CAYIN Spark HA-2i 16-600 ohms full impedance tube Headphone Amplifier Amp The differential input circuit uses special low-noise FET Toshiba sound, low noise, good sound. power amplifier using high-power low-resistance FET composed of a push-pull class A amplifier circuit, excellent dynamic characteristics. front panel set two 6.35mm stereo headphone output jack, easy to use two headphones while listening to music,built-perfect protection circuit, with a midpoint of drift and delay squelch boot, shutdown, noise cancellation, full protection of the amplifier and headphones Use Japanese original ALPS 16 Type Volume potentiometer, reliable and durable, to ensure quality. Configuring a group of RCA stereo audio inputs. new exterior design, all-aluminum brushed Splendid shell, simple and stylish, and effectively shielded from external interference, external high-power adapter, power supply system to reduce interference to the internal circuitry of the machine