atelier 13 audio
FERRUM OOR
HEADPHONE AMPLIFIER
All it takes is a revolution
You can make a first impression only once. With this idea in mind, parent company HEM set out to conquer the world with Ferrum. A new brand, which they modelled on their twenty years’ worth of experience in designing and manufacturing audio electronics. They decided to start at the beginning of any hifi system; the power supply. And make it better. In quick succession, they then added a Headphone Amplifier to the Ferrum family ...
Enter Ferrum’s second born
With the OOR our aim is to redefine the category of headphone amplifiers. 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. You’ll just love it!
Look and behold the understated looks of the front of the OOR
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
... only to camouflage it's intricate design laid bare on the rear.
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100% Analogue
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100% Natural
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100% Musical
FEATURES
OOR will redefine the category of headphone amplifiers. 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:
Ferrum Power Link
The OOR performs very, very well right out of the box. But OOR is made to excel above and beyond when used together with HYPSOS. We use what we dubbed our 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.
Truly Balanced
The signal path stays truly balanced using the XLR inputs and becomes truly balanced using the RCA inputs.
Enhanced Transparency
The whole design is focussed on a balanced and very transparent sound signature, making listening fatigue something of the past.
Ease of Use
Only three knobs on the front panel to control the most important settings.
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.
Discrete Design
The discrete power amp technology is developed in-house to achieve the best possible analog quality.
Standalone Preamplifier
Enhanced system functionality with analog balanced XLR and single ended RCA Inputs and Outputs. Alps Volume Control.
The Hypsos is Ferrum’s successful PSU and the OOR can be upgraded with this PSU. By using the Ferrum Power Link (FPL) connection, it can perform its 4TSD measurements far deeper inside OOR than it can with any other product.
DC Power Supply
OOR comes with a carefully selected DC power adapter. To get the most out of OOR you can connect it with the Ferrum HYPSOS LPSU using our proprietary Ferrum Power Link DC power cable. This FPL cable can be ordered separately.
Unique FPL cable design
Two wires delivering the power and two wires providing the feedback to ensure flat voltage at every moment. We 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.
Specifications
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
Preamp : 1 x XLR, 1 x RCA
Power : 2.5 mm DC connector centre positive, proprietary 4-pin DC connector
Outputs
HP : Balanced 4-pin XLR, 6.35 mm jack
Preamp : 1 x XLR, 1 x RCA
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
Balanced : 44 Ω on pre-amp
Headphones : < 0.3 Ω
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
OOR comes with a carefully selected DC power adapter.
To get the most out of OOR you can connect it with HYPSOS using our proprietary Ferrum Power Link DC power cable. This FPL cable can be ordered separately.
OOR Ferrum FPL Cable
0.5m - $99
What they say ...
"... Ever since the Ferrum Audio OOR arrived at the HFN headquarters I have been using it nonstop, together with the Hypsos power supply. 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.. “
Lieven - Headfonia August 19, 2021
... more of what they say ...
" ... 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. It’s not cheap but for a high end unit, it’s actually fairly affordable and it easily plays along with even more expensive amplifiers. If you have this kind of budget available and you like this type of neutral and technically strong tuning, I wouldn’t hesitate to order the Hypsos PSU with it."
Lieven - Headfonia August 19, 2021
SOUND
The OOR with selected High End Headphones
Hifiman HE6SE
A really great combo. The OOR has more than enough power for these cans and they really make the HE6SE shine. Great detail, great speed, excellent layer and a natural amount of body is what you get here. The OOR and HE6SE combo is technically strong and musical at the same time. What I like most here is the bass delivery and layering, as well as the vocals and treble presentation. This combo has great synergy and it’s fully recommended.
Meze Audio Empyrean
The Empyrean is a very full sounding headphone that carries a full body from top to bottom. It has bigger bass and a good amount of warmth and smoothness in the delivery. If you like the Empyrean, it’s probably because of this specific tuning.
I for one love the Empyrean but I can’t deny that it sometimes is a bit too much in regards to body/bass and it can be overwhelming at times. What the OOR does here is tame the Empyrean in this regard. You get a lighter sounding Empyrean in regards to bass and body and the neutral tuning of the OOR takes away a bit of the Empyrean’s warmth. I have to say that I like both versions of the Empyrean’s sound but for those who like its tuning, but find it a bit heavy and warm, this amplifier could be the perfect solution for this magnificent headphone.
Rosson RAD-0
Another headphone I have really enjoyed listening to with the OOR is the Rosson RAD-0. I really like the tuning of the RAD-0 but like so many, I just wish it was a bit lighter and more comfortable. The synergy with the OOR is really nice and you get a tight, and fast sound, with a natural amount of body and excellent speed. The bass and vocals here are really impressive as well as the layering in the bass and mids. IT’s a very musical combo and the OOR is in perfect control at all times. This for me might well be one of the best amplifiers for the RAD-0 which I have ever had the pleasure to listen to.
Lieven - Headfonia August 19, 2021
