True Tube Amplification: The preamp circuit elevates the voltage to 54V, ensuring the tubes work to their full potential, delivering a warm and rich experience. The unique preamplification technology delivers pure audio signals, faithfully reproducing crisp high tones, full midrange richness, and deep, rhythmic bass. (Important Tips: Remove the copper rings for effortless installation of the tubes on the P3.) Bluetooth 5.1: Equipped with the Qualcomm QCC3031 chip, the P3 preamp guarantees impressive wireless sound quality and low latency, with compatibility for aptX HD and aptX LL codecs formats. Furthermore, the inclusion of a manual reset button prevents accidental connections by others, enhancing connection reliability. Versatile Connectivities: The P3 provides Bluetooth/RCA inputs and RCA/AUX OUT/3.5mm headphone outputs. It can help create a 2.1-channel audio system by connecting active speakers/an amplifier and a subwoofer. As a headphone amplifier, it supports headphones with impedance ranging from 16Ω to 300Ω. Premium Components: It utilizes ELNA audiophile-grade capacitors and taper A pot. The bass and treble controls boast central detents for tone-defeating. With an SNR of up to 103dB and a crosstalk of 95dB, it helps form a HiFi audio system when paired with the V3 amplifier of the same series. What You'll Get: Fosi Audio P3 Tube Preamplifier x1, User Manual x1, 5654W Vacuum Tube x2, 12V/1.5A Power Supply x1, a 24-month worry-free warranty and responsive customer service.