Vortex Sound Research

I’ve tried multiple iPads and iPhones as well as a couple different audio interfaces including the Roland Go Mixer Pro and the camera connection kit with my regular USB interface - both let me record hardware synths directly in but I always get random pops and clicks ruining the take. Louder input volume seems to make them more frequent but no matter what they almost always occur. Any suggestions to avoid this, I just want a simple quick way to record videos, and I know plenty of people on Instagram use a similar setup without issue. Thanks!