Ferrum OOR- fully balanced headphone amplifier
Ferrum OOR- fully balanced headphone amplifier
Ferrum OOR- fully balanced headphone amplifier
Ferrum OOR- fully balanced headphone amplifier
Ferrum OOR- fully balanced headphone amplifier
Ferrum OOR- fully balanced headphone amplifier
Ferrum OOR- fully balanced headphone amplifier
Ferrum OOR- fully balanced headphone amplifier
Ferrum OOR- fully balanced headphone amplifier

Ferrum OOR- fully balanced headphone amplifier

CHF 1,949.00

1 piece in stock and available for immediate delivery.

Test products at home - free of charge and for up to a week


OOR, the only headphone amplifier with a soul

OOR will redefine the headphone amplifier category. The OOR effortlessly pushes any headphone to the maximum of its potential while preserving the essence of the music it amplifies. Extremely low distortion, no fatigue, enormous dynamics and unmatched detail ensure ultimate listening pleasure. OOR makes something that is actually very difficult to achieve seem like the most natural thing in the world.

"OOR is made by a group of very talented engineers and industrial designers right in the heart of Poland. They like to refer to Ferrum as the "Brand of Brothers". OOR is their instrument of choice when they are completely relaxing and looking forward to their next Want to prepare the order."

Marcin Hamerla, founder and CEO HEM



"Following the EISA Award-winning Hypsos programmable power supply unit, Ferrum has focused its expertise on designing a purely analogue headphone amplifier. The OOR (Dutch for 'ear') offers a deep and wide response, and enough power to drive even the most challenging of high-end headphones – whatever model you use, balanced or unbalanced, appears to have been given a shot of extra power. This superior performance is complemented by a compact, desktop-friendly design that emphasizes ease of use use, and is a cosmetic match for Ferrum's Hypsos PSU, which can of course be employed by way of upgrade. Balanced and single-ended inputs and headphone outs cater to every listening scenario."

Ferrum Audio OOR | EISA – Expert Imaging and Sound Association


Ferrum OOR

"First-class headphone amplifier with preamplifier function. Fully symmetrical design, high-quality components inside and out, the customer only has to do without a remote control. First-class engineering from the HEM team, which has also developed Mytek products. Thanks to high performance at every impedance for All dynamic and magnetostatic headphones are suitable."


Headfonics Audio Reviews

"The Ferrum OOR on its own is a very good solid-state analog headphone amplifier and preamp. However, paired with the HYPSOS PSU it becomes a great amplifier."

Ferrum OOR review

Ferrum OOR Headphone Amplifier Review - Headfonics



 Headfonia Reviews - Quality audio reviews

"The OOR is an addictive amplifier with a high technical level and all the power you'll ever need. Ferrum has managed to make the OOR sound precise yet musical and that's exactly what they were going for.

The Ferrum Audio OOR has an excellent price/performance ratio even though it sets you back €2K, or even €3K with the supplementary Hypsos PSU."

Ferrum Audio OOR Review - Headfonia Reviews



majorhifi award banner gold XL

"This amp combo is one of the best pieces of gear you can buy period. Not only is it a powerful system with plenty of features, but its reference style sound output is in a league of its own, offering some of the purest detail that I've heard recently. Even though it's quite a pricey product, the OOR and Hypsos are the perfect endgame amplifier for those looking for a professional system."

Ferrum OOR With Hypsos Power System Review - Major HiFi



"Right here, right now, the Ferrum Audio duo is one of those products you listen to and think, will this change everything? It's that surprising, and that much fun. Reviewer's Choice. OUT OF THIS WORLD. "

Ferrum Audio OOR and HYPSOS Headphone Amplifier | REVIEW - Part-Time Audiophile



The most important features

Truly symmetrical
The signal path remains truly symmetrical via the XLR inputs and becomes truly symmetrical via the RCA inputs.

Easy to use
Only three controls on the front to control the most important settings.

Ferrum Power Link
OOR delivers immediately After unpacking, a very, very good performance. But OOR can do even more when used together with HYPSOS. We use our Ferrum Power Link (FPL for short) to connect the two. HYPSOS then reaches its maximum performance and, in combination with OOR, unleashes unheard musicality.

Superior control
The perfected control of the output transistors protects them and never allows them to turn off, eliminating distortion on a Inaudible levels can be reduced and they are kept in a state in which they can immediately develop their full power, which is crucial for high dynamics, superior control and authority in the sound.

Improved transparency
The entire design is aimed at a balanced and very transparent sound signature, so that listening fatigue is a thing of the past.

Discrete construction
The discrete power amplifier technology was developed internally to to achieve the best possible analogue quality.

Check out the simple design of the front of the OOR, which only hides its intricate design on the back. 100% analogue, 100% natural, 100% musical.

Fully symmetrical from A to Z, even directly after the RCA inputs, to get the most out of each headphone. The brightness of the logo on the front of the OOR can be dimmed to protect the eyes. Ferrum Power Link for the ultimate connection with HYPSOS.

Combine OOR with HYPSOS to unleash unheard musicality. Together they will excel.
Look and admire the understated look of OOR's front, which only hides the intricate design on the back. 100% analog, 100% natural, 100% musical.



  • Gain (dB): balanced -4 dB, + 6dB, +16 dB / single ended -10 dB, 0 dB, 10dB
  • Operation: Fully balanced, proprietary discrete power amp technology
  • Inputs: XLR, RCA, 2.5 mm DC connector center positive, proprietary 4-pin DC connector
  • Outputs: Balanced 4-pin XLR, 6.35 mm jack
  • Frequency Response:  20 Hz – 100 kHz 0.1 dB
  • 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
  • THD + Noise: TBA
  • Input Impedance: 94 kΩ
  • Output Impedance Single Ended: 22 Ω on pre-amp
  • Output Impedance Balanced: 44 Ω on pre-amp
  • Output headphones Impedance: < 0.3 Ω
  • Power Consumption: Idle <15 W
  • Power Adapter: 100/240 V AC to 22-30 V DC
  • Dimension (W x D x H) (In/cm): 8.6 x 8.1 x 2.0 inch / 21.7 x 20.6 x 5 cm
  • Weight (kg/lbs): 1.8 kg / 3.97 LBS