Both are dongles, $259 against $200. 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 THX Onyx reaches 100 dB on 565 of the 567 models here, the Shanling UA5 on 562.
| Specification | Shanling UA5 | THX Onyx |
|---|---|---|
| Power into 32Ω | 137 mW | 124 mW |
| Power into 150Ω | 29 mW | 26 mW |
| Power into 300Ω | 15 mW | 13 mW |
| Power into 600Ω | 7.3 mW | 6.6 mW |
| Output impedance | 0.8 Ω | 0.2 Ω |
| Output noise | 3.5 µV unverified | not published |
| Price | $259 | $200 |
| Headphones it reaches 100 dB on out of 567 | 562 | 565 |
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.
3 headphones reach 100 dB on the THX Onyx but not on the Shanling UA5 — Moondrop COSMO, Symphonium Crimson, Symphonium Helios.
12 headphones are left alone by the THX Onyx under the one-eighth rule but coloured by the Shanling UA5 (64 Audio Nio, 64 Audio Volur, Campfire Audio Andromeda 2023, 9 more).
562 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: Shanling UA5 and THX Onyx. Or put either against your own headphones in the source comparison tool.