Hey, dont know if this was before and if its normal but my kemper produces quiet noise and with more distortion or more treble ( in this case a treble booster in the stomp section) it get very loud. The funny thing the noise gate dont do anything about it till i damp the sides completly. (example at the beginning) it is with every guitar i have and too if the guitar is plugged of.
cant imagine that its broken cause i had it the whole time in a rackcase but i played concerts with it.
https://soundcloud.com/nw-productions-1
here a example