Can I use Phono in

[foreright]

My son wants to connect his laptop to his HiFi system to play streamed music from the net.
Unfortunately he has already used the Aux in for his Sky audio out.
He has 2 alternatives (the way I see it)
a) mini jack plug - twin RCA to Phono in of Amp, or
b) to TV audio in.
This obviously crude but. Would the TV audio in switch to audio out or could he use the phone in on the amp or are the voltages different to aux in.

 

[foreright]

Thanks for the reply. I have just found a phono switcher that he can use. He can switch apps between the Aux input.