{"product_id":"fosi-gr70-tube-headphone-amplifier-preamplifier","title":"Fosi GR70 Tube Headphone Amplifier \u0026 Preamplifier","description":"\u003ch2\u003eThe Fosi Audio GR70 Tube Headphone Amplifier combines classic tube character with modern clarity. Using a dual-stage design with four precision-matched tubes, it delivers natural, transparent sound rich in warmth and texture. Compact, powerful, and beautifully built, the GR70 with tone controls drives a wide range of headphones effortlessly — adding a touch of analogue soul to any digital setup. For greater flexibility and a complete high-fidelity experience, pair it with the\u003cspan\u003e \u003c\/span\u003e\u003ca href=\"https:\/\/theaudio.co\/products\/fosi-zd3-dac-balanced-preamplifier\" rel=\"noopener\" target=\"_blank\"\u003eFosi Audio ZD3 DAC\u003c\/a\u003e\u003cspan\u003e \u003c\/span\u003efor a refined and versatile headphone solution.\u003c\/h2\u003e\n\u003cp\u003eThe Fosi Audio GR70 Tube Headphone Amplifier blends classic tube warmth with modern engineering in a compact, elegant form. Designed for headphone enthusiasts and home-audio listeners alike, it captures the character of vintage amplification while providing clean, controlled power for today’s high-resolution sources.\u003c\/p\u003e\n\u003cp\u003eAt the heart of the GR70 are four vacuum tubes — two 5654W for voltage gain and two 6AC7 tubes for power amplification — forming a two-stage pure-tube topology. This design delivers a smooth, balanced presentation with rich midrange texture, silky treble, and an inviting sense of space. Every note flows naturally, revealing the subtle detail and musicality that make tube listening so distinctive.\u003c\/p\u003e\n\u003cp\u003eDespite its compact footprint, the Fosi GR70 tube headphone amp is a capable performer. It outputs up to 300 mW @ 32 Ω with signal-to-noise ratio ≥ 97 dB, supporting headphones from 16 Ω to 300 Ω across low- and high-impedance modes. Whether driving sensitive IEMs or demanding over-ears, it maintains low distortion and consistent tonal balance.\u003c\/p\u003e\n\u003cp\u003eBuilt from CNC-machined aluminium, the chassis feels reassuringly solid yet refined. Dual-side ventilation keeps the tubes running cool, while tactile controls — volume, bass, treble, and impedance selection — make the amplifier intuitive to operate. Both 6.35 mm and 3.5 mm headphone outputs, plus RCA input\/output, allow integration into desktop or home-hi-fi systems.\u003c\/p\u003e\n\u003cp\u003eFor headphones listeners, the Fosi GR70 tube amplifier offers a perfect meeting of nostalgia and precision. Its glow invites you in; its sound keeps you listening — open, warm, and effortlessly musical.\u003c\/p\u003e\n\u003ch5 class=\"style5\"\u003eFeatures\u003cstrong\u003e \u003c\/strong\u003e\u003cstrong\u003e\u003c\/strong\u003e\n\u003c\/h5\u003e\n\u003cdiv data-motion-enter=\"done\" data-testid=\"richTextElement\" class=\"Z_l5lU ku3DBC zQ9jDz qvSjx3 Vq6kJx comp-m976bmf1 wixui-rich-text\" id=\"comp-m976bmf1\"\u003e\n\u003cdiv data-motion-enter=\"done\" data-testid=\"richTextElement\" class=\"Z_l5lU ku3DBC zQ9jDz qvSjx3 Vq6kJx comp-m976bmfn wixui-rich-text\" id=\"comp-m976bmfn\"\u003e\n\u003csection data-testid=\"section-container\" class=\"xuzjBY comp-m976bmg42 wixui-section Gzsk0j\" data-block-level-container=\"Section\" id=\"comp-m976bmg42\" tabindex=\"-1\"\u003e\n\u003cdiv class=\"comp-m976bmg42-container\" data-testid=\"responsive-container-content\"\u003e\n\u003cdiv data-testid=\"richTextElement\" class=\"Z_l5lU ku3DBC zQ9jDz qvSjx3 Vq6kJx comp-m976bmg65 wixui-rich-text\" id=\"comp-m976bmg65\"\u003e\n\u003csection id=\"comp-m976bmgt\" data-block-level-container=\"Section\" class=\"xuzjBY comp-m976bmgt wixui-section Gzsk0j\" data-testid=\"section-container\" tabindex=\"-1\"\u003e\n\u003cdiv data-testid=\"responsive-container-content\" class=\"comp-m976bmgt-container\"\u003e\n\u003cdiv id=\"comp-m976bmgv\" class=\"Z_l5lU ku3DBC zQ9jDz qvSjx3 Vq6kJx comp-m976bmgv wixui-rich-text\" data-testid=\"richTextElement\"\u003e\n\u003cul\u003e\n\u003cli\u003eFour-tube design using two 5654W and two 6AC7 tubes for pure dual-stage amplification\u003c\/li\u003e\n\u003cli\u003eSupports both low (16 Ω – 120 Ω) and high (120 Ω – 300 Ω) impedance headphones\u003c\/li\u003e\n\u003cli\u003eDelivers up to 300 mW output @ 32 Ω with SNR ≥ 97 dB and THD ≤ 0.5 %\u003c\/li\u003e\n\u003cli\u003eBass and treble controls allow fine-tuning of tonal balance to suit your music\u003c\/li\u003e\n\u003cli\u003eRCA input and output for integration with home hi-fi or powered speakers\u003c\/li\u003e\n\u003cli\u003eFront panel offers both 6.35 mm and 3.5 mm headphone outputs\u003c\/li\u003e\n\u003cli\u003eDurable CNC-machined aluminium enclosure with dual ventilation for thermal stability\u003c\/li\u003e\n\u003cli\u003eCompact 12 V design suitable for desktop or living-room audio systems\u003c\/li\u003e\n\u003cli\u003eHand-finished controls for a refined user experience and classic tube aesthetic\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/section\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/section\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003ch5\u003eSpecifications\u003c\/h5\u003e\n\u003cdiv\u003e\n\u003ctable width=\"100%\"\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003eProduct Type:\u003c\/td\u003e\n\u003ctd\u003eHeadphone Amplifier \/ Pre-Amp\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eTechnology:\u003c\/td\u003e\n\u003ctd\u003eTube\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eInputs:\u003c\/td\u003e\n\u003ctd\u003eStereo RCA\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eOutputs:\u003c\/td\u003e\n\u003ctd\u003eStereo RCA\u003cbr\u003e6.35mm \/ 3.5mm Headphone out\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eMax Power Output:\u003c\/td\u003e\n\u003ctd\u003e300mW @ 32 Ohm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eHeadphone Impedance:\u003c\/td\u003e\n\u003ctd\u003eLow Mode: 16 - 120 Ohm\u003cbr\u003eHigh Mode: 120 - 300 Ohm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFrequency Response:\u003c\/td\u003e\n\u003ctd\u003e20 Hz – 20 kHz (± 0.1 dB)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eTHD:\u003c\/td\u003e\n\u003ctd\u003e\n\u003cspan\u003eHeadphone output: ≤0.5%\u003c\/span\u003e\u003cbr\u003e\u003cspan\u003eRCA output: ≤0.26%\u003c\/span\u003e\u003cbr\u003e\n\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eSNR:\u003c\/td\u003e\n\u003ctd\u003e≥ 97 dB\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eDynamic Range:\u003c\/td\u003e\n\u003ctd\u003e≥ 97 dB\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eTubes:\u003c\/td\u003e\n\u003ctd\u003e2 x 5654W\u003cbr\u003e\u003cspan\u003e2 x 6AC7\u003c\/span\u003e\n\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eOutputs:\u003c\/td\u003e\n\u003ctd\u003eSpeaker binding posts\u003cbr\u003e\u003cspan\u003eSubwoofer output\u003c\/span\u003e\n\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003ePower Supply:\u003c\/td\u003e\n\u003ctd\u003e\u003cspan\u003e12v DC \/ 3 A\u003c\/span\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eDimension (WxHxD):\u003c\/td\u003e\n\u003ctd\u003e\u003cspan\u003e129 × 46 x 192 mm\u003c\/span\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eWeight:\u003c\/td\u003e\n\u003ctd\u003e\u003cspan\u003e0.9 kg\u003c\/span\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFinish:\u003c\/td\u003e\n\u003ctd\u003e\u003cspan\u003eBlack anodised aluminium\u003c\/span\u003e\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\u003ch5\u003e\u003cbr\u003e\u003c\/h5\u003e\n\u003ch5\u003eIncludes\u003c\/h5\u003e\n\u003cul\u003e\n\u003cli\u003e1 x GR70\u003c\/li\u003e\n\u003cli\u003e2 x \u003cmeta charset=\"utf-8\"\u003e \u003cspan\u003e6Ж4\/6Ж8 Vacuum Tubes\u003c\/span\u003e\n\u003c\/li\u003e\n\u003cli\u003e2 x \u003cmeta charset=\"utf-8\"\u003e \u003cspan\u003e5654 Vacuum Tubes\u003c\/span\u003e\n\u003c\/li\u003e\n\u003cli\u003e2 x \u003cmeta charset=\"utf-8\"\u003e \u003cspan\u003eTube Protection Covers\u003c\/span\u003e\n\u003c\/li\u003e\n\u003cli\u003e1 x \u003cmeta charset=\"utf-8\"\u003e \u003cspan\u003e12V\/3A Power Supply\u003c\/span\u003e\n\u003c\/li\u003e\n\u003cli\u003e1 x User Manual \u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/div\u003e\n\u003ch5\u003eSupport\u003c\/h5\u003e\n\u003cul\u003e\n\u003cli\u003e\u003ca rel=\"noopener\" href=\"https:\/\/cdn.shopify.com\/s\/files\/1\/2251\/7913\/files\/GR70--1206.pdf?v=1755592343\" target=\"_blank\"\u003e\u003cspan style=\"font-family: Verdana, Arial, Helvetica, sans-serif; font-size: small; color: #000000;\" color=\"2C2D59\" size=\"2\" face=\"Verdana, Arial, Helvetica, sans-serif\"\u003e\u003cspan class=\"totop\"\u003e\u003cspan color=\"#FFFFFF\"\u003eManual\u003c\/span\u003e\u003c\/span\u003e\u003c\/span\u003e\u003c\/a\u003e\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch5\u003e\u003cspan\u003eAbout\u003c\/span\u003e\u003c\/h5\u003e\n\u003cp\u003eFosi Audio, established in Shenzhen in 2017 by Ryan Huang, has emerged as a pioneering force in democratizing high-fidelity sound. Guided by four core tenets—Foresight, Openness, Sincerity, and Innovation—the brand has cultivated a distinguished presence across 150+ nations. Renowned for exceptional sonic value and community-driven engineering, Fosi integrates premium components from industry leaders like Texas Instruments. Their philosophy transcends conventional audio retail, offering both refined finished products and bespoke DIY solutions for the discerning enthusiast seeking uncompromised quality without premium pricing.\u003cspan\u003e\u003c\/span\u003e\u003cspan\u003e\u003c\/span\u003e\u003c\/p\u003e","brand":"Fosi Audio","offers":[{"title":"Orange Knob","offer_id":44505740574803,"sku":null,"price":21990.0,"currency_code":"INR","in_stock":true},{"title":"Grey Knob","offer_id":44505741590611,"sku":null,"price":16899.0,"currency_code":"INR","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/1867\/3055\/files\/Fosi-GR70-Tube-Headphone-Amplifier-Preamplifier-The-Audio-Co.png?v=1776744890","url":"https:\/\/theaudio.co\/products\/fosi-gr70-tube-headphone-amplifier-preamplifier","provider":"The Audio Co.","version":"1.0","type":"link"}