As is the case with all adjustments:'' it depends''. In this case it
depends from the headshell ''screws accomodation'' and carts
screw holes construction. BTW AT headshells have screw threads
at the under side. So in your terminology in those headshells all
carts must be fastened ''upside down''. There is no ''up'' and ''down''
in absolute sense. Those are our ''mental orientation'' words . But
language and reality are different things.