I gig with my amp up pretty loudly so I hear when something changes pretty well, and it’s something I haven’t quite figured out yet. I feel like sometimes I stumble on patches that color the sound a little bit or maybe just cut the volume, I’m not sure. I use my H90 in dual mode and have it in the FX loop. One of the things that took me a second to figure out was that when I had the P Bypass on DSP mode, it would color the sound severely. Big bass cut, kinda shrill top end, it sounded bad tbh.
Turning the bypass to Relay mode completely fixed this problem. I have good gear and I have a good signal chain – I have a buffer at the end of my chain going into the front of the amp, and my amp has a buffered FX loop. The DSP mode turns the H90 buffer on, so maybe it’s possible that it was just putting too much juice into an already healthy signal and made it sound weird, I’m not quite sure. But I do know that the relay bypass is true bypass and completely takes the signal out. Regardless, it might be worth messing around some of the global bypass/buffer settings and see if you have any luck
