{"product_id":"fosi-audio-gr40-tube-dac-headphone-amp-preamp-open-box","title":"Fosi Audio GR40 Tube DAC Headphone Amp\/Preamp (Open Box)","description":"\u003ch2\u003eProduct details\u003c\/h2\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eMultifunctional DAC Preamplifier: \u003c\/strong\u003eThe GR40 is a versatile tube DAC preamplifier and headphone amplifier in one, it supports Bluetooth\/USB\/Optical\/Coaxial inputs and active speakers\/3.5mm headphone output, with a priority mode for headphones.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eHigh-Resolution Decoding: \u003c\/strong\u003eWith the ESS9028Q2M DAC chip, the preamplifier offers superior audio quality and flexibility. The USB sampling rate supports 32Bit\/384kHz and DSD256, making an effective noise reduction to ensure lossless audio every time.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eAdvanced Bluetooth with Low Latency:\u003c\/strong\u003e Featuring the QCC3031 Bluetooth module, it supports aptX, aptX-HD, and aptX-LL codecs to provide detailed and clean audio sound. Also, you can get a relaxed experience with low latency when watching movies.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCompact yet Creativity:\u003c\/strong\u003e With its compact form and a combination of preamp volume, bass, and treble controls, the stereo preamplifier produces a sweeter, more organic sound while preserving the midrange and treble frequencies that make music.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eUser-Friendly Design: \u003c\/strong\u003eThe digital-to-analog audio converter GR40 is designed with user convenience at its core, allowing you to toggle between different audio inputs and restore Bluetooth-a real Plug-and-plug DAC preamplifier without any driver.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3\u003e\u003cimg alt=\"Enjoy The Warm Sound Of Tubes\" src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0065\/4432\/6771\/files\/2-1_copy.jpg?v=1755369443\"\u003e\u003c\/h3\u003e\n\u003cp\u003e\u003cimg alt=\"Chipset\" src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0065\/4432\/6771\/files\/4-1_copy.jpg?v=1755369458\"\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cimg alt=\"Compact Build\" src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0065\/4432\/6771\/files\/5-1_copy.jpg?v=1755369475\"\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cimg alt=\"Diagram Of The Front And Back\" src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0065\/4432\/6771\/files\/7-1_copy.jpg?v=1755369511\"\u003e\u003c\/p\u003e\n\u003ch2\u003eFrequently Asked Questions\u003c\/h2\u003e\n\u003cp\u003e\u003cstrong\u003e1. Bluetooth connection by others, what to do?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eLong press the Bluetooth reset button for 3 seconds; the Bluetooth indicator will flash, and the GR40 will enter pairing mode. Simply re-pair your device.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003e2. Using a smartphone as a source in USB mode, why does sound only\u003c\/strong\u003e \u003cstrong\u003ecome from the phone even when connections are correct?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eCheck if the phone has data transfer enabled. Some models transfer data directly, while others require manual activation of this feature.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003e3. Can headphones and RCA outputs be used simultaneously?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eThe GR40 defaults to headphone priority output. To use RCA output, disconnect the headphones.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003e4. What are suitable tube models for replacement?\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eTubes such as EF95, 6Ak5, 6AK5W, 403A\/403B, 6J1, 6J1P, 6J2, 6J3, 6J4, 6J5 are compatible. You can test and choose according to your personal preference.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eNote:\u003c\/strong\u003e When replacing tubes, ensure the GR40 is turned off and the tubes have cooled down to prevent burns or damage to the product.\u003c\/p\u003e\n\u003ch2\u003eSpecifications\u003c\/h2\u003e\n\u003cp\u003e\u003cstrong\u003eInput \u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eBluetooth, USB, Optical, Coaxial\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eOutput\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eRCA, 3.5mm Headphone Output\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eChannel\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003e2.0\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eSNR\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003e≥103dB\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eDynamic Range\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003e104dB\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eHeadphone Impedance\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003e32Ω-300Ω\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eHeadphone Outout Power\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003e300mW@16Ω 250mW@32Ω\u003c\/p\u003e\n\u003cp\u003e50mW@250Ω 40mW@300Ω\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eFrequency Response\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003e20Hz-20kHz(±1dB)\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eSampling Rtae\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003e32bit\/384kHz; DSD256\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eBluetooth Version\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003e5.1\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eBluetooth Connection Distance\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003e≥10m\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eBluetooth Transmission Format\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eSBC, AAC, aptX, aptX HD, aptX LL\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eVoltage Range\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eDC 12V\u003c\/p\u003e\n\u003ch2\u003ePackage Contents\u003c\/h2\u003e\n\u003cul\u003e\n\u003cli\u003eGR40\u003c\/li\u003e\n\u003cli\u003e5654W Vacuum Tube*2\u003c\/li\u003e\n\u003cli\u003eDecorative Ring*2\u003c\/li\u003e\n\u003cli\u003ePower Adapter\u003c\/li\u003e\n\u003cli\u003eBluetooth Antenna\u003c\/li\u003e\n\u003cli\u003eUser Manual\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"Fosi Audio","offers":[{"title":"Default Title","offer_id":50886343393513,"sku":"GR40 (OB)","price":119.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0065\/4432\/6771\/files\/1-1_8aab53ed-9a91-4a05-a488-a23578c08cf3copy.jpg?v=1755369653","url":"https:\/\/audio46.com\/products\/fosi-audio-gr40-tube-dac-headphone-amp-preamp-open-box","provider":"Audio46 Headphone Store","version":"1.0","type":"link"}