weighted -114 dBu
• Crosstalk @ 150 Ω -87 dB
• Input Impedance 10k Ω
• Output Impedance 0.1 Ω
• Channel Balance < 0.6 dB
• Max Output @ 600Ω 125mW (8.68 VRMS)
• Max Output @ 150Ω 502 mW (8.66 VRMS)
• Max Output @ 32Ω 1 Watt (5.66 VRMS)

PACKAGING&ACCESSORIES

The ATOM comes in a shipping box that was rather heavy, which makes me think the amp is quite heavy. But all the weight came from the big power supply. The ATOM has its own little box. Nothing fancy, and no accessories apart from the power supply. At this price, I wasn’t even expecting a power supply to be included so no complaint here.

CONSTRUCTION&DESIGN

 

The ATOM has a simple construction, with a 100% plastic body. It’s impressively light and very small. The front panel has 6.35mm audio jack, a smooth volume knob and 1 button for gain and another button for input. In the back, we have RCA output and input as well as 3.5 line in. We can’t expect high-end construction at 100$, and what really counts here is quality of volume knob, which is precise in control and neither too loose or to tight in rotation, as well as the quality of button, which is perhaps the only fragile part of the device. The quality of gold plated RCA connectors are good, but perhaps I would have preferred a 6.35mm headphone output of better quality, as this one is made of plastic. It must be noted that the ATOM is so light it can easily move if you pull on your headphone cable if it falls on the ground, the rather cheap plastic body might break easily, but not the PCM board inside.

The INTERFACE is extremely simple, you either use the ATOM as Pre-AMP by plugging your active speaker to it’s RCA output, or as an amp, using RCA or 3.5mm input.  You can have 2 types of input, which you select by pressing the input button to choose between RCA or 3.5mm input. You open the ATOM by turning volume knob, a light will appear around the knob. You then choose your gain mode by pressing the button or not, depending of your need. An interesting feature is a fact that RCA output will be only active when you unplug your headphones, so you do not have a bad surprise if the volume was adjusted highly for demanding cans.

The ATOM use a nice quality custom Alps 15A potentiometer for volume control, this is quite a big deal to have highly precise volume control with an amplifier and this potentiometer have a wide array of step control so you can select exact volume level you want, no big step as it can be found with Xduoo XD-05 with unprecise volume control until a rather loud volume. This mean you have very low channel imbalance that can only occur at extremely low volume, barely audible level.

Inner construction implemented the same output buffer than the one found in their flagship Element line, this permit to push the high level of clean power. As well, the PCB board use 4-layer, star grounded layout, which permits an advanced power management with very low distortion.

PERFORMANCE

It makes about 2 months I use daily this little amp, mostly hooked on my Xduoo X20 DAC line out, which is plugged to my SurfacePro 3. The X20 uses a reference Sabre ES9018 DAC, that delivers flat, clean and detailed sound without any coloration. The ATOM love this type of DAC, which permit to show what he’s capable of in term of low distortion and black background. I use a wide array of IEM and Headphones with this AMP, from Meze 99 NEO to Hifiman SUNDARA to super sensitive Audiosense T800 to hard to drive Final Audio E5000 and TinHIFI P1. Unfortunately, I cannot test the Pre-AMP as I do not have active speakers.

The ATOM can deliver up to 1W @ 32ohm at high gain, as well, it has very low impedance output of 0.7ohm which makes it a versatile amp for both sensitive earphones and high impedance headphones. It’s SINAD of 114db, which is impressively high, promises a very clean and transparent signal with a very low distortion level. It’s signal-to-noise ratio is impressively high and can go up to 124db at high gain, which promises a very lively dynamic range and articulate imaging. The crosstalk too is very high at 87db, which will inflict in stereo separation accuracy. All these specs are way above what we could expect from a 100$ amplifier, and when you look at the size of ATOM you are clueless about how such performance can come from such a small device.

For those who was struggling to find the perfect versatile amplifier that can properly drive both your IEM and Headphones without sound compromise should it be in term of clarity or amping power, the ATOM sure is a dream come true. I am one of those people, either unsatisfied by the level of distortion of an amp, it’s too high impedance output for sensitive IEM or lack of clean power for more demanding headphones. For me, the ATOM act like 2 different amplifiers, well, we can say 3 because of it’s analog output as pre-amp too, what I mean is that low gain is notably less powerful at 1db again it’s +6.5db for high gain, but both gains is surprisingly clear too, you can drive your IEM at high gain and low volume, and to some extent, it will give a slightly different flavor, more weighty and dynamic sound, but less nuanced and balanced too.

In fewer words, I would describe the overall sound as neutral without any lack or boost in any frequencies range, smooth in timbre which gains in transparency, tonally natural and slightly liquid. It’s not an edgy, cold or bright sounding amp, it even has an analogic feel to its sound, hint of warmth in timbre that avoid grainy or dry presentation.

LOW GAIN

At low gain, I can drive properly any of my earphones, should they be sensitive or hard to drive, they will be push properly. Still, I will use high gain for some exceptions like the TinHIFI P1 or Final Audio E5000. The ATOM is flat, clean, natural and transparent in it’s rendering, it does not boost any specific frequencies range, neither it’s roll-off in the bass, mids or highs. The background is impressively clear and to my ears, the presentation as slight organic feel to it, as is cohesive in tonal balance and make instrument layering flow more effortlessly, hard to explain, but any IEM I use gain in timbre body but not in texture grain, as well, soundstage expand especially in tallness, which is rarely improved in earphones headroom. As a fully analog amplifier, the sound clarity isn’t artificially sharpened, it’s smooth, airy with weighty natural dynamic. To me, this is a neutral amp that keeps a sense of laid back musicality, without forcing anything and letting the music flow with great fluidity.

After listening to the DITA FEALTY directly from my Xduoo X20, I hook it up to the ATOM and the sound difference is found especially in timbre richness, which have a more 3D presentation as well as the soundstage that expand drastically. The other improvement is in the bass department, which is thicker, weightier, better define in extension. Instrument separation gains in space too and the whole dynamic is less bright and cold, offering a fuller more balanced sound. The X20 delivers 210mW @32ohm from its unbalanced output, which is inferior to the ATOM.

When it comes to very sensitive earphones like the capricious Audiosense T800, the 0.7ohm of impedance isn’t enough low and does interfere with sound dynamic, offering thicker timbre that affects instrument separation space and layering, making the T800 more shape and recessed in mids. Their no hissing, but clarity feel saturated and less accurate. This time, it sounds better directly plugged into the X20 which deliver very low impedance, around 0.1ohm. It must be noted that the T800 are unstable IEM that have sound imbalance with 75% of audio source I use, all due to impedance interference.

HIGH GAIN

This is a powerhouse, at 1W of full output, the ATOM can drive easily everything I own, and I’m very demanding about the amping obsession as I tend to use portable amp even for 32ohm earphones. The sound quality is near the same than low gain, perhaps more energic in dynamic and slightly less nuanced in tonality as if the music is more in a hurry to jump at you. The attack feel faster but definition less sharp, especially with sensitive IEM. With headphones or harder to drive IEM, the soundstage drastically expand, the bass became more articulate and punchy, but it’s still neutral and tends to add air between instruments. I use some amp that tends to make the sound dryer or thinner, which can give a false impression of extra clarity, the ATOM do not create this acoustic phenomenon, it injects naturalness to whole sound and to my ears, I hint of warmth that does not inflict on clean clarity. No grain, no distortion, no tonal imbalance, everything sound accurate and cohesive.

The DITA FEALTY sounds even airier at high gain, but less nuanced in lower mids or lower treble, as if the extra power inflicts on SPL (sound pressure level) and deliver a more vivid dynamic range that does not sound as flat as on low gain. For IEM, this can result in a slight tonal imbalance, which can easily be solved by using low gain.

Driving the HIFIMAN SUNDARA at a low gain isn’t suggested, and I consider these as very capricious Planar headphones to drive, to my ears, even the powerful Xduoo TA-10 that deliver 2W of output cannot deliver the full potential of these headphones. The ATOM do drive the SUNDARA at 99% of their full potential, which is extremely impressive, it has plenty of volumes to push it above listening level. Even at extremely high volume, the ATOM did not struggle to deliver stable current, so no distortion even if now the bass is wall-shaking and my neighbors can hear the music as if it was bookshelf speaker playing loud.

The TINHIFI P1 is hard to drive planar earphones and let me tell you I found the best pairing with the ATOM which delivers plenty of power at high gain. Now the sound isn’t dry, congested or overly intimate, the soundstage is wide and deep with an extremely clear background, which is impressive because with other sources it can sound hissy. Bass is still on the light side, but gain in natural extension, the kick is more weighty and present, but most of all is this exquisite mid-range that blossom fully offering among the best vocal in sub-500$ price range. With the Xduoo X20, mid-range feels flat and dry, now it has full presence with excellent separation and nice transparent layering. The ATOM resuscitates P1 sound. Incredibly addictive pairing for vocal-based music.

OVERALL SOUND is a natural neutral one with intimate transparent layering and smooth clarity. Timbre is full, slightly liquid in texture, with holographic definition and extra weight in tonal balance. Bass does gain in thickness but still have natural transition into mid-range, which is very lean and benefit from extra presence, treble isn’t unbalanced and extracts details smoothly. Stable and trustable, the ATOM act as a slightly warmed reference amp, level of clarity is a serious improvement over cheaper amping like the one find in DAP or even DAC-AMP. Whatever volume level, I never encounter distortion neither noisy noise floor.

 

PAIRING

The DITA FEALTY really pair beautifully with the ATOM, as a slightly bright and analytical IEM that can be aggressive with its upper mids and treble, this pairing tends to offer a more balanced and smooth sound, the bass gain body which is very welcome and add some fun energy to the sound. Mids are better separated and fuller in timbre, the vocal are less thin and less prompt to sibilance, gaining in naturalness and widen presentation. Treble too is more controled and balanced, slightly warmed and thickned. Soundstage and imaging is where the biggest improvement appears, having now a new hall like presentation with extra airiness.

The HIFIMAN SUNDARA will sound thin, dry and congested with weak amping, which isn’t the case at all with the ATOM. Soundstage expands drastically, going from close speakers to a small room with 4 speakers around you. The bass have more slam and the whole transient response feels faster. Timbre is more natural. Vocal are less recessed, and instrument separation more precisely layered. Treble is more relaxed and fuller in response as if lower and mid-treble was suddenly boosted.

The FINAL AUDIO E5000 is nothing less than a revelation with the ATOM, it goes from overly warm, bassy and intimate sound to highly articulated and balanced lush and transparent sound. The soundstage gain in both wideness and deepness, which offer a more spacious headroom. Clarity is seriously improved due to better bass control that extends better in sub region and has less boomy slam, resulting is less bass bleed. The mid-range is more accurate, especially in layering, but vocal gain presence too, which shows the true guilty pleasure of E5000 which is lush, thick smooth vocal. Treble extends further too, and gain in air separation, making upper highs more sparkly and micro details more generous. If you own the E5000, I urge you to make this small investment. Unlike the DITA FEALTY, the E5000 benefit from high gain, it opens the whole sound to the next level.

COMPARISONS

VS XDUOO XD-05Plus (260$)

The XD-05Plus sound notably different than ATOM, even if I use the same very Xduoo X20 DAC as an audio source. The first thing that hit is how more natural, smooth and balanced is the ATOM, which suggests it have cleaner sound too. The XD-05Plus sound slightly U shape compared to more neutral ATOM, bass tends to be more sub bassy and less thigh in the mid-bass attack, while the mids sound thinner and dryer, adding brightness or grain to some IEM, treble too sound more grainy. At high gain, I can encounter distortion or sound imbalance at high volume with the PLUS while it never happens with the ATOM. In terms of power, while the 2 deliver up to 1W @ 32ohm, I consider ATOM more stable and clean at high gain.

VS XDUOO TA-10 (300$)

The TA-10 is a hybrid tube amp that deliver 2 full Watt into 32ohm, it’s 2 times more power than the ATOM. This perhaps explain why I prefer driving the SUNDARA with this amp, as it tends to open the soundstage even more than ATOM and gently warm the sound without affecting transparency. SUNDARA sound more intimate with ATOM and go from small room to a big room with surround speakers using the TA-10. Tonality is warmer, timbre is thinner too, bass sound as well more transparent and textured , while the ATOM bass is injected with extra air, not grain. With IEM like warm sounding E5000, the TA-10 is less convincing and strangely affect imaging and tonal balance negatively, making me confirm the sound is less clear in the background and warmer in the definition. All in all, the only thing that TA-10 do better than ATOM is the level of power output, but to the cost of having higher harmonic distortion level, dirtier background floor and less balanced sound. As well, the volume control isn’t as precise as the ATOM, as if after a certain level (60-70), the volume step are way higher.

CONCLUSION

The JDS LABS ATOM is an excellent amplifier that delivers plenty of clean power, has a near-perfectly black noise floor and articulates a stable balanced sound.
In terms of quality of amplification, the ATOM can represent the perfect budget End Game amp for those looking to have a small, versatile and capable amping solution for both sensitive earphones and demanding headphones. Thanks to it’s well-done Gain modes, the ATOM will drive at full potential a wide array of iem, earbuds, and headphones.

At 100$, the ATOM is a real bargain that I highly recommend to anybody that needs a powerful desktop amp that does not take a lot of space and offer highly capable and versatile performance.