Have you been having some kind of reply since your question?

First of all, you need to plug your guitar in your amp, so you use the line out of your amp to enter the looper, in mic/aux mode (aux in), choose a sound like "voice" and record your loops, but you need a monitor (another amp or hifi system) to listen back your loops...

If you consider a "bypasss" sound of your guitar with the JMP4 , you'll hear the sound "bypass" after recording your loops, got it? (not the sound you've adjusted in your amp, cause it is "after" the looper!)