amplifier circuit - pls help

[shorabkareem]

I am building a simple preamplifier with TDA2822M IC to power my FM/MP3 player. my question is ? is it necessary to use a (1n4148 swithing diode) to protect my output (music) signal from my MP3 PLAYER. the voltage of my preamplifier is 12+v and my Mp3 player is using 5v.

last time i plug in my mobile phone in to my amplifier. My phone got bursted up? can you please explain why?

tks

 

[D.A.(Tony)Stewart]

Cmos cannot handle any input getting greater than the supply rails due to a buried SCR in the substrate creating a virtual short circuit across supply. But I cannot comment on your circuit.

 

[Jestin_cubetech]

do not use a diode for isolation ,
use 1uF non polar capacitor in input stage.

 

[ZASto]

An the connection with microcontroller is?