I recently bought an iMac but I'm having trouble playing my guitar through it.

With my old pc, I had my guitar going through a line 6 pod plugged into the sound card and coming out a stereo system also plugged into sound card.

With the same setup but with an iMac, the only way I can get any sound coming out is if I open Garageband with a real instrument track and turn monitoring on but then there is a delay.

Is it possible to play hear the guitar without any programs running?