You have to have an Audio Interface between the G1On and your iMac. Think FocusRite or Behringer. A cheapest option is a 1/4" <-> USB adapter. I think you can find them at Amazon for less than $20. When you plug in on a PC, it looks like a normal communication device; speaker and microphone. Of course the speaker doesn't do anything... (at least that's the experience I've had with the ones I've bought)
