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Introduction Thank you for purchasing the GR40 DAC Tube Preamp and Headphone Amplifier. The GR40 is a powerful and well-designed preamp and headphone amplifier, integrating tube amplification with DAC functionality. It supports multiple input modes, including USB, optical, coaxial, and Bluetooth, making it compatible with a wide range of audio sources.
Package Contents 5654W Vacuum Tube*2 GR40 Decorative Ring*2 Power Adapter GR40 User Manual Bluetooth Antenna User Manual...
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If using headphones, connect them to the GR40's headphone output jack; 5. Power the GR40, press and hold the main knob for 3 seconds to turn on, then press once to switch to the desired input mode (connect to the Bluetooth now if using a Bluetooth device as the source), and set the volume to a low level.;...
6J5 are compatible. You can test and choose according to your personal preference. Note: When replacing tubes, ensure the GR40 is turned off and the tubes have cooled down to prevent burns or damage to the product. If you have any further questions, please contact our support team at...
Warranty and Maintenance Fosi Audio pledges to give a 24-month limited warranty and support from the date of purchase. If you encounter any problem when using our product, please contact our support team at support@fosiaudio.com. About Us Fosi Audio designs and builds innovative audio products with all your music in mind.
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