The mobile phone sound card can be connected to the audio through the audio output of the headphone jack.
General audio has an audio input, that is, you can use mobile phones, VCD, CD and other audio output jacks as a sound source, with audio line input to the power amplifier, so that the power amplifier drives the speaker to release beautiful music.
If you use a mobile phone as a sound source, you can buy a 3.5mm conversion plum plug audio cable, the general digital city has, if there is no can be their own transformation: with a waste mp3 headphone plug and audio braided wire welding, each audio line and then welding a plum plug, insert the audio input of the power amplifier, you can use the mobile phone to play music.