The Line 6 POD X3 is VERY QUIET: NO HISS. However, I discovered the hiss reported most by users was due to cables that weren't terribly bad, but just enough out of spec to cause tremendous hissing through the POD. This low level hiss I heard through playing through a vintage tube amp was just accepted as "normal". But, the hiss was unacceptable through the POD. Once I got a few cables changed out, the POD went ABSOLUTELY QUIET at FULL VOLUME. I recorded the entire video through the POD as proof. What I learned about cables is worth passing along. I fact, changing out the cables improved my entire pedal board and I was able to improve the overall quality of sound through the mixer. It doesn't take very expensive cables to eliminate hiss, ground loop, and noise from your set-up.