Both are desktop amplifiers, $2995 against $3200. 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 HeadAmp GS-X mk2 reaches 100 dB on 567 of the 567 models here, the SPL Phonitor x on 566.
| Specification | HeadAmp GS-X mk2 | SPL Phonitor x |
|---|---|---|
| Power into 32Ω | 7.1 W | 1.0 W |
| Power into 150Ω | 2.0 W | 3.1 W |
| Power into 300Ω | 1.0 W | 4.2 W |
| Power into 600Ω | 500 mW | 2.1 W |
| Output impedance | not published | 0.18 Ω |
| Output noise | not published | 5.48 µV |
| Price | $2995 | $3200 |
| 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 HeadAmp GS-X mk2 but not on the SPL Phonitor x — 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: HeadAmp GS-X mk2 and SPL Phonitor x. Or put either against your own headphones in the source comparison tool.