I am attempting to send a track from Studio One (Pipeline XT Mono) to UFX III (via TM FX) Channel 3 Out into Line In of the Shelford  THEN  sending out of the Shelford to the UFX III Channel 3 (and 4 (-6db Shelford Out) back through TM FX into Studio One via Pipeline where I am attempting to record the results on an audio track via Channel 3 In.  When I set the volumes in TM FX to where I think they should be, I get massive feedback.  When I set lower to avoid feedback I get a distorted unusable extremely low level input.  I messed around with Loopback without any luck.  Over the last 4 days, I have been reading everything I can find and re-watching RME's tutorials and others videos.  For the life of me I just can't figure it out.  Finally tonight, on the assumption that perhaps the Shelford was bad, I set up tests and the Shelford checked out.  So everything is pointing to my lack of knowledge in using the TM FX to set this up properly.  So simply, I am sending a track OUT CH3 and back IN CH3 to record in Studio One utilizing Pipeline Mono.  Any help would be beyond appreciated!  Thanks, Chas.