Feature:1. SAME INPUT AND OUTPUT: This machine adopts the circuit pre attenuation compensation and tone NE5532, when the power is off, the attenuation is 15db, when the power is on, the NE5532 amplifies the compensation, and the gain is 0db, that is, the input and output signals are the same2. LOW POWER CONSUMPTION: The DC power supply should try to use a excellent low ripple power supply. When the input signal amplitude is less than 1v, 12v power supply is sufficient. When the input signal is greater than 1v, please increase the power supply voltage, the maximum power supply voltage is 24v3. EASY SETUP: No special software, apps or drivers needed to install, a true plug and play digital audio adapter4. WIDELY COMPATIBLE WITH ALL AUDIO DEVICES: Inputs fit DVDs, CDs, set top boxes, MP3s, TVs, cell phones, computers, tablets, turntables, sound cards, guitars, basses, electronic musical instruments, game consoles or other devices. Output suitable for speakers, subwoofers, Sound Blasters, reverbs, AV receivers, post amps, headphones, etc.5. VOLUME CONTROL: Full metal housing can ensure good quality, with bass and treble control, can be used as preamp or volume controller for PC, for OS X, or computerSpecification:Item Type: Mini Stereo Audio PreamplifierInput: RCA (L or R) and 3.5mmOutput: RCA (L or R) and 3.5mm and phonePower Supply: DC 12VCompatible Input Devices: DVD, CD, set top box, MP3, TV, cell phone, computer, tablet, turntable, sound card, guitar, bass, electronic musical instrument, game console or other device.Compatible Output Devices: Speakers, Subwoofers, Sound Blasters, Reverbs, AV Receivers, Post Amplifiers, Headphones, etc..Package List:1 x Mini Stereo Audio Preamplifier