Tube Phono Preamplifier: converts phono signals to Line Level Signals with Low-noise integrated circuits and high-quality components to remove low-frequency noise ensure clear sound quality; The Gain Setting: 4-levels of output level setting (OFF/39/42/45 dB). It can keep the purity of the sound and avoid the resistor influence. Two Input Way: preamplifier input(CD/DAC/Phone/TV etc.), MM input. The preamp comes with a 12V power supply.MM Grounding post to protect your MM. Matched Tubes: Tubes can be replaced by JAN 5654W/6K4/6J1/6J4/GE5654/6AK5/66*In tubes etc, Different tubes with different sounds. High-Quality After-sale Service: 24 months warranty and 24 hours after-sale service online to provide you a great shopping experience.