RC-505 - Logic/Mainstage

I am a noob.

If I want to run a guitar through the looper to play bass/guitar, how do I setup logic/mainstage to isolate effects from another? Do I need to assign channels for the same input, so the effects stay on a singular channel? Please help.

If you wish to isolate guitar from bass each with their separated fx rack in Logic, a possible method would to create 2 channelstrips. Each one with an input dedicated for each instrument (one for the bass and the other for the guitar).

Then , using Sends on each of those channelstrips routing to Auxilary channelstrips, onto wich are instantiated the desired/discrete Fx racks.

Those Auxilary channelstrips could then be themselves routed (via their output or their own Sends) to the Looper plugin and/or the main output. If you wish to send both back to the 505, you should use mono outputs, as the latter seems to feature only stereo input (possibly? splittable in 2 monos).

In short the idea here is to use Sends to route and cascade the instruments signals to distinct channelstrips, which (Logic/Mainstage) controls could be used to adjust their blend via their respective (main/Sends) level faders, pans (depending of your specific goal), mutes, etc... in addition to the Fx plugin own controls.