DDL & Modulation Effects

Digital delays basically store samples for a set period of time and then they output them. The samples are stored in RAM.
Digital Delay Lines (DDL's) produce a wide variety of effects. They are all classed as time-based effects.

Creating DDL Effects

Delay

Modulation depth and rate set to zero.
Adjust the delay time to the desired setting.
The feedback control adjusts the amount of repeats.

Chorus

Chorus was developed to mimic the differences in timing and pitch when two or more instruments or voices try to play the same thing at the same time.

Delay of a few tens of milliseconds.
Modulation around 3kHz.
Direct and delayed sound should be mixed equally.
Chorus works well if the effect output is panned to one side and the dry signal is panned to the other. If you use two chorus units and pan their outputs hard left and right the effect is increased, especially if their modulation times are slightly different.

Vibrato

The same process as chorus, but without any of the dry sound.

Keep the delay time short (less than 10ms).
Since there is no dry sound required, the DDL is either patched into the insert point rather than an auxiliary or the routing buttons on the original channel are switched off.

Phasing

The direct and delayed sounds should be at equal volume.

Delay time of around 3 to 10ms.
Slow, shallow modulation.
No feedback.
True 'through-zero' phasing needs two delay units being fed the same signal. Set both to an identical, short delay (around 5 ms) with their outputs being mixed to mono at identical levels. Modulate one of the delays either by LFO or manually; this simulates the original tape-based effect. Also experiment with the basic delay time.

Flanging

Similar to phasing, but…

Use slightly longer delay times (up to 50ms).
The feedback control is used to add the swirling, 'jet' sounds.
As with phasing, flanging works well with the effected sound panned to one side and the dry sound panned to the other.
If there is a 'phase invert' button, this allows different frequencies to be accentuated by the filtering process. It's a matter of taste whether you prefer it on or off.

ADT

Automatic Double Tracking is similar to chorus, and is designed to give the illusion of two instruments or voices playing together.

Delay time of around 100ms.
Slight modulation for a hint of pitch wavering.
Mixed with the dry signal.