Please refer to the below link
http://www.allaboutcircuits.com/vol_6/chpt_6/10.html
can anyone help me out with the phono-plug converter as it is written over there, and where do I get it ? I tried googling it, but didn't get anything in reply. Any other suggestion, or optional circuit element, is welcome.

 

I'd start here.

 

Hello,

The shown connector is called a cinch connector:

They are also called RCA or phono connector.

Bertus