{"product_id":"mass-kobo-model-491","title":"MASS-kobo Model 491","description":"\u003cp\u003eThe MASS-kobo Model 491 is the successor to the flagship Model 465, a twin-balanced monoblock headphone amplifier with four high-performance amplifier stages and fully independent left and right power supplies, a topology more commonly found in high-end loudspeaker amplifiers than in headphone designs. Delivers over 3.5 W + 3.5 W into 32 Ω balanced, enough to drive the HIFIMAN Susvara at reference quality. Made-to-order in Japan.\u003c\/p\u003e\n\u003ch3\u003eType and Technology\u003c\/h3\u003e\n\u003cp\u003eTwin-balanced monoblock headphone amplifier. Four high-performance amplifier stages (two per channel) with fully independent left and right power supplies. Lead-free solder throughout. Inputs: balanced XLR (electronically balanced, switchable reference input level +4 dBm \/ -10 dBm) × 2, unbalanced RCA × 2. Outputs: XLR 4-pin balanced stereo × 1, XLR 3-pin balanced L\/R × 2, new 4.4 mm balanced × 1, and 1\/4-inch TRS single-ended × 1. Three-stage gain selector (LOW \/ MID \/ HI). Universal AC 100-240 V power supply.\u003c\/p\u003e\n\u003ch3\u003eSound Character\u003c\/h3\u003e\n\u003cp\u003eA clean, stress-free presentation that the manufacturer describes as making the listener \"forget the amplifier is even there.\" The independent dual-mono power supplies and twin-balanced topology contribute to a vanishingly low noise floor and exceptional channel separation: the conditions under which low-efficiency planar magnetic headphones reveal their full dynamic and tonal range without the amplifier imposing its own character.\u003c\/p\u003e\n\u003ch3\u003eBuild and Connectivity\u003c\/h3\u003e\n\u003cp\u003eCompact desktop chassis at 330 × 247 × 104 mm, weighing 6.1 kg without power cable. Front-panel headphone outputs cover every common balanced and single-ended standard so the Model 491 partners with virtually any modern headphone cable terminations. Designed and hand-built by MASS-kobo in Shizuoka, Japan. Each unit is made to order and typical lead time is one to four months depending on parts availability.\u003c\/p\u003e\n\u003ch3\u003eBest For\u003c\/h3\u003e\n\u003cp\u003eReference-system listeners pairing the most demanding low-efficiency planar magnetic headphones: including the \u003ca rel=\"noopener\" title=\"Dan Clark Stealth\" href=\"https:\/\/www.mimic-audio.com\/products\/dca-stealth\" target=\"_blank\"\u003eDan Clark Audio Stealth\u003c\/a\u003e, \u003ca title=\"Hifiman Susvara Unveiled\" href=\"https:\/\/www.mimic-audio.com\/products\/hifiman-susvara-unveiled\"\u003eHiFiMan Susvara Unveiled\u003c\/a\u003e, and similar, with a dedicated headphone amplifier engineered to the standards of a high-end speaker amplifier. The dual XLR 3-pin outputs also make the Model 491 directly suitable for cables that split into separate left\/right balanced runs.\u003c\/p\u003e\n\u003ch3\u003eWhat's in the Box\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003eMASS-kobo Model 491 headphone amplifier\u003c\/li\u003e\n\u003cli\u003ePower cable (standard accessory)\u003c\/li\u003e\n\u003cli\u003eDedicated Pelican case for transport and storage\u003c\/li\u003e\n\u003cli\u003ePelican shipping carton\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003eSpecifications\u003c\/h3\u003e\n\u003ctable\u003e\n\u003cthead\u003e\n\u003ctr\u003e\n\u003cth\u003eSpecification\u003c\/th\u003e\n\u003cth\u003eValue\u003c\/th\u003e\n\u003c\/tr\u003e\n\u003c\/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003eType\u003c\/td\u003e\n\u003ctd\u003eTwin-balanced monoblock stereo headphone amplifier\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eInputs\u003c\/td\u003e\n\u003ctd\u003eXLR 3-pin balanced (electronically balanced) × 2; RCA unbalanced × 2\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eOutputs\u003c\/td\u003e\n\u003ctd\u003eXLR 4-pin balanced × 1; XLR 3-pin balanced L\/R × 2; 4.4mm balanced × 1; 1\/4-inch TRS × 1\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eInput impedance\u003c\/td\u003e\n\u003ctd\u003e3.7 kΩ (XLR balanced) \/ 20 kΩ (RCA unbalanced)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eReference input level\u003c\/td\u003e\n\u003ctd\u003eBalanced: +4 dBm \/ -10 dBm (switchable); Unbalanced: -10 dBm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eMaximum input level\u003c\/td\u003e\n\u003ctd\u003eBalanced: +30 dBm (XLR); Unbalanced: +20 dBm (RCA)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eMaximum output (P-P)\u003c\/td\u003e\n\u003ctd\u003eUnbalanced 22 V P-P; Balanced 32 V P-P (32 Ω, 1 kHz, THD+N 0.05%)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eMaximum output (RMS)\u003c\/td\u003e\n\u003ctd\u003eUnbalanced 7.4 V; Balanced 10.7 V (32 Ω, 1 kHz, THD+N 0.05%)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eMaximum undistorted output\u003c\/td\u003e\n\u003ctd\u003eBalanced ≥ 3.5 W + 3.5 W; Unbalanced 1.8 W + 1.8 W (32 Ω, 1 kHz, THD+N 0.05%)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eResidual noise (Bal. out)\u003c\/td\u003e\n\u003ctd\u003e90 μV (Gain LOW, Vol MIN) to 490 μV (Gain HI, Vol MAX)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFrequency response\u003c\/td\u003e\n\u003ctd\u003e10 Hz - 100 kHz (-0.5 dB); 17 Hz - 50 kHz (-0.2 dB)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eGain settings\u003c\/td\u003e\n\u003ctd\u003eLOW \/ MID \/ HI\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003ePower supply\u003c\/td\u003e\n\u003ctd\u003eAC 100-240 V, 50 \/ 60 Hz; 0.9 A at AC 100 V\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eDimensions\u003c\/td\u003e\n\u003ctd\u003e330 × 247 × 104 mm (excluding protrusions)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eWeight\u003c\/td\u003e\n\u003ctd\u003e6.1 kg (unit only); 11.2 kg packed\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eConstruction\u003c\/td\u003e\n\u003ctd\u003eHand-built, made-to-order, lead-free solder\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eMade in\u003c\/td\u003e\n\u003ctd\u003eShizuoka, Japan\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003ch3\u003eOptions\u003c\/h3\u003e\n\u003cp\u003eThe Model 491 is a hand-built, made-to-order product with a one-to-four-month lead time depending on parts availability. Pricing reflects the international MASS-kobo USD list price and is subject to revision in line with the manufacturer's pricing.\u003c\/p\u003e","brand":"MASS-kobo","offers":[{"title":"Default Title","offer_id":53493079900439,"sku":null,"price":20000.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0213\/4262\/files\/11-1.jpg?v=1780710336","url":"https:\/\/www.mimic-audio.com\/products\/mass-kobo-model-491","provider":"Mimic-Audio","version":"1.0","type":"link"}