Hi I just got a RME UC and tried connecting my Ti Desktop through the SPDIF but I get clicks under some conditions so had to switch to analog ins. I brought this up at KvR and other users confirmed they also have this problem (and with different interfaces) - here is a test case I can replicate:
Select INIT patch, OSC balance to OSC 1 , Filter 1 to HP now play a high pitch note: say C7 ... turn the resonance up say to 127, and you can 'tune' in the cutoff to hear the clicking (around 80) if you play a different note, you can tune it using the cutoff/resonance
This seems to happen when the Ti is slaved to the RME, if I make it master and set the RME to slave the clicks go away but that negates the whole point of using the RME as master as it also sets the midi clock for everything else on my system and without that the Ti is out of sync. One reason I went for RME is its strong reputation for this sort of thing.