[QUESTION] Recording guitar: what am I doing wrong?

I’m a synth guy, so I’ve always dealt with line level signals at my studio. My friend is an amazing guitar player, but he doesn’t know much about recording. We tried recording his guitar at my studio and we’re running into clipping issues.

First, my signal path may look a bit weird. So he plugs the guitar in my Behringer XR18 digital mixer. From there, it goes to a dirt chain (aux send + reamp box), back to the mixer and to the chorus/delay/reverb chain (aux send + reamp box), then finally back to the mixer. Last time we skipped the dirt chain though, and just used a chorus and a reverb. Then it all goes into an iPad with software amp and cab.

I’ve tried adding 25 dB gain to the initial guitar input plus a few dB to the CDR input, yet it’s quite quiet compared to my line level instruments. And software amps (we’ve mostly used Tonestack) clip a lot even at low gain.

Obviously, I’m doing something wrong. How do I make the guitar loud enough without clipping when playing through pedals with reamp boxes and a digital mixer? How do I record it correctly?