Preview a loop in the trim screen

I received a very nice explanation from Cjaz:

I have found a way to preview a loop in the trim screen.

1. As soon as you bring up your freshly sampled loop. Go to edit (in Trim screen) and choose "loop from start to end"

2. With out changing any settings yet go to the loop screen and turn loop "ON" and then go back to the trim screen. Set your starting position in the trim screen for the beginning of the loop.

3. Go back to the loop screen and choose edit. Pick loop from start to end. (This is making a reference to the trim screen and not the loop screen). You should not have made any changes to the loop screen yet!

4.Now set the end point of the loop in the trim screen. (If you notice, the loop screen now moves according to the trim screen but only for the ending point. If you change the starting point you'll have to go back to the loop screen to and set loop from start to end again)

5. Once you have you initial loop set in the trim screen, you can now go to the loop screen and pick any starting and ending points you want. (The section in the trim screen will now play followed by the highlighted section in the loop screen over and over. (Note: when the start and ending points are different for the trim and loop screens the trim screen will play once followed by the loop screen repeatedly.)