Substitute for Waveterminal U24

About a week ago I ordered a Waveterminal U24 to use in converting a USB signal from my computer to a sp/dif signal that I could feed into my Musical Fidelity Trivista DAC. I got a note back today from the company that I ordered from saying that the model had been discontinued. I've done some checking around on the internet and that appears to be true.

Does anyone know of a comparable external device that will do a good job of converting USB to (RCA coax) sp/dif?