Both are desktop amplifiers, $375 against $370. 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 Geshelli Archel 3S Pro reaches 100 dB on 567 of the 567 models here, the Bottlehead Crack (OTL kit) on 565.
| Specification | Bottlehead Crack (OTL kit) | Geshelli Archel 3S Pro |
|---|---|---|
| Power into 32Ω | 271 mW | 1.0 W |
| Power into 150Ω | 403 mW | 213 mW |
| Power into 300Ω | 333 mW | 107 mW |
| Power into 600Ω | 227 mW | 53 mW |
| Output impedance | 120.0 Ω | not published |
| Output noise | not published | not published |
| Price | $375 | $370 |
| Headphones it reaches 100 dB on out of 567 | 565 | 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.
2 headphones reach 100 dB on the Geshelli Archel 3S Pro but not on the Bottlehead Crack (OTL kit) — Moondrop PARA, Symphonium Titan.
565 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: Bottlehead Crack (OTL kit) and Geshelli Archel 3S Pro. Or put either against your own headphones in the source comparison tool.