Ferrum Audio OOR Analogue Headphone Amplifier

Ferrum Audio OOR Fully Balanced Headphone Amplifier / Preamp

Overview

The Ferrum Audio OOR Balanced Headphone Amplifier is a fully analogue, fully balanced amplifier designed to extract the purest performance from any headphone. Handcrafted in Poland, it represents Ferrum Audio’s pursuit of uncompromising sound — combining ultra-low distortion, immense dynamics, and natural musicality in one elegant desktop design.

OOR is built from the ground up around a discrete analogue topology. Every stage of the circuit has been engineered for transparency and drive. The amplifier operates in fully balanced mode, converting even single-ended RCA inputs into balanced internally for optimal signal integrity. This design ensures an exceptionally low noise floor, wide dynamic range, and precise stereo imaging.

Power delivery is generous. The OOR outputs up to 8 watts into 60 ohms from its balanced 4-pin XLR connection, and around 2 watts into 60 ohms from its 6.35 mm single-ended output. This makes it capable of driving a wide range of headphones — from high-impedance studio models to power-hungry planar magnetics — with authority and control. The result is effortless performance and lifelike realism across every genre of music.

The OOR’s sound signature is clear, balanced, and fatigue-free. It delivers the immediacy and presence of live sound while maintaining natural tonal character. Bass notes are tight and textured, the midrange is open and expressive, and treble is extended without harshness. Its musical neutrality makes it ideal for critical listening, studio use, or home reference setups.

Connectivity is straightforward yet comprehensive. The OOR provides balanced XLR and unbalanced RCA inputs, along with a balanced 4-pin XLR headphone output and a 6.35 mm jack for conventional connections. A pre-amp output allows integration into a wider two-channel system or powered speakers. The front panel offers three simple controls — input select, gain, and volume — for intuitive operation during listening sessions.

For those seeking ultimate performance, the OOR is designed to pair perfectly with the Ferrum HYPSOS Hybrid Power Supply. Using Ferrum’s Power Link (FPL) connection, HYPSOS optimises voltage regulation and current delivery, unlocking even greater dynamics, control, and micro-detail. The two components share matching dimensions and styling, forming a compact, high-end audio stack that fits seamlessly into any desktop or studio environment.

In daily use, the Ferrum Audio OOR impresses with its speed, transparency, and musical engagement. Whether you’re mastering a track, evaluating headphones, or simply enjoying your favourite albums, OOR brings you closer to the recording with remarkable precision. Its minimalist chassis, solid build quality, and balanced architecture reflect Ferrum’s commitment to lasting performance and refined European design.

For Groove Central customers seeking a reference-level balanced headphone amplifier, the Ferrum Audio OOR delivers unmatched realism, drive, and listenability. When paired with the HYPSOS power supply, it becomes one of the most capable headphone amplification systems available — revealing the emotion and energy behind every note.

OOR, the only headphone amplifier with a soul and a second EISA award!

 

Key Features

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

• Ease of Use with only three knobs on the front panel to control the most important settings. 

• Superior internal circuitry and output transistor control design for reducing distortion to inaudible levels and instantly unleash all their power when needed for high dynamics, superlative control and authority in sound.

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

• The OOR's discrete power amp technology is developed in-house to achieve the best possible analogue quality.

• With the "Ferrum Power Link", the OOR can be made to excel even further when used with the HYPSOS power supply.

Technical Stuff 

Ferrum Audio OOR Headphone Amp / Preamp Video Summary ...

A Look Inside Ferrum Audio OOR Headphone Amp / Preamp ...

For More Information

Visit the manufacturer's website.

Returns Policy

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Should you wish to return your order, please notify us within 14 days of purchase with a valid reason for return. If we are unable to resolve your complaint or further assist you, we will process a refund upon timely receipt of the goods purchased. Unopened goods will be refunded in full. Refunds will be processed promptly and payment made by the same method that you made payment. All refunds are made at the discretion of groovecentral.com.au.

Shipping

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