Modulation Effects

Modulation effects are created by a dry signal and delayed signal mixing when one or both are slightly detuned.

This can create a number of effects such as: 

• Chorus
• Flanger
• Phaser
• Vibrato 

The name comes from the way it makes one instrument sound like a group or ensemble. 

Two main controls: 

• Depth: the amount of pitch modulation
• Rate: how fast the delayed signal plays (oscillation rate) 

You can hear this effect on the rhythm guitar on Fleetwood Mac's Rhiannon. 

Phaser

Can produce similar effects to both a chorus and flanger depending on the settings.

A subtle setting is most common and can produce a shimmering sound. 

Flanger

Gives a swirling or wooshing effect to the signal. 

Works by feeding the wet signal back through the unit using the regeneration or feedback control.

The rate of the LFO is set using the rate control. 

Uses an LFO to modulate the frequency of a signal. 

The extent of the modulation is set by the depth control, while the rate can set the modulation in Hz or in time with the music.