Hey guys, I've been playing guitar for quite a while, but the bass recently caught my interest, so I got myself an active Harley Benton HBZ-2005.

Video here: https://drive.google.com/file/d/1zHoLlkdbvzgVtrLFdM49qHGZ3DisxX63/view?usp=drive_link

When I turn the knob over there to the right or left (I'll assume this knob controls the EQ), I get a constant buzz. It doesn't matter if I'm playing anything or not; it keeps buzzing until I move the knob to the middle again. Like I said, I'm pretty new to the bass, so I'm not really sure if this is normal with cheap amplifiers (I'm using a Harley Benton HB-20B) or if there's some kind of faulty system and I hope this isn't a silly question. (I already sent an email to the place I bought it from, but I thought it wouldn't hurt to get an opinion from you guys as well.)