Chapter 3 – Overview of Effects

some of these effects can sound similar to one another depending on the parameter settings, each is achieved differently and can be quite dramatic under the right circumstances. Pitch effects are achieved by splitting the signal into at least two parts, effecting the pitch of one of the parts, then mixing them back together. This eventual mixing is essential since the overall sound of the effect is achieved by the difference between the dry, uneffected signal and the effects signal. Therefore, when using Chorus or Flange, it’s best to keep the Mix control around 50%. Also included in this bank is Auto Pan, which pans a mono signal from Left to Right. This type of effect works best with the Mix control set 100% wet. The various types of Chorus and Flange are:

Stereo Chorus

The Chorus effect is achieved by splitting the signal into three parts with a dry signal and a separate Detuning section for both left and right channels. The detuning is further effected by being modulated by an LFO (low frequency oscillator) which causes the detuning to vary. Many variables are available in this scheme: the Predelay can be varied, the LFO depth can be varied, the LFO speed can be varied, and a portion of the detuned signal can be fed back to the input to increase the effect. Finally, the waveform shape of the LFO can be changed from a smooth sine wave, to a more abrupt squarewave to make the pitch detuning more pronounced.

Some of the MicroVerb 4’s Choruses have individual LFOs controlling the Left and Right sides, set at different rates. These effects, called True Stereo Choruses, often have a wider stereo image than regular Stereo Chorus effects. When the Rate is changed on a True Stereo Chorus, the frequency difference between the Left and Right sides is maintained. Note: These Choruses process the Left and Right sides individually, so any stereo imaging will be maintained.

DRY DELAY SIGNAL

DRY SIGNAL

FEEDBACK

DETUNE

LFO

DETUNE

FEEDBACK

LEFT

CHORUSED

OUTPUT

RIGHT

CHORUSED

OUTPUT

DRY SIGNAL

Quad Chorus

Quad Chorus modulates four delayed signals, each with its phase offset by 90∞ . It gives you twice as much modulation effect as the Stereo Chorus, so it’s great for really fattening up a sound.

Chorus

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MicroVerb 4 Reference Manual

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Alesis MICROVERB 4 manual Stereo Chorus, Quad Chorus