Compact headphone amplifier that provides four channels which can be used simultaneously, each of them equipped with separate volume control knob. It provides 3.5mm RCA inputs and 6.35mm stereo output, and is powered by a 12-18V DC power supply. Input impedance: 1000 KΩ (unbalanced). Max. output level: +22 dB. Output impedance: minimum 10Ω (each channel). Max gain: 20-dB (each channel). Signal to noise ratio: >98 dB.