Using UbuntuStudio 18.04.3 with a Focusrite Scarlett 18i20 as my soundcard. I just recently upgraded to 18.04 and I was excited to see that pulse audio now recognizes and allows me to use the Scarlett as my soundcard for applications other than Ardour. The problem is that my monitors are connected to the SPDIF output on the Scarlett and I cannot for the life of me figure out how to get the system sounds and application sounds to output via SPDIF instead of the analog outputs on the Scarlett. The SPDIF works fine in Ardour (they are recognized as Output Channels 11 & 12). But for everything else, pulse is outputting on analog outputs 1-10, sending nothing to SPDIF.