Both are audio interfaces, $410 against $399. 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 Zoom UAC-232 reaches 100 dB on 563 of the 567 models here, the Focusrite Scarlett 16i16 (4th Gen) on 553.
| Specification | Focusrite Scarlett 16i16 (4th Gen) | Zoom UAC-232 |
|---|---|---|
| Power into 32Ω | 55 mW | 148 mW |
| Power into 150Ω | 27 mW | 51 mW |
| Power into 300Ω | 27 mW | 28 mW |
| Power into 600Ω | 14 mW | 14 mW |
| Output impedance | 11 Ω | 12 Ω |
| Output noise | not published | not published |
| Price | $410 | $399 |
| Headphones it reaches 100 dB on out of 567 | 553 | 563 |
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.
10 headphones reach 100 dB on the Zoom UAC-232 but not on the Focusrite Scarlett 16i16 (4th Gen) — HiFiMAN HE-6se V2, HiFiMAN HE6 Remastered, HiFiMAN Susvara, 7 more.
553 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: Focusrite Scarlett 16i16 (4th Gen) and Zoom UAC-232. Or put either against your own headphones in the source comparison tool.