I have a boss gt-1000 core and i´m using the BRIT STACK model. i got the sound how i wanted but I´m a bit confused on the sag control. I never owned a marshall amp so I dont know how should I put the sag. i´ve seen many turn it up and many turn it down, but never at 0. what setting should I put to get the most realistic feel out of it? thanks in advance!