DigiTech DIGIDELAY Manual page 10

Loop Delay
The Mode knob's 7-LOOP setting is used to create an infinite delay
loop up to four seconds long. Once a loop is created, you can add
overdub parts to it. To use the Loop feature, follow these steps:
1. Select 7-LOOP using the MODE (5) knob.
2. Begin with the effect bypassed. Press and hold the Pedal (8) and
immediately begin playing. The Indicator LED (10) is lit solid red.
3.When you reach the end of your loop, release the Pedal. The passage
plays back in an infinite loop, and the Indicator LED flashes red.
4.To add overdubs to the existing loop, press and hold the Pedal at any
time and begin playing. The Indicator LED is lit solid red as long as
the pedal is held, indicating that anything played will be added to the
loop.
5.To stop the loop, quickly press the Pedal. This puts the DigiDelay
into Bypass. The loop stops playing and the delay loop memory is
cleared.