Product Name: Mini stereo audio preamplifier Model No. : AU-10X Input: RCA (L / R) + 3.5mm Output: RCA (L / R) + 3.5mm + headphones Size: 3.42in × 1.96in × 1.45in (87mm × 50mm × 37mm). Powered: DC 9-19V Compatible input devices: DVD, CD, set-top box, MP3, TV, mobile phone, computer, tablet, microphone, phono turntable, sound card, guitar, bass, electronic instrument, game console or other devices. Compatible output devices: Active speakers, Desktop speakers,Subwoofer, Sound blaster, Reverberator, AV receiver, Post-Amp, Headphones, etc. It is a preamp and cannot be used as a power amplifier to drive passive speakers working. What's in the box: AU-10X preamplifier * 1 pcs DC power adapter * 1 pcs It is applicable to power weak signals into line-level signals. The amplification multiples are 10 times (20dB). It can directly drive the headphone to work (the headphone output port can't be used with other output ports at the same time), the max headphone impedance supported is 16 ohm. Using the classic Dual OP AMP NE5532, high frequency electrolytic capacitor, noise reduction circuit design, no background noise, effective gain audio, improve sound quality. Input: RCA (L / R) + 3.5mm, Output: RCA (L / R) + 3.5mm + headphones, Poowered by DC 9-19v, static current about 8Ma. With volume adjustment knob, the volume can be adjusted freely. Small size, easy to carry and use. The size: 3.42in × 1.96in × 1.45in (87mm × 50mm × 37mm). It is a preamp and cannot be used as a power amplifier to drive passive speakers working. Widely compatible with all audio devices. Input: DVD, CD, set-top box, MP3, TV, mobile phone, computer, tablet, microphone, phono turntable, sound card, guitar, bass, electronic instrument, game console or other devices. Output: speakers, subwoofer, Sound Blaster, reverberator, AV receiver, Post-Amp, Headphones, etc.