Right. That adapter only worked for Macs which used the Omni microphone, such as the Duos. (I think the line-level/PlainTalk inputs started arriving at around the time of the PCI machines, but I do not know for sure). You don't need it for the 2400, because the 2400 has a line level input already. The Apple adapter attenuated line level down to mic level, which the Omni-mic machines required. The good news is that you can get the desired function with any RCA->stereo-mini cable which you could get at any Radio Shack (the cable you'd use to plug a portable CD player into a receiver, except perhaps with female RCA jacks instead). Ivan. ---------------- >Interesting, I did not know that. > >I have never tried to use the microphone input on my >2400. Does that mean that if you have an Apple >microphone RCA adapter that it will also not work? >Those came with the Apple microphone Part # >699-5104-A. Which by the way are available for a few >dollars in surplus stores. >