Both are desktop amplifiers, $99 against $99. This page puts them side by side on the only three things a maker can be held to — power, output impedance and noise — and then asks the question that actually matters: which headphones do they treat differently?
The Schiit Magni Heresy reaches 100 dB on 567 of the 567 models here, the JDS Labs Atom+ (2nd gen) on 566.
| Specification | JDS Labs Atom+ (2nd gen) | Schiit Magni Heresy |
|---|---|---|
| Power into 32Ω | 1.0 W | 2.4 W |
| Power into 150Ω | 545 mW | 641 mW |
| Power into 300Ω | 272 mW | 410 mW |
| Power into 600Ω | 136 mW | 215 mW |
| Output impedance | 0.7 Ω | 0.25 Ω |
| Output noise | 1.99 µV | 1.5 µV unverified |
| Price | $99 | $99 |
| Headphones it reaches 100 dB on out of 567 | 566 | 567 |
A figure marked not published is missing from the maker’s own material, which is not the same as being good or bad. Where one of these two publishes a number and the other does not, the comparison on that axis cannot be made at all — and saying so is more useful than guessing.
| Load | JDS Labs Atom+ (2nd gen) | Schiit Magni Heresy |
|---|---|---|
| 32 Ω | Published | Published |
| 150 Ω | Published | Derived |
| 300 Ω | Derived | Published |
| 600 Ω | Published | Published |
Both makers publish a power rating, which is less common than the table above makes it look: of the 280 sources here, 209 publish a figure at at least one load and only 2 publish one at all four. JDS Labs Atom+ (2nd gen) publishes at 32 Ω, at 150 Ω and at 600 Ω; Schiit Magni Heresy at 32 Ω, at 300 Ω and at 600 Ω. Every other row is worked out from those — between two published loads, or beyond them holding voltage constant, which understates rather than flatters.
So the two columns are not equally firm row by row: at 150 Ω only the JDS Labs Atom+ (2nd gen) figure is the maker’s own and at 300 Ω only the Schiit Magni Heresy figure is the maker’s own. On those rows the derived number is the one to doubt first.
What each of these labels means, and why a derived figure is still worth printing, is set out in how this data was built.
1 headphone reaches 100 dB on the Schiit Magni Heresy but not on the JDS Labs Atom+ (2nd gen) — Symphonium Titan.
4 headphones are left alone by the Schiit Magni Heresy under the one-eighth rule but coloured by the JDS Labs Atom+ (2nd gen) (Campfire Audio Chimera, Moondrop Armature Art 12, Softears Volume, 1 more).
566 of the 567 models here reach 100 dB on both. That is a power count and nothing more; whether either source suits a given headphone also depends on the two lines above.
The counts above say how many models the two treat differently. This says by how much. The same 8 headphones appear on every page of this kind, ordered from the easiest to drive to the hardest, so a row can be read across pages as well as across columns. Headroom is at a 100 dB SPL peak.
The widest gap on the list is the Campfire Audio Andromeda 2020: Schiit Magni Heresy has +26 dB of headroom there against +18 dB. 7 dB is about 5.6 times the power, which matters for peaks rather than for how loud the music sits.
The hiss columns are empty for Schiit Magni Heresy because that maker publishes no output noise figure. That is a gap in the specification, not a quiet amplifier, and it is left blank here rather than filled with a plausible number.
| Headphone | Impedance | Needs | JDS Labs Atom+ (2nd gen) headroom | Schiit Magni Heresy headroom | JDS Labs Atom+ (2nd gen) hiss | Schiit Magni Heresy hiss |
|---|---|---|---|---|---|---|
| Shure SE846 | 9 Ω | 0.04 mW | +38 dB | +46 dB | 20 dB | not published |
| Campfire Audio Andromeda 2020 | 9 Ω | 4.0 mW | +18 dB | +26 dB | 0 dB | not published |
| Audeze LCD-2 Classic | 70 Ω | 0.79 mW | +29 dB | +32 dB | -1 dB | not published |
| Beyerdynamic DT 1990 Pro (250Ω) | 250 Ω | 0.63 mW | +27 dB | +29 dB | -6 dB | not published |
| HiFiMAN HE400se | 25 Ω | 7.9 mW | +20 dB | +25 dB | -7 dB | not published |
| Audio-Technica ATH-R70X | 470 Ω | 1.6 mW | +20 dB | +22 dB | -13 dB | not published |
| Sennheiser HD 600 | 300 Ω | 6.6 mW | +16 dB | +18 dB | -17 dB | not published |
| HiFiMAN Susvara | 60 Ω | 50 mW | +11 dB | +14 dB | -19 dB | not published |
These two cost the same, $99, so price settles nothing. Out of the 567 models here, the Schiit Magni Heresy drives one model to 100 dB and leaves 4 alone under the one-eighth rule — and on the other side there is no such advantage at all.
Everything in this paragraph counts only figures the two makers published. An advantage on an axis one of them leaves blank cannot be counted, and is not counted — how often that happens is its own page.
Each has a page of its own with every power figure traced to what the maker published and a full headphone list: JDS Labs Atom+ (2nd gen) and Schiit Magni Heresy. Or put either against your own headphones in the source comparison tool.