1、Audio Preamp: Enabling 10 times amplification for the audio signal, that is, 20dB. Can directly drive the headphone and supports 16ohm maximum headphone impedance. 2、Pretty Sound: Using dual op amp NE5532 with high frequency electrolytic capacitor and noise reduction circuit design to improve sound quality with high audio gain. 3、Reliable Use: RCA L and R, 3.5mm input and RCA L and R, 3.5mm, phone output. Powered by DC 9‑19V, the static current is about 8mA. Also has volume adjustment knob. 4、Wide Utility: Allows for input from DVD, CD, set top box, cell phone, etc. as well as output to speakers, sound blasters, AV receivers, post amplifiers and so on. 5、Easy Carrying: Designed to have a compact size of 87 x 50 x 37mm, the lightweight stereo preamp is very convenient to carry and use. Item Type: Audio Preamplifier Input: RCA, L and R; 3.5mm. Output: RCA, L and R; 3.5mm; phone. Power Supply: DC 9-19V Compatible 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. 1 x Audio Preamplifier