The Toslink is the same kind of direct digital connection that can be found on the back of your DVD player or receiver.
All satellite radio receivers (such as the SkyFi) have RCA output to receiver/boombox input.
What this modification does is add a TOSLINK output which lets you create a pure digital connection. The result is audio that is noticeably better than using RCA connections.
Ziggy, I'm interested. Is the mod internal or external (I saw some pics of one person's where they stuck the thing on the back. It was fine for him, but won't work for me.
Any chance that it can be available as a 'kit'?
Just to clarify, this is the SkyFi 2 that I have...
I got the Delphi yesterday. Tried it this morning on my train ride in and it works pretty well. I had 3 bars of signal strength about 95% of the time. It didn't drop out when we went under bridges. Of course I sat on the upper level of the Metra train and on the south facing side and had to hold it up to the window. I need one of those suction things.