Envelopes And Ampliier - Novation Ultranova User Manual

In addition to the traditional Low Pass Filter type, there are also High Pass and Band Pass
types. The type of Filter used is selected with the Filter Type parameter.
A High Pass Filter is similar to a Low Pass Filter, but works in the "opposite sense", so that
frequencies below the cut-off point are removed. Frequencies above the cut-off point are
passed. When the Filter Frequency parameter is set to zero, the ilter is completely open
and no frequencies are removed from the raw Oscillator waveforms.
Cutoff
Frequency
Volume
Frequency
When a Band Pass Filter is used, only a narrow band of frequencies centered around the
cut- off point are passed. Frequencies above and below the band are removed. It is not
possible to fully open this type of Filter, and allow all frequencies to pass.
Cutoff
Frequency
Volume
Frequency

Envelopes And Ampliier

In earlier paragraphs, the synthesis of the pitch and the timbre of a sound were described.
The next part of the Synthesis Tutorial describes how the volume of the sound is controlled.
The volume of a note created by a musical instrument often varies greatly over the duration
of the note, according to the type of instrument.
For example, a note played on an Organ quickly attains full volume when a key is pressed.
It stays at full volume until the key is released, at which point the volume level falls instantly
to zero.
A Piano note quickly attains full volume after a key is pressed, and gradually falls in volume
to zero after several seconds, even if the key is held.
KEY "ON"
VOLUME
TIME
KEY "OFF"
A String Section emulation only attains full volume gradually when a key is pressed. It
remains at full volume while the key is held down, but once the key is released, the volume
falls zero fairly slowly.
KEY "ON"
VOLUME
TIME
In an analogue synthesizer, changes to a sound's character which occur over the duration
of a note are controlled by a section called an Envelope Generator. The UltraNova has 6
KEY "ON"
VOLUME
TIME
Envelope Generators (called Env 1 to Env 6). Env 1 is always related to an Ampliier, which
controls the note's amplitude – i.e., the volume of the sound - when the note is played.
Each envelope generator has four main controls which are used to adjust the shape of the
envelope.
Attack Time
Adjusts the time it takes after a key is pressed for the volume to climb from zero to full
volume. It can be used to create a sound with a slow fade-in.
KEY "ON"
VOLUME
SUSTAIN
ATTACK DECAY
Decay Time
Adjusts the time it takes for the volume to fall from its initial full volume to the level set by the
Sustain control while a key is held down.
Sustain Level
This is unlike the other Envelope controls in that it sets a level rather than a period of time.
It sets the volume level that the envelope remains at while the key is held down, after the
Decay Time has expired.
Release Time
Adjusts the time it takes for the volume to fall from the Sustain level to zero once the key is
released. It can be used to create sounds that have a "fade-out" quality.
A typical synthesizer will have one or more envelopes. One envelope is always applied to
the ampliier to shape the volume of each note played. Additional envelopes can be used to
dynamically alter other sections of the synthesizer during the lifetime of each note.
The UltraNova's second Envelope Generator (Env 2) is used to modify the ilter cut-off
frequency over the lifetime of a note.
KEY "OFF"
KEY "OFF"
KEY "OFF"
RELEASE
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