Both are dongles, $70 against $109. 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 Hidizs S9 Pro reaches 100 dB on 560 of the 567 models here, the DUNU DTC 480 on 554.
| Specification | DUNU DTC 480 | Hidizs S9 Pro |
|---|---|---|
| Power into 32Ω | 65 mW | 100 mW |
| Power into 150Ω | 14 mW | 21 mW |
| Power into 300Ω | 6.9 mW | 11 mW |
| Power into 600Ω | 3.5 mW | 5.3 mW |
| Output impedance | not published | 0.3 Ω unverified |
| Output noise | not published | 4 µV unverified |
| Price | $70 | $109 |
| Headphones it reaches 100 dB on out of 567 | 554 | 560 |
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.
6 headphones reach 100 dB on the Hidizs S9 Pro but not on the DUNU DTC 480 — HiFiMAN HE-6se V2, HiFiMAN HE6 Remastered, HiFiMAN Susvara, 3 more.
554 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: DUNU DTC 480 and Hidizs S9 Pro. Or put either against your own headphones in the source comparison tool.