Both are portable amplifiers, $650 against $440. 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 FiiO Q15 reaches 100 dB on 567 of the 567 models here, the Chord Mojo 2 on 566.
| Specification | Chord Mojo 2 | FiiO Q15 |
|---|---|---|
| Power into 32Ω | 564 mW | 625 mW |
| Power into 150Ω | 145 mW | 149 mW |
| Power into 300Ω | 90 mW | 85 mW |
| Power into 600Ω | 45 mW | 43 mW |
| Output impedance | 0.06 Ω | 1.0 Ω |
| Output noise | 2.7 µV | 3.1 µV |
| Price | $650 | $440 |
| 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 FiiO Q15 but not on the Chord Mojo 2 — Symphonium Titan.
15 headphones are left alone by the Chord Mojo 2 under the one-eighth rule but coloured by the FiiO Q15 (64 Audio Nio, 64 Audio Volur, Campfire Audio Andromeda 2023, 12 more).
7 headphones stay below the audible-hiss threshold on the Chord Mojo 2 but cross it on the FiiO Q15 (AFUL Performer 8, Campfire Audio Chimera, Dunu SA6 MKII, 4 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.
Each has a page of its own with every power figure traced to what the maker published and a full headphone list: Chord Mojo 2 and FiiO Q15. Or put either against your own headphones in the source comparison tool.