{"product_id":"ferrum-oor-fully-balanced-headphone-amplifier","title":"Ferrum OOR Fully-Balanced Headphone Amplifier","description":"\u003ch1\u003e\u003cstrong\u003e8W headphone amplifier with discrete power stage\u003c\/strong\u003e\u003c\/h1\u003e\n\u003cp\u003eThe Ferrum OOR is an all-analogue headphone amplifier with a fully-balanced signal path and a proprietary discrete power stage. It delivers up to 8W into 60Ω through its balanced output, with three gain settings to accommodate headphones with different sensitivity requirements. XLR and RCA inputs, balanced and single-ended headphone outputs.\u003c\/p\u003e\n\u003ch2\u003e\u003cstrong\u003eAn all-analogue signal path\u003c\/strong\u003e\u003c\/h2\u003e\n\u003cp\u003eThe OOR keeps the audio signal entirely analogue, without signal processing. Its signal path remains fully-balanced whether you connect a source through the XLR or RCA inputs. This lets you use either connection while retaining the amplifier’s balanced internal architecture.\u003c\/p\u003e\n\u003ch2\u003e\u003cstrong\u003eDiscrete amplification with controlled transistor bias\u003c\/strong\u003e\u003c\/h2\u003e\n\u003cp\u003eFerrum’s proprietary discrete power stage uses circuitry that keeps both output transistors conducting. Maintaining this bias helps reduce distortion associated with the transistors switching off and on. The design supports the amplifier’s low-distortion performance and its ability to respond to changing headphone demands.\u003c\/p\u003e\n\u003ch2\u003e\u003cstrong\u003eUp to 8W of balanced output power\u003c\/strong\u003e\u003c\/h2\u003e\n\u003cp\u003eThe balanced 4-pin XLR output delivers 8W into 60Ω and 1.6W into 300Ω. The single-ended 1\/4-inch (6.35mm) output provides 2W into 60Ω and 400mW into 300Ω. A headphone output impedance below 0.3Ω helps limit the amplifier’s influence on a headphone’s frequency response as its impedance changes.\u003c\/p\u003e\n\u003ch2\u003e\u003cstrong\u003eThree gain settings for different headphones\u003c\/strong\u003e\u003c\/h2\u003e\n\u003cp\u003eA front-panel gain control lets you match the amplifier’s voltage gain to your headphones. Balanced operation offers -4dB, +6dB, and +16dB settings, while single-ended operation offers -10dB, 0dB, and +10dB. Lower gain gives sensitive headphones a more useful volume adjustment range, while higher gain accommodates headphones that require a larger voltage swing.\u003c\/p\u003e\n\u003ch2\u003e\u003cstrong\u003eDesigned to pair with HYPSOS\u003c\/strong\u003e\u003c\/h2\u003e\n\u003cp\u003eThe OOR operates with its supplied AC\/DC power adapter and also supports the Ferrum HYPSOS power supply. The proprietary Ferrum Power Link connection allows HYPSOS to perform its 4TSD voltage-sensing measurements deeper within OOR, helping it monitor the voltage delivered to the amplifier. HYPSOS is an optional addition.\u003c\/p\u003e\n\u003ch2\u003e\u003cstrong\u003eDirect controls in a compact chassis\u003c\/strong\u003e\u003c\/h2\u003e\n\u003cp\u003eThe front panel provides a gain knob, volume knob, and input selector for choosing between XLR and RCA sources. Corten steel and anodized aluminum give the chassis its distinctive finish. Measuring 8.6 inches wide (21.7cm), OOR fits comfortably alongside a DAC on a desk or equipment shelf.\u003c\/p\u003e\n\u003ch3\u003e\u003cstrong\u003eProduct highlights\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003eAll-analogue headphone amplification without signal processing\u003cbr\u003e\n\u003c\/li\u003e\n\u003cli\u003eFully-balanced internal signal path with XLR or RCA sources\u003cbr\u003e\n\u003c\/li\u003e\n\u003cli\u003eProprietary discrete power amplifier technology\u003cbr\u003e\n\u003c\/li\u003e\n\u003cli\u003eOutput transistor bias circuitry designed to reduce distortion\u003cbr\u003e\n\u003c\/li\u003e\n\u003cli\u003eUp to 8W into 60Ω through the balanced headphone output\u003cbr\u003e\n\u003c\/li\u003e\n\u003cli\u003eThree selectable gain settings\u003cbr\u003e\n\u003c\/li\u003e\n\u003cli\u003eBalanced 4-pin XLR and single-ended 1\/4-inch (6.35mm) headphone outputs\u003cbr\u003e\n\u003c\/li\u003e\n\u003cli\u003eHeadphone output impedance below 0.3Ω\u003cbr\u003e\n\u003c\/li\u003e\n\u003cli\u003eCompatible with the optional Ferrum HYPSOS power supply\u003cbr\u003e\n\u003c\/li\u003e\n\u003cli\u003eCorten steel and anodized aluminum chassis\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003e\u003cstrong\u003eSpecs\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003eAmplifier architecture: Fully-balanced, proprietary discrete power amplifier\u003cbr\u003e\n\u003c\/li\u003e\n\u003cli\u003eSignal path: All analogue\u003cbr\u003e\n\u003c\/li\u003e\n\u003cli\u003eAnalogue inputs: XLR and RCA\u003cbr\u003e\n\u003c\/li\u003e\n\u003cli\u003eHeadphone outputs: Balanced 4-pin XLR and single-ended 1\/4-inch (6.35mm)\u003cbr\u003e\n\u003c\/li\u003e\n\u003cli\u003eBalanced gain settings: -4dB, +6dB, +16dB\u003cbr\u003e\n\u003c\/li\u003e\n\u003cli\u003eSingle-ended gain settings: -10dB, 0dB, +10dB\u003cbr\u003e\n\u003c\/li\u003e\n\u003cli\u003eBalanced output power: 8W into 60Ω; 1.6W into 300Ω\u003cbr\u003e\n\u003c\/li\u003e\n\u003cli\u003eSingle-ended output power: 2W into 60Ω; 400mW into 300Ω\u003cbr\u003e\n\u003c\/li\u003e\n\u003cli\u003eFrequency response: 20Hz–100kHz, 0.1dB\u003cbr\u003e\n\u003c\/li\u003e\n\u003cli\u003eTHD: Below 0.0003% \/ -110dB at 100mW into 50Ω through the balanced output\u003cbr\u003e\n\u003c\/li\u003e\n\u003cli\u003eInput impedance: 94kΩ\u003cbr\u003e\n\u003c\/li\u003e\n\u003cli\u003eHeadphone output impedance: Below 0.3Ω\u003cbr\u003e\n\u003c\/li\u003e\n\u003cli\u003eSingle-ended preamp output impedance: 22Ω\u003cbr\u003e\n\u003c\/li\u003e\n\u003cli\u003eBalanced preamp output impedance: 44Ω\u003cbr\u003e\n\u003c\/li\u003e\n\u003cli\u003ePower connections: Center-positive 0.10-inch (2.5mm) DC connector and proprietary 4-pin DC connector\u003cbr\u003e\n\u003c\/li\u003e\n\u003cli\u003eIdle power consumption: Below 15W\u003cbr\u003e\n\u003c\/li\u003e\n\u003cli\u003ePower adapter: 100\/240V AC to 22–30V DC\u003cbr\u003e\n\u003c\/li\u003e\n\u003cli\u003eDimensions (W × D × H): 8.6 × 8.1 × 2.0 inches (21.7 × 20.6 × 5cm)\u003cbr\u003e\n\u003c\/li\u003e\n\u003cli\u003eWeight: 3.97lb (1.8kg)\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003e\u003cstrong\u003eWhat’s included\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003eFerrum OOR headphone amplifier\u003cbr\u003e\n\u003c\/li\u003e\n\u003cli\u003eAC\/DC power adapter\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"Ferrum","offers":[{"title":"Default Title","offer_id":67734901981420,"sku":"APS-1451-1","price":2275.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0225\/2721\/3642\/files\/OOR_front.png?v=1791998132","url":"https:\/\/apos.audio\/products\/ferrum-oor-fully-balanced-headphone-amplifier","provider":"Apos","version":"1.0","type":"link"}