Do I need to go from the RP155 to a Hi-Z input on the Octa-Capture?
 
Hi-Z or not to Hi-Z ... that is the question.
 
Thanks

Those effect processors are designed for instrument level input (guitar) and output to a guitar amp input.  Thus one of the front panel Hi Z inputs would be what I would use.

Thank you fireberd. By the way - I'm a steel player too.

BTW, I used to have an Octa-Capture.  LOL
 
I tried one of those for steel and didn't like it.  I use a POD X3 for effects only, no amp modeling with a Carvin BX500 amp and an Eminence EPS-15C speaker.   But I have one POD X3 program (tone as Line 6 calls them) with a preamp that I use for direct to board recording.