I’m thinking of line level signals here – lots of amps have line out, or reactive load boxes have them. as far as I know, H9 is designed to work well with both line and instrument levels.
Unless something’s changed (I don’t think it has) the H9 will clip at line level. I had this problem and a few of my loops I can’t use without stepping it down to instrument level. It’s a 50 dollar fix, but a PITA.