Both are dongles, $70 against $99. 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 HiBy FC4 reaches 100 dB on 561 of the 567 models here, the DUNU DTC 480 on 554.
| Specification | DUNU DTC 480 | HiBy FC4 |
|---|---|---|
| Power into 32Ω | 65 mW | 110 mW |
| Power into 150Ω | 14 mW | 23 mW |
| Power into 300Ω | 6.9 mW | 12 mW |
| Power into 600Ω | 3.5 mW | 5.9 mW |
| Output impedance | not published | not published |
| Output noise | not published | 1.7 µV |
| Price | $70 | $99 |
| Headphones it reaches 100 dB on out of 567 | 554 | 561 |
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.
| Load | DUNU DTC 480 | HiBy FC4 |
|---|---|---|
| 32 Ω | Published | Published |
| 150 Ω | Derived | Derived |
| 300 Ω | Derived | Derived |
| 600 Ω | Derived | Derived |
Both makers publish a power rating, which is less common than the table above makes it look: of the 280 sources here, 209 publish a figure at at least one load and only 2 publish one at all four. DUNU DTC 480 publishes at 32 Ω; HiBy FC4 at 32 Ω. Every other row is worked out from those — between two published loads, or beyond them holding voltage constant, which understates rather than flatters.
The two publish at the same loads, which is the one case where the rows of this table can be read straight across.
What each of these labels means, and why a derived figure is still worth printing, is set out in how this data was built.
7 headphones reach 100 dB on the HiBy FC4 but not on the DUNU DTC 480 — HiFiMAN HE-6se V2, HiFiMAN HE6 Remastered, HiFiMAN Susvara, 4 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.
The counts above say how many models the two treat differently. This says by how much. The same 8 headphones appear on every page of this kind, ordered from the easiest to drive to the hardest, so a row can be read across pages as well as across columns. Headroom is at a 100 dB SPL peak.
The widest gap on the list is the Sennheiser HD 600: HiBy FC4 has +2 dB of headroom there against +0 dB. 2 dB is about 1.7 times the power, which matters for peaks rather than for how loud the music sits.
The hiss columns are empty for DUNU DTC 480 because that maker publishes no output noise figure. That is a gap in the specification, not a quiet amplifier, and it is left blank here rather than filled with a plausible number.
| Headphone | Impedance | Needs | DUNU DTC 480 headroom | HiBy FC4 headroom | DUNU DTC 480 hiss | HiBy FC4 hiss |
|---|---|---|---|---|---|---|
| Shure SE846 | 9 Ω | 0.04 mW | +27 dB | +29 dB | not published | 19 dB |
| Campfire Audio Andromeda 2020 | 9 Ω | 4.0 mW | +7 dB | +9 dB | not published | -1 dB |
| Audeze LCD-2 Classic | 70 Ω | 0.79 mW | +16 dB | +18 dB | not published | -3 dB |
| Beyerdynamic DT 1990 Pro (250Ω) | 250 Ω | 0.63 mW | +11 dB | +13 dB | not published | -7 dB |
| HiFiMAN HE400se | 25 Ω | 7.9 mW | +8 dB | +10 dB | not published | -8 dB |
| Audio-Technica ATH-R70X | 470 Ω | 1.6 mW | +4 dB | +7 dB | not published | -14 dB |
| Sennheiser HD 600 | 300 Ω | 6.6 mW | +0 dB | +2 dB | not published | -18 dB |
| HiFiMAN Susvara | 60 Ω | 50 mW | -2 dB | +1 dB | not published | -20 dB |
The HiBy FC4 costs $29 more than the DUNU DTC 480. Out of the 567 models here, that difference buys 7 more models driven to 100 dB.
Nothing runs the other way: there is no axis here on which the cheaper of the two does better.
Everything in this paragraph counts only figures the two makers published. An advantage on an axis one of them leaves blank cannot be counted, and is not counted — how often that happens is its own page.
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 HiBy FC4. Or put either against your own headphones in the source comparison tool.