how to connect ipod or smart 4n to the audio player

Any setup, car cassette, radio also have audio switching stage. It can be analog or digital, it doesn’t matter, first of all u have to identify what is that. So every setup or audio device has two or more function. Tuner, CD, Tape, like that. This all stage has their own audio free out signal till
audio switching stage. So you have to identify what is the tuner audio out is. So after identifying the printed path disconnect the connection between tuner stage and audio switching stage. Then arrange the connection as bellow.     

Then use 3.5 stereo cabal to connect your mp3 player and audio device.

When u insert the input jack it will automatically connect to the audio switching stage and u can get super quality output from the player. Low noise and you can adjust the volume and control the sound with same equalizer. Enjoy it