Join Date: Dec 2000
Location: Toronto, Ontario, Canada
Disengaging a Backstop would change the neutral position of the trem (which of course equals instantly out-of-tune to the sharp side on a floating bridge) being as it exerts a spring-loaded force opposite that of the trem springs (push me/pull you).
A Tremol-No is turned on for hard-tail mode, and (if set up correctly) 'vanishes' from the equation completely when disengaged, allowing for full float, flutter, all that good stuff.
The Backstop is an instant flutter-remover if it's set up with any strength at all...