usb vs toslink?

i have a trivista DAC. or my krell 20i also accept digital input ( coaxial or toslink ), i am fairly happy with the sound of krell, or trivista, so my question is that if i get a hagerman and connect to either dac, would I expect a margiinal or noticeable improvement vs, apple AE to either DAC.
i have try apple AE , it's ok for background music, but not for serious listening

Toslink now comes in two flavors:

1) Plastic
2) Glass

The glass is a quantum leap in fidelity improvement over the plastic. van den Hul Octocoupler is probably the best glass Toslink out there!

is usb to dac ie. hagman better than toslink from apple AE to DAC?

A1126 - if you are not happy with the AE I suggest you try the Hagerman or Blue Circle. You have nice toys and these don't cost much.

As Fatparrot points out, there are (nothing new) two flavors of Toslink - glass and plastic. I ran a Wireworld SuperNova (glass) directly from my Mac G4 to a TriVista and it was excellent - unfortunately I don't think anyone is making a cable this good for the mini-Toslink

van den Hul Octocoupler is available in 3 configurations:

1) Toslink to Toslink
2) Mini to Toslink
3) Mini to Mini

Ckorody, when Toslink first came out, I thought that it was only available in plastic, as opposed to the AT&T Glass cable [not compatible with the Toslink terminations].