HiFiBerry Digi2 Pro is a high-quality S/PDIF output for the Raspberry Pi. It uses the I2S sound port that connects directly to the CPU without the need for an additional USB conversion.
It also supports our DSP add-on board now that allows to process your audio before sending it to the output.
The board can be equipped with an additional BNC connector. Note that you have to solder this by yourself.