JDS Labs Atom Amp 2: power output and what it will drive

The JDS Labs Atom Amp 2 is a desktop amplifier at $129. It delivers 2.6 W into 32Ω and 284 mW into 300Ω, which ranks it 32 of 280 for raw power among the sources in this database.

Measured at 100 dB SPL it has comfortable headroom on 565 of the 567 dynamic and planar headphones catalogued here and enough but not generous on 2. Rated at maximum continuous power rather than a brief burst, so its numbers are stricter than most. The 4.4 mm jack is single-ended.

Specifications

What it actually puts out

TypeDesktop amplifier

Price$129

Power into 32 Ω2.6 W

Power into 150 Ω567 mW

Power into 300 Ω284 mW

Power into 600 Ω143 mW

Output impedance0.7 Ω

Output noise1.33 µV

Comfortable headroom on 565 of 567 headphones (100%)

Provenance

Where these numbers come from

The manufacturer publishes 2.6 W into 32Ω, 143 mW into 600Ω. The rest of the table is worked out from those.

Derived rows hold output voltage steady, as an amplifier does (method).

Source: jdslabs.com, blog.jdslabs.com.

Load	Power	Status	How it was arrived at
32 Ω	2.6 W	Published	the manufacturer publishes this figure at this exact load
150 Ω	567 mW	Derived	worked out between two published loads, holding output voltage linear between them
300 Ω	284 mW	Derived	worked out between two published loads, holding output voltage linear between them
600 Ω	143 mW	Published	the manufacturer publishes this figure at this exact load

Matching

Against 40 well-known headphones

Easiest to hardest to drive, with headroom at a 100 dB SPL peak.

Headphone	Impedance	Sensitivity	Needs	Headroom	Verdict
Shure SE846	9 Ω	114.0 dB/mW	0.04 mW	+43 dB	Comfortable audible hiss
64 Audio U12t	12.6 Ω	108.0 dB/mW	0.16 mW	+38 dB	Comfortable faint hiss
Shure SE215	17 Ω	107.0 dB/mW	0.20 mW	+38 dB	Comfortable faint hiss
Moondrop Aria	32 Ω	107.1 dB/mW	0.19 mW	+41 dB	Comfortable faint hiss
Audeze LCD-X 2021	20 Ω	103.0 dB/mW	0.50 mW	+35 dB	Comfortable faint hiss
Truthear Hexa	20.5 Ω	103.1 dB/mW	0.49 mW	+35 dB	Comfortable faint hiss
Sennheiser IE 200	18 Ω	101.6 dB/mW	0.69 mW	+33 dB	Comfortable faint hiss
Sony MDR-7506	63 Ω	106.0 dB/mW	0.25 mW	+37 dB	Comfortable faint hiss
Meze 99 Classics	32 Ω	103.0 dB/mW	0.50 mW	+37 dB	Comfortable faint hiss
Focal Clear MG	55 Ω	104.0 dB/mW	0.40 mW	+36 dB	Comfortable
Philips SHP9500	32 Ω	101.0 dB	0.79 mW	+35 dB	Comfortable
Focal Utopia	80 Ω	104.0 dB/mW	0.40 mW	+34 dB	Comfortable
Meze Empyrean	32 Ω	100.0 dB	1.0 mW	+34 dB	Comfortable
Campfire Audio Andromeda 2020	9 Ω	94.0 dB	4.0 mW	+23 dB	Comfortable
Etymotic ER2SE	15 Ω	96.0 dB/mW	2.5 mW	+27 dB	Comfortable
AKG K371	32 Ω	99.1 dB/mW	1.2 mW	+33 dB	Comfortable
Audio-Technica ATH-M50X	38 Ω	99.0 dB/mW	1.3 mW	+32 dB	Comfortable
Beyerdynamic DT 900 Pro X	48 Ω	100.0 dB/mW	1.0 mW	+32 dB	Comfortable
Audeze LCD-2 Classic	70 Ω	101.0 dB/mW	0.79 mW	+32 dB	Comfortable
Grado SR80x	38 Ω	98.0 dB/mW	1.6 mW	+31 dB	Comfortable
Sennheiser HD 560S	120 Ω	100.8 dB/mW	0.83 mW	+29 dB	Comfortable
HiFiMAN Edition XS	18 Ω	92.0 dB	6.3 mW	+24 dB	Comfortable
HiFiMAN Arya Stealth	32 Ω	94.0 dB	4.0 mW	+28 dB	Comfortable
Dan Clark Audio AEON 2 Closed	13 Ω	90.0 dB/mW	10 mW	+20 dB	Comfortable
Audeze LCD-5	14 Ω	90.0 dB/mW	10 mW	+21 dB	Comfortable
Beyerdynamic DT 1990 Pro (250Ω)	250 Ω	102.0 dB/mW	0.63 mW	+27 dB	Comfortable
HiFiMAN HE400se	25 Ω	91.0 dB	7.9 mW	+24 dB	Comfortable
HiFiMAN Sundara	32 Ω	92.0 dB	6.3 mW	+26 dB	Comfortable
Dan Clark Audio Stealth	23 Ω	90.0 dB/mW	10 mW	+23 dB	Comfortable
Fostex T50RP MK3	50 Ω	92.0 dB/mW	6.3 mW	+24 dB	Comfortable
AKG K702	62 Ω	92.9 dB/mW	5.1 mW	+24 dB	Comfortable
ZMF Verite Closed	300 Ω	99.0 dB/mW	1.3 mW	+24 dB	Comfortable
Sennheiser HD 650	300 Ω	97.8 dB/mW	1.7 mW	+22 dB	Comfortable
Sennheiser HD 800S	300 Ω	96.8 dB/mW	2.1 mW	+21 dB	Comfortable
Beyerdynamic DT 770 Pro (250Ω)	250 Ω	96.0 dB	2.5 mW	+21 dB	Comfortable
Audio-Technica ATH-R70X	470 Ω	98.0 dB/mW	1.6 mW	+21 dB	Comfortable
ZMF Atrium	300 Ω	96.0 dB/mW	2.5 mW	+21 dB	Comfortable
Abyss AB-1266 Phi TC	50 Ω	88.0 dB/mW	16 mW	+20 dB	Comfortable
Sennheiser HD 600	300 Ω	91.8 dB/mW	6.6 mW	+16 dB	Comfortable
HiFiMAN Susvara	60 Ω	83.0 dB	50 mW	+15 dB	Comfortable

Noise

Will it hiss?

At 1.33 µV of output noise, here is where that noise lands in the five most revealing in-ears in the database.

This one hisses. With the most sensitive in-ears in the database its own noise lands around 23 dB SPL, which you will hear between tracks and in quiet passages.

In-ear	Impedance	Sensitivity	Hiss level
Simgot EA500	16 Ω	141.0 dB/V	23 dB SPL
Tanchjim EA FORCE	17 Ω	137.7 dB/V	20 dB SPL
Shure SE846	9 Ω	134.5 dB/V	17 dB SPL
Campfire Audio Clara	13.3 Ω	134.1 dB/V	17 dB SPL
64 Audio Fourte	10 Ω	134.0 dB/V	16 dB SPL

Damping

Output impedance and the one-eighth rule

At 0.7Ω output impedance, the one-eighth rule says this source suits headphones of 5.6Ω and above. 4 of the 567 models here fall below that. Most of them are multi-driver in-ears, and the mismatch tilts the frequency response audibly rather than subtly.

Check any pair.

Cheaper

The cheapest thing here that does the same job

Source	Type	Price	Into 300 Ω	Output impedance	Output noise
Schiit Magni Unity	desktop amplifier	$119	415 mW	0.1 Ω	1.59 µV

Of the 280 sources here, 1 do everything the JDS Labs Atom Amp 2 does as a headphone output: reach 100 dB on every headphone it reaches, stay inside the one-eighth rule wherever it does and stay under the audible-hiss threshold wherever it does. The cheapest of them is the Schiit Magni Unity at $119, against this one’s $129 — $10 less.

This counts the headphone output only; inputs, converters, the volume control and the build are outside it.

Alternatives

Compared with its closest rivals: vs ART HeadAmp 4 Pro · vs JDS Labs Atom+ (2nd gen) · vs Little Dot MK II · vs PreSonus HP4 · vs Schiit Magni Unity · vs Schiit Vali 2+.

Compare any two or match your own headphones. Every JDS Labs source here.

JDS Labs Atom Amp 2: power output and what it will drive

What it actually puts out

Where these numbers come from

Against 40 well-known headphones

Will it hiss?

Output impedance and the one-eighth rule

The cheapest thing here that does the same job

Other desktop amplifiers at a similar price

ART HeadAmp 4 Pro

Schiit Magni Unity

Schiit Magni+

Topping L30 II

Schiit Vali 2+

Schiit Vali 3