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ABOUT ANALOGUE SYNTHESIS
The “String section” can be seen to go to full volume gradually over several seconds when a key is pressed & then stay there until
the key is released when gradually over a couple of seconds the volume drops to zero.
These curves are called “Envelopes” & in an Analogue synthesiser “Envelope Generators” are used to recreate them. Envelope
Generators have 4 parameters which are used to adjust the shape of the envelope, see the diagram below:
Attack time is used to adjust the time it takes when the key is pressed for the envelope to go from zero to full value. ( Fade in )
Decay time is used to adjust the time it takes for the envelope to go from full value to the value set by the Sustain level. ( Piano
like decay of volume )
Sustain level is used to set the level that the envelope remains at while the key is held down.
Release time is used to adjust the time it takes when the key is released for the level to go from the sustain value to zero. ( Fade
out )
The Supernova II Rack also offers additional envelope features to the classic ADSR types allowing even more flexibility, see the
diagram below:
In addition to the Attack, Decay, Sustain & Release parameters there is also 3 new parameters. These are:
Sustain Rate which is used to control the slope of the “Sustain” phase of the envelope. When this parameter is set to 0 the curve is
normal like so:
When this parameter has a +ve value, during the “Sustain” phase of the envelope the Sustain value will rise to full at a “Rate”
determined by this parameter as can be seen below:
Volume
Key "On"
Key "Off"
Sustain level
Attack
Time
Decay
Time
Infinite Sustain
Time with
no Sustain Rate
Release Time
Attack
Time
Volume
ADSR Type Volume Response Curve
Key "On"
Key "Off"
Decay
Time
Infinite Sustain
Time with
+ve Sustain Rate
Release Time
Sustain level
Volume
Key "On"
Key "Off"
Sustain level
Attack
Time
ADSR Type Volume Response Curve
Decay
Time
Infinite Sustain
Time with
no Sustain Rate
Release Time
Time
Volume
"String Section" Type Volume Response Curve
Key "On"
Key "Off"
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Содержание Supernova II
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