I finally, after all this time, got round to buying an audio interface and a decent microphone.  I finally plumped for the Roland Firewire FA-66 and an AKG Perception 200.  Got them home, fired up the Powerbook, hooked the mic up to the interface, set my sound input source to Edirol FA-66 (instantly recognised) and started GarageBand ...... and nowt.  Zilch.  Nada.

The mic is properly plugged into the interface, I have the phantom power on, recording rate is set to 96, all outputs are on full and no amount of switching the mix between monitor and direct seems to have an effect.  Unplugging the mic registers as a wee spike in the Powerbooks input levels but otherwise no signal.  The lead for the mic is brand new.  I tried DI'ing my guitar with the same results.  Nada.  I've yet to test the headphones to see if a monitor signal is coming through at all but thus far, no sound. 

Any suggestions, before I take it back to the shop and bounce it off the blokes head.  Repeatedly.

PB

Did you try calling the audio interface tech support or maybe an update on the driver if it needs one.Are all the levels up? Good luck!!!