I noticed some popping sounds when changing scenes in a particular preset through the last few firmware updates? I finally traced it to the new 'Filter Slope' parameter in the Cab block.
I'm using the Cab 'X/Y' function. Cab 'X' has the 'Filter Slope' set to 6 db/oct and Cab 'Y' has the 'Filter Slope' set to 12 db/oct. There is a popping sound every time a scene causes the cab to go from 'X' to 'Y' and vice versa. Changing the 'Filter Slope' parameters in 'X' and 'Y' to the same setting eliminates the popping sound.
I'm using the Cab 'X/Y' function. Cab 'X' has the 'Filter Slope' set to 6 db/oct and Cab 'Y' has the 'Filter Slope' set to 12 db/oct. There is a popping sound every time a scene causes the cab to go from 'X' to 'Y' and vice versa. Changing the 'Filter Slope' parameters in 'X' and 'Y' to the same setting eliminates the popping sound.