Both are dongles, $269 against $299. 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?
On raw power they are level: each reaches 100 dB on 563 of the 567 non-electrostatic models here.
| Specification | Cayin RU7 | EarMen Colibri |
|---|---|---|
| Power into 32Ω | 160 mW | 75 mW |
| Power into 150Ω | 34 mW | 16 mW |
| Power into 300Ω | 17 mW | 8.0 mW |
| Power into 600Ω | 8.5 mW | 4.0 mW |
| Output impedance | not published | not published |
| Output noise | not published | not published |
| Price | $269 | $299 |
| Headphones it reaches 100 dB on out of 567 | 563 | 563 |
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 Cayin RU7 but not on the EarMen Colibri — HiFiMAN Susvara, Moondrop SKYLAND.
2 headphones reach 100 dB on the EarMen Colibri but not on the Cayin RU7 — Symphonium Crimson, Symphonium Helios.
561 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: Cayin RU7 and EarMen Colibri. Or put either against your own headphones in the source comparison tool.