12. Synthesis basics: The Amplifier
NORD MODULAR G2 V1.1
Page 212
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An amplifier is most often used at the final stage of a synth signal chain, to control volume. By modulat-
ing the amplifier with an envelope, the sound can be given its basic “shape”. In fact, the “volume shape”
is one of the most important factors to how we identify the sound. By setting up a proper volume enve-
lope you can make a sound “soft”, “hard”, “plucked” “static” etc.
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Envelopes are used to modulate pitch, amplitude, filter cutoff and other parameters in a sound. This is
used to give the sound a varying character from the moment the key is pressed to the moment it is re-
leased.
The classic synthesizer envelope has four parameters, Attack, Decay, Sustain and Release, and is therefore
often referred to as an “
ADSR-envelope
”.
When you press a key, the envelope is
triggered
. This means is starts rasing from zero to maximum level.
How long this should take, depends on the
Attack
setting. If the Attack time is set to “0”, the envelope
will instantly reach full level. If it is raised it will take longer.
If you for example have an envelope controlling volume, raising the attack will give the sound a “softer”
character. If you have the envelope routed to the filter, it might give the sound a “wah” type of start.
The volume envelope curve (to the left) determines how the amplitude of the waveform changes over time.