Dry ( unaffected )guitar signal is coming through right channel in obs from reaper.

[BobbyIngals]

No matter what I try, I can't get the right channel to have the plug-in effects, just dry signal.

 

[FerretBomb]

Setting up/configuring Reaper is outside the OBS support forums' scope. Probably a better idea to check for a Reaper tech support forum to get that sorted out, it's not something OBS is going to be able to affect... it just takes the signal being provided.