SPDIF to jitter-free MIDI from the ES-4 on Vimeo
2 demos of the new ES4 module, which can use the SPDIFs to multiplex out more than just one CV output and use the output expander as 8 (individual) gate outputs, thats a lot from just one simple almost unused output on most audio interfaces, so check those videos and this page if you do not know about the sleepers yet..
and yes, it’s about controlling analogue synthesisers from your audio interface (well, almost a motu or RME but doesn’t have to..)