Ferrum OOR


OOR will drive any headphones effortlessly to the max of their potential while preserving the essence of the music it amplifies

SKU: Ferrum OOR Categories: , , Tags: , , , , ,
Ferrum Audio Logo

Ferrum OOR

OOR, the only headphone amplifier with a soul

Ferrum OOR

OOR will redefine the category of headphone amplifiers. Ferrum OOR will drive any headphones effortlessly to the max of their potential, while preserving the essence of the music it amplifies.

Ultra low distortion, zero fatigue, huge dynamics and unrivaled detail result in ultimate enjoyment.

OOR actually makes something that is very difficult to accomplish, seem like the most natural thing on earth. The most important features are:

Truly Balanced

The signal path stays truly balanced using the XLR inputs and becomes truly balanced using the RCA inputs.

Ease of use

Only three knobs on the front panel to control the most important settings.

Ferrum Power Link

OOR performs very, very good right out of the box.

But OOR is made to excel above and beyond when used together with HYPSOS.

They use 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.

Superior control

Perfected steering of output transistors protect them and never let them turn off, therefore reducing distortion to inaudible levels and keeping them in a state where they can instantly unleash all their power, crucial for high dynamics, superlative control and authority in sound.

Enhanced transparency

The whole design is focussed on a balanced and very transparent sound signature, making listening fatigue something of the past.

Discrete design

The discrete power amp technology is developed in-house to achieve the best possible analog quality.

Look and behold the understated looks of OOR’s front, only to camouflage it’s intricate design laid bare on the rear. 100% analogue, 100% natural, 100% musical.

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 “Brand of Brothers”. OOR is their instrument of choice when they need to completely relax and prepare for their next assignment.

Marcin Hamerla Founder and CEO HEM

Unique output cable design: two wires delivering the power and two wires providing the feedback to ensure flat voltage at every moment.

They named this technique Ferrum Power Link (FPL) and it eliminates the harmful effects of the cable’s resistance effectively improving transient response.

The current delivery speed at the powered device’s input is significantly improved.

OOR comes with a carefully selected DC power adapter.

To get the most out of OOR you can connect it with HYPSOS using their proprietary Ferrum Power Link DC power cable.

Specifications Ferrum OOR

Specifications Ferrum OOR
  • Gain (dB): balanced -4 dB, + 6dB, +16 dB / single ended -10 dB, 0 dB, 10 dB
  • Operation: Fully balanced, proprietary discrete power amp technology
  • Inputs: XLR, RCA, 2.5 mm DC connector centre 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

Additional information


Hypsos Power Supply, OOR Headphone Amplifier, ORR & Hypsos


Ferrum Audio

Ferrum is their legacy When examining their roots, the new Ferrum team came to realise that the region where they all were born and worked for the latter part of their lives has a history of craftsmanship. One of those craftmanships was fuelled by the very large deposits of iron in the Warsaw area, which led to metallurgic specialism. Another very well known craftsman who made his undisputed imprint in classical music history is of course world famous composer and virtuoso pianist Frederic Chopin. Being born in ‘Żelazowa Wola’, 42 kilometres from their company headquarters, it seems the ability to work and study extremely hard is embedded in the region. Like Chopin, Ferrum is destined to bring its musical craftsmanship to the rest of the world. The funny fact that Żelazo means iron in Polish, and points to the inspiration for brand name Ferrum. Realising the father of parent company HEM’s CEO Marcin Hamerla was a blacksmith who forged iron most part of his working life, Marcin himself is nicknamed ‘the Hammer’ and HEME is a type of iron compound, the name Ferrum Audio comes as no surprise. All ingredients were right in front of them. A combination of craftsmanship and audio, firmly rooted in their own backyard, being the Warsaw region of Poland and Ferrum being the Latin word for iron. They just needed to look at their own region, remember their own family history, relate with nature, local industry and hard labour, to show their new-born to the rest of the world. Ferrum Audio is a result of a locally designed and manufactured audiophile grade audio electronics, which is the culmination of years worth of experience and knowledge. It is time to conquer the world. This is Ferrum’s heritage.
Ferrum Audio Logo

You may also like…