Using Lfos And Envelopes (Egs) - Korg NAUTILUS 61 AT Operation Manual

Using LFOs and Envelopes (EGs)

Using LFOs
Each Oscillator has two LFOs: LFO1 and LFO2. There is
also a single Common LFO, shared by both Oscillators.
While LFO1 and LFO2 are separate for each voice, the
Common LFO is shared by all voices in the Program. This
makes it useful when you want all of the voices to have an
identical LFO effect.
You can use these LFOs to modulate different Program
parameters, including:
• Pitch (for vibrato)
• Filters (for wah effects)
• Volume (for tremolo)
• Pan (for auto-panning)
The LFOs can modulate many other parameters, in addition
to those listed above.
Basic LFO programming
The NAUTILUS LFOs are very powerful, and offer lots of
control for the power user. It's simple to get started with
them, though–and the graphics on the LCD show how the
parameters affect the sound. Let's take a brief tour.
1. Go to the OSC1 LFO1 tab of the PROGRAM > LFO
page.
2. Select the Waveform parameter.
3. Use the [+] or [−] buttons to scroll through the
different waveforms, and look at their shapes in the
graphic display.
There are a number of waveforms to choose from. Each are
suited to different applications:
• Triangle and Sine are the classic LFO shapes for
vibrato, tremolo, panning, and filter wah effects.
• Square is useful for gated filter and amp effects, and
creates a police siren effect when modulating pitch.
• The Guitar waveform is designed especially for guitar
vibrato, since it bends only upwards from the base value.
• Saw and Exponential Saw Down are good for rhythmic
filter and amp effects.
• Random 1 (S/H) creates the classic sample-and-hold
effect, which is great for modulating a resonant filter.
4. After looking at the different waveforms, select
Triangle.
Detailed Program Editing Using LFOs and Envelopes (EGs)
5. Select the Shape parameter, and change settings, from
-99 to +99.
Notice how the shape of the waveform becomes more
curved, and how -99 emphasizes the lower part of the
shape, and +99 emphasizes the upper part.
6. Select the Start Phase parameter to sweep through its
range of values.
Notice how the waveform shifts from side to side.
Among other things, this lets you offset the LFOs from
one another in time, which can create interesting organic
effects.
7. Use the Frequency parameter to set the speed of the
LFO.
8. Use the Fade and Delay settings to control the way the
LFO sounds at the beginning of the note.
For more information on LFOs, see "PROGRAM > LFO" on
page 83 of the PG.
All of these parameters control the way that the LFO itself
works. In order for the LFO to actually affect the sound, you
can use the dedicated LFO routings on the Filter, Pitch, and
Amp pages, or use the LFOs as AMS sources for a wide
variety of parameters.
Frequency Modulation
AMS can be used to vary the LFO speed. This lets you
change the LFO speed by operating a controller, or by the
EG or Keyboard Track settings.
MIDI/Tempo Sync.
If MIDI/Tempo Sync is checked, the Frequency setting
will be ignored, and the LFO will synchronize to the system
tempo or external MIDI clocks.
This lets you produce vibrato, wah, auto-pan, or tremolo
effects that lock to the Drum Track, ARP, Wave Sequences,
the internal sequencer, or external MIDI sequencers.
EGs (Envelope Generators)
An envelope creates a modulation signal by moving from
one level to another over a specified time, and then moving
to another level over another period of time, and so on.
note-on Attack Level
Level
Decay Time
Attack Time
Start Level
The HD-1 includes three EGs, for Pitch, Filter, and Amp.
These produce time-varying changes in pitch, tone, and
volume respectively. They can also be used to modulate a
number of other Program parameters via AMS.
note-off
Break Level
Sustain Level
Release Time
Slope Time
Release Level
Time
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