Now the stereo can also with cd and amplifier and speakers?

You on the amplifier, audio, speakers, the concept is a little fuzzy, you to give you a stroke.1, audio including: active speakers and passive speakers, active speakers have: amplifier, power supply, amplifier board, speakers in one, belongs to the mobile audio (such as square dance trolley sound). Passive speaker is a wooden box installed inside a few speakers, need to be driven by an amplifier, in order to produce sound. Then there is a split stereo (such as home with a fixed floor stereo), including: amplifier and two speakers. 2, these stereos need audio input to sound, audio sources include: CD, VCD, DVD, mp3, cell phones, etc. (plug-in card need to have a decoder), from the audio output jack to get the audio signal, input to the audio input of the amplifier, amplified by the amplifier, to drive the The speaker is amplified by the amplifier to drive the sound. So no matter what audio, you must configure the audio source to make sound.