SMSL SA 36A Pro TPA TA AMP HIFI Big Power Digital Integrated Tripath Stereo Amplifier with 12V 3.8A Power Adaptor Gold Surface craftsmanship: sand-blast, wiredrawing, oxidation and laser engraving, never fade like paint spraying. Signal input: RCA golden-plated lotus input. Signal output: 4 line signal output. Amplify the sound while listening. 12V Adapter is suitable for general requirements, such as listen to human voice, background music, small supermarket or office music, etc.