mac itunes and dCs Elgar Plus

What is the best way to use a dCs Elgar Plus with a Mac and itunes? The Elgar Plus has an firewire interface but i think one can use it only with DSD data. There has been an old thread discussing USB to PCM conversion. In my view a firewire to pcm would be great. Or better firewire directly to the Elgar?
You need to convert USB from your mac to spdif..not pcm ( the dac does that)
Try an M-audio Transit and if you like it you can go to Red Wine or Empirical for mods.
I have not heard the Transit (my dac has a usb input) but I have not read anything but praise for the two modded devices.
Keep in mind that you really should be using losslessly encoded audio files. Using MP3s with a dcs DAC is like trying to drive a Formula 1 race car on diesel gasoline.