Trying to set up a compressor with my new Ultralite Mk5

[savitar]

This is my first time using an audio interface like this so I feel like there's probably some stuff I'm probably missing. I'm trying to process audio from a Shure SM58 through the Ultralite and an outboard compressor (RNC1773). Since the mic doesn't require phantom power I assumed I wouldn't need a preamp. I'm trying to run the mic into the front XLR on the Ultralite, then run a 1/4" TRS cable out from the interface into the in of the compressor, then the another TRS cable out of the compressor into the line-in on the back of the interface. Not having any luck getting this to work. Do I need to get a preamp regardless of phantom power for this to work? Any help would be appreciated

[bayswater]

Yes, you need run the mic signal into a preamp. Why not use the one on the Ultralite?