Both are desktop amplifiers, $99 against $129. 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 JDS Labs Atom Amp 2 reaches 100 dB on 567 of the 567 models here, the JDS Labs Atom+ (2nd gen) on 566.
| Specification | JDS Labs Atom+ (2nd gen) | JDS Labs Atom Amp 2 |
|---|---|---|
| Power into 32Ω | 1.0 W | 2.6 W |
| Power into 150Ω | 545 mW | 567 mW |
| Power into 300Ω | 272 mW | 284 mW |
| Power into 600Ω | 136 mW | 143 mW |
| Output impedance | 0.7 Ω | 0.7 Ω |
| Output noise | 1.99 µV | 1.33 µV |
| Price | $99 | $129 |
| 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.
1 headphone reaches 100 dB on the JDS Labs Atom Amp 2 but not on the JDS Labs Atom+ (2nd gen) — Symphonium Titan.
3 headphones stay below the audible-hiss threshold on the JDS Labs Atom Amp 2 but cross it on the JDS Labs Atom+ (2nd gen) (Campfire Audio Clara, Shure SE846, Vision Ears Phönix Final Edition).
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.
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 JDS Labs Atom Amp 2. Or put either against your own headphones in the source comparison tool.