Ferrum Audio OOR Headphone Amplifier

The Ferrum OOR headphone amplifier is a masterpiece of engineering, housed in a robust Corten steel housing with an elegant anodized aluminum front. This high-quality front panel has a minimalist design and only has three control knobs: one for adjusting the gain to suit different headphones, a switch for switching between balanced and unbalanced modes, and a precise volume control. According to the manufacturer Ferrum, the OOR effortlessly drives even the most demanding headphones, setting new standards in audio quality and ease of use.

Fully symmetrical signal path

The Ferrum OOR offers a fully symmetrical signal path, which is ensured via both the XLR and RCA inputs. This leads to significantly better sound quality, as disruptive influences and signal losses are minimized. The symmetry in the signal path makes a decisive contribution to ensuring that the sound is reproduced extremely precisely and clearly.

Ferrum Power Link (FPL) technology

A special highlight of the OOR is the Ferrum Power Link (FPL) technology, which allows the amplifier to be operated with the optionally available HYPSOS power supply. By connecting to HYPSOS, the OOR can develop its full performance potential and offer unprecedented musicality and dynamics. The FPL cable used for this connection ensures a constant voltage supply and eliminates the negative influences of cable resistance.

Balanced and transparent sound signature

The Ferrum OOR is designed to deliver a balanced and very transparent sound signature. This means that every nuance of the music is reproduced in detail without causing listening fatigue. The amplifier offers extremely low distortion and enormous dynamics, resulting in the ultimate listening pleasure.

Easy handling

The OOR is extremely simple and intuitive to operate. The most important settings can be made using just three buttons on the front. This includes adjusting the gain, switching between symmetrical and asymmetrical operation, and volume control.

Own amplifier technology

The OOR's amplifier technology was developed in-house at Ferrum and features discrete power amplifier technology. This technology ensures the best possible analog sound quality and enables precise control of the output transistors. This reduces distortion to an inaudible level and allows the transistors to develop their full power immediately, which ensures high dynamics and superior sound control.

Technical data

• Gain: -4dB, +6dB, +16dB balanced; -10dB, 0dB, 10dB unbalanced
• Circuit: Fully symmetrical, proprietary discrete power amplifier technology
• Inputs: XLR, RCA, 2.5 mm power jack (positive inside), special 4-pin jack for DC power
• Headphone outputs: 4-pin XLR, 6.35-millimeter jack
• Frequency response: 20Hz – 100kHz at ±0.1dB
• Output power: 400mW at 300O, 2W at 60O unbalanced; 1,600mW at 300O, 8W at 60O balanced
• Input impedance: 94kO
• Output impedance: 22O preamp output (unbalanced), 44O preamp output (balanced), < 0.3O headphone outputs
• Power consumption: <15W at idle
• Power supply: 100/240V AC to 22-30V DC
• Dimensions (W/H/D): 21.7 x 5.0 x 20.6 cm
• Weight: 1.8kg

Special features and accessories

The Ferrum OOR comes with a carefully selected DC power adapter that already ensures excellent performance. However, to get the absolute maximum out of the amplifier, it can be connected to the HYPSOS power supply via the proprietary Ferrum Power Link DC power cable. This FPL cable, which can be ordered separately, ensures a constant voltage and optimizes the power supply to the amplifier.

In summary, the Ferrum OOR is an outstanding headphone amplifier that impresses with its combination of innovative technology, ease of use and excellent sound quality. Whether in combination with the HYPSOS power supply or operated independently - the OOR sets new standards and redefines the headphone amplifier category.