If you want digital out like SPDIF--as opposed to a DAC (i.e., digital-to-analog converter)--try the HifiBerry Digi line, any of which should do the job just fi

If you want digital out like SPDIF--as opposed to a DAC (i.e., digital-to-analog converter)--try the HifiBerry Digi line, any of which should do the job just fine. Prices start at ~$25.