Arranging : Time, Tempo, Meter, Key, and Chords : Tick- and Sample-Based Timebases : Switching Timebases

Switching Timebases
All Pro Tools tracks can be switched between being sample-based or tick-based.
Track height affects how various track controls appear in the Edit window. The Timebase selector, which is used for switching a track’s timebase, is only visible in Medium or larger track heights.
To switch the timebase of a track, do one of the following:
*
If the track’s height is set to Medium or larger, click the Timebase selector for the track and select the timebase. The Timebase selector icon changes to reflect your choice.
.
.
– or – 
*
If the track’s height is set to Small (or smaller), click the Track Height selector and select the timebase from the Track Timebase submenu.