The Cayin RU9 is a pocket-sized DAC and headphone amplifier that brings a real vacuum tube into everyday portable listening. Built around a Korg NuTube 6P1, dual AK4493SEQ DACs, and both 3.5mm and 4.4mm outputs, the RU9 is for tube character without giving up modern portability. A magnetic back lets it ride on your phone, and an internal battery means it works whether you're on the move or at a desk.
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