Both are desktop amplifiers, $1995 against $1700. 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 Wells Audio Milo reaches 100 dB on 567 of the 567 models here, the Ferrum OOR on 566.
| Specification | Ferrum OOR | Wells Audio Milo |
|---|---|---|
| Power into 32Ω | 1.1 W | 12.0 W |
| Power into 150Ω | 800 mW | 3.1 W |
| Power into 300Ω | 400 mW | 1.5 W |
| Power into 600Ω | 200 mW | 767 mW |
| Output impedance | 0.3 Ω | 0.1 Ω |
| Output noise | 1.5 µV unverified | 1.5 µV unverified |
| Price | $1995 | $1700 |
| 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 Wells Audio Milo but not on the Ferrum OOR — 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: Ferrum OOR and Wells Audio Milo. Or put either against your own headphones in the source comparison tool.