Turbo Trem build small problem

[ficelles]

I have a small issue with my TurboTrem build... everything works as it should with the sole exception that in panning mode + square wave + full depth the right channel doesn't go completely silent as there is some small signal breakthrough and the status LED shows slight illumination. All the other settings work just fine. Any suggestions what might be causing the panning crosstalk into the right channel? Checked for mistakes and solder breaches of course.