i've build 15w amp from TDA 2030 but currently i measure from input line to ground (measure are performed from audio jack), reaching 400 mV, my question is:
-is that normal? how i can remove it? even with decoupling cap it's still 400 mV and what is this called? Input offset votage and current?
-can i use another voltage divider in between 1 uF cap decoupling and pin 1 to the ground to remove it?
-how much current and voltage that emmited by amplifier circuit are acceptable for phone or any media player?
This is the image that i use, the red one is the first voltage divider that come default and i thought it was the source of problem?: