balanced to unbalanced audio

hello
im looking for a simple microchip to convet a balanced audio signal to an unbalanced audio signal, just like the drv134 but the reverse of what it does

 

and how wud u determine the impedance of ur input signal, like frum n ipod?

 

any pro audio shop will carry a balanced to un balanced converter box, they go for about $50. to determine the impedence of an audio signal just get a multimeter, set it to read ohms, and connect the pos and neg to your hot and ground on your audio line.