Both are desktop amplifiers, $539 against $600. 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 H400 MK2 reaches 100 dB on 567 of the 567 models here, the Soncoz SGA1 on 566.
| Specification | SMSL H400 MK2 | Soncoz SGA1 |
|---|---|---|
| Power into 32Ω | 2.5 W | 407 mW |
| Power into 150Ω | 527 mW | 207 mW |
| Power into 300Ω | 260 mW | 210 mW |
| Power into 600Ω | 130 mW | 105 mW |
| Output impedance | <0.1 Ω | 0.1 Ω |
| Output noise | not published | 1.8 µV |
| Price | $539 | $600 |
| Headphones it reaches 100 dB on out of 567 | 567 | 566 |
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 H400 MK2 but not on the Soncoz SGA1 — 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: SMSL H400 MK2 and Soncoz SGA1. Or put either against your own headphones in the source comparison tool.