Both are desktop DAC/amps, $199 against $219. 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 SMSL C200 reaches 100 dB on 567 of the 567 models here, the Fosi Audio K7 on 566.
| Specification | Fosi Audio K7 | SMSL C200 |
|---|---|---|
| Power into 32Ω | 600 mW | 1.3 W |
| Power into 150Ω | 128 mW | 277 mW |
| Power into 300Ω | 64 mW | 139 mW |
| Power into 600Ω | 32 mW | 69 mW |
| Output impedance | not published | not published |
| Output noise | 2.5 µV | not published |
| Price | $199 | $219 |
| Headphones it reaches 100 dB on out of 567 | 566 | 567 |
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.
1 headphone reaches 100 dB on the SMSL C200 but not on the Fosi Audio K7 — Symphonium Titan.
566 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: Fosi Audio K7 and SMSL C200. Or put either against your own headphones in the source comparison tool.