Audio expert needed

Hi all, I just posted this in "Anything Goes" but was unsure if it was the right forum, maybe this is more appropiate?

I am trying to feed the audio from my PS2 via the optical out into my macbook audio in using a toslink to 3.5mm cable. I then have a 3.5mm to toslink going from my macbooks audio out into my a/v receiver.

To monitor the sound (hear it from the receiver) i am using Garageband, setting it to record a real instrument track, then selecting "monitoring on".

Only problem is i am not hearing anything (which is a big problem), does anybody know if what i am trying to do is possible, or am i missing something. I am a complete novice when it comes to Garageband (this is the first time i have used it), if anyone knows a simpler solution, other than going directly from my ps2 to the receiver (as i do not have a cable with toslink on both ends) i would love to hear it.

T.I.A