Ferrum OOR | Desktop Headphone Amplifier

Ferrum's OOR Headphone Amp is a Ground-Up Design Without Precedent, Created From Exploration of Analog Audio in its Purest Form
- Truly Balanced Design
- Superior Control, Reducing Distortion to Inaudible Levels
- In-house Discrete Power Amp Technology
- Balanced and Transparent Sound Signature
- Comes with DC Power Adapter

Pure Amplification
Following the success of the HYPSOS Hybrid Power System, which earned an EISA Award in 2021, Ferrum continued to push the boundaries of what dedicated audio components could achieve. The result was OOR, a ground-up headphone amplifier design that went on to receive the EISA Award for Best Headphone Amplifier in 2022–2023. Built around a philosophy of pure analog performance, OOR combines understated aesthetics with sophisticated amplifier technology to deliver an exceptionally clean and dynamic listening experience.
Designed to drive a wide range of headphones to their full potential, OOR pairs ultra-low distortion with expansive dynamics and remarkable detail. Its transparent presentation preserves the character of your music, allowing everything from subtle nuances to powerful musical passages to come through with clarity and control.
For listeners looking to take their system even further, OOR is designed to pair seamlessly with Ferrum’s HYPSOS Hybrid Power System. Together, they offer an opportunity to explore even greater performance, making OOR a compelling centerpiece for a high-end headphone setup.
Ferrum Power Link (FPL)
OOR performs very, very good right out of the box. But OOR is made to excel above and beyond when used together with HYPSOS. Ferrum uses what they dubbed their Ferrum Power Link (FPL in short) to connect the two. HYPSOS then will perform to its maximum, unleashing unheard musicality from the combination with OOR.
| Device Features | |
|---|---|
Headphone Amp |
Yes |
Analog Audio Outputs |
Balanced 4-pin XLR, 6.35 mm jack
|
Analog Audio Inputs |
XLR, RCA, 2.5 mm DC connector center positive, proprietary 4-pin DC connector
|
SNR/THD |
THD on balanced output: 0.00011% / -119 dB, 1 mW into 50 Ω; 0.00028% / -111 dB, 100 mW into 50 Ω
THD on unbalanced output: 0.00008% / -122 dB, 1 mW into 50 Ω; 0.00028% / -111 dB, 100 mW into 50 Ω |
Device Weight |
3.97lbs
|
Dimensions |
8.6 x 8.1 x 2.0"
|
Full Specifications |
|
| Amplifier | |
Output Power |
Output Power Single Ended: 400 mW into 300 Ω, 2 W into 60 Ω
Output Power Balanced: 1.600 mW into 300 Ω, 8 W into 60 Ω |
