Unfortunately, I stepped on my cord and messed up the 1/4" jack inside my SVT CL and I have to remove the preamp board to remove and replace the jack. However, the control knobs have to be removed first and all come off fairly easy except the frequency knob. I have tried to pull it off but it will not budge and I am afraid of actually damaging the switch if I use much more force. I can't imagine the assemblers using super glue but I'm not ruling that out. Any ideas??