Roland VS Recorders- External Effects?

Alright, so I'm a novice in the recording department.. I recently purchased a VS-1680.. It does not have the VS8F-2. I typically just record from the line outs of all of our gear.. I am having a hell of a time running an effects loop from my TC Helicon Unit.. I used to do it with my old Tascam units with no problems.. The manual is no help as it only pertains to the VS8F-2 cards.. Any suggestions?

I have an old Korg D1600 but don't know about the VS-1680. I do miss the simplicity of old recording units. Everything was easy to understand and you just plug it in!