Question

thanks for the very thorough answer @butchrichard ! so I'm going down your list and I'm at the point of testing what we'd call my 'FS2' or my second fire studio unit. All channels send out audio, but I'm getting a NASTY LOUD popping/ticking/click thing, it's horrible. It's coming from channels 9 and 10, which are the left and right SPDIF channels. Even with the 'power button' off for the channels, they're still giving me that dreadful pop. What could that be?

Answer 1

Well SPDIF is a digital signal and Clock Source is important.  It will also depend on what device you connect by SPDIF.

In Universal Control, try changing the Clock Source to External SPDIF.