Multifunctional DAC Preamplifier: The 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. High-Resolution Decoding: With 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. Advanced Bluetooth with Low Latency: 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. Compact yet Creativity: 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. User-Friendly Design: The 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.