This is one of my favorite "identical preset" pairs to load into 2 Stompboxes.  The first Crystals instance reverses the input; the second reverses its input once more.  It's a wonderful mix of dry, reversed, and flipped-forward-again delays that are slightly detuned.  Subtle at 25% Mix; increase to 50% for a stronger effect.  Unique, almost "random" delays, courtesy of the Crystals delay buffer configuration.

Preset A

Preset B (identical preset in series)