Both are desktop amplifiers, $129 against $150. 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 PreSonus HP4 on 558.
| Specification | JDS Labs Atom Amp 2 | PreSonus HP4 |
|---|---|---|
| Power into 32Ω | 2.6 W | 69 mW |
| Power into 150Ω | 567 mW | 52 mW |
| Power into 300Ω | 284 mW | 26 mW |
| Power into 600Ω | 143 mW | 13 mW |
| Output impedance | 0.7 Ω | not published |
| Output noise | 1.33 µV | not published |
| Price | $129 | $150 |
| Headphones it reaches 100 dB on out of 567 | 567 | 558 |
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.
9 headphones reach 100 dB on the JDS Labs Atom Amp 2 but not on the PreSonus HP4 — Moondrop COSMO, Moondrop PARA, Moondrop PARA 2, 6 more.
558 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 Amp 2 and PreSonus HP4. Or put either against your own headphones in the source comparison tool.