Ferrum presents headphone amplifier OOR


Poland’s Ferrum – falling under the wings of HEM – has released the high-end headphone amplifier OOR, for the real enthusiasts.

The Ferrum OOR headphone amplifier is encased in a corten steel housing with an anodized aluminum front. On that front you will find only three buttons: one for the gain factor to suit your headphones, a switch for balanced / unbalanced and – of course – a volume control. According to Ferrum, the OOR drives even the most demanding headphones effortlessly. Furthermore, much attention has been paid to the power adapter. Internally, the preamplifier in the OOR is built completely balanced; the power amplifier is a discrete specimen.


Another nice feature is that the OOR is upgradeable. Combining it with the Ferrum HYPSOS Hybrid Power System is possible, which should provide even better results.

As for inputs, the OOR has both XLR and RCA and on the output you will find a balanced 4-pin XLR as well as 6.25 jack connectors. THD is < 0.003% / -110 dB at 100 mW in 50 Ohms and the frequency range is from 20 Hz to 100 kHz.

Very cheap, the little gem is not, although we know much higher-priced headphone amplifiers. The Ferrum OOR can be purchased for an amount of €1995. At the time of writing the device is not yet available in the webshop of the manufacturer, but that will undoubtedly change soon.

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