Both are audio interfaces, $139 against $100. 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 Focusrite Scarlett Solo 4th gen reaches 100 dB on 552 of the 567 models here, the Zoom AMS-22 on 538.
| Specification | Focusrite Scarlett Solo 4th gen | Zoom AMS-22 |
|---|---|---|
| Power into 32Ω | 31 mW | 20 mW |
| Power into 150Ω | 19 mW | 6.5 mW |
| Power into 300Ω | 22 mW | 3.4 mW |
| Power into 600Ω | 11 mW | 1.8 mW |
| Output impedance | 50 Ω | 10 Ω |
| Output noise | not published | not published |
| Price | $139 | $100 |
| Headphones it reaches 100 dB on out of 567 | 552 | 538 |
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.
14 headphones reach 100 dB on the Focusrite Scarlett Solo 4th gen but not on the Zoom AMS-22 — Abyss AB-1266 Phi TC, Audeze LCD-5, Beyerdynamic DT 880 Edition (600Ω), 11 more.
51 headphones are left alone by the Zoom AMS-22 under the one-eighth rule but coloured by the Focusrite Scarlett Solo 4th gen (AKG K612 Pro, Audeze LCD-3, Audeze LCD-4, 48 more).
538 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 Solo 4th gen and Zoom AMS-22. Or put either against your own headphones in the source comparison tool.