Reference Manual

412 Live Instrument Reference
The overall intensity of the LFO is set by the LFO Amount control in the shell. This parameter
scales both the Dest. A and B amounts and can be modulated by note velocity via the display’s
Amt<Vel control. The LFO’s intensity is also affected by its envelope.
24.6.4 Envelopes
Operator has seven envelopes: one for each oscillator, a filter envelope, a pitch envelope and
an envelope for the LFO. All envelopes feature some special looping modes. Additionally, the
filter and pitch envelopes have adjustable slopes.
Each oscillator’s volume envelope is defined by six parameters: three rates and three levels. A
rate is the time it takes to go from one level to the next. For instance, a typical pad sound starts
with the initial level “-inf dB“ (which is silence), moves with an attack rate to its peak level, moves
from there to the sustain level with a decay rate, and then finally, after note-off occurs, back to
“-inf dB“ at the release rate. Operator’s display provides a good overview of the actual shape
of any particular envelope and lets you directly adjust the curve by clicking on a breakpoint and
dragging. The breakpoints retain their selection after clicking, allowing them to be adjusted with
the keyboard’s cursor keys, if desired.
Hint: Envelope shapes can be copied and pasted from one oscillator to another in Operator us-
ing the [right-click](PC) / [CTRL-click](Mac) context menu.
As mentioned above, the filter and pitch envelopes also have adjustable slopes. Clicking on the
diamonds between the breakpoints allows you to adjust the slope of the envelope segments.
Positive slope values cause the envelope to move quickly at the beginning, then slower. Nega-
tive slope values cause the envelope to remain flat for longer, then move faster at the end. A
slope of zero is linear; the envelope will move at the same rate throughout the segment.
With FM synthesis, it is possible to create spectacular, endless, permuting sounds; the key to do-
ing this is looping envelopes. Loop Mode can be activated in the lower left corner of the display.
If an envelope in Operator is in Loop Mode and reaches sustain level while the note is still being
held, it will be retriggered. The rate for this movement is defined by the Loop Time parameter.
(Note that envelopes in Loop Mode can loop very quickly and can therefore be used to achieve
effects that one would not normally expect from an envelope generator.)
While Loop Mode is good for textures and experimental sounds, Operator also includes Beat
and Sync Modes, which provide a simple way of creating rhythmical sounds. If set to Beat
Mode, an envelope will restart after the beat time selected from the Repeat chooser. In Beat
Mode, the repeat time is defined in fractions of song time, but notes are not quantized. If you