Specifications

Page 58
Taurus 3 User’s Manual - Glossary
Page 59
Taurus 3 User’s Manual - Glossary
Glossary
Here are a few key terms that cover the basics of sound generation as used in the Taurus 3 synthesizer.
Amplitude – The strength of a sound’s vibration measured in Decibels (dB). Amplitude corresponds to the
musical term Loudness.
Continuous Controller (CC) – A type of MIDI message used to transmit control commands. These com-
mands are digital control signals for parameters such as volume, vibrato and panning.
Control Voltage – Control voltages (also called CVs) are used in analog synthesizers to affect changes in the
sound. In the case of pitch, pressing a key on the keyboard sends a control voltage that determines the
pitch of the oscillators. The keyboard CV is set to produce an equal tempered scale. As you play up the
keyboard, the CV is raised and the pitch increases. The pitch can also be affected by other CV sources,
like an LFO, often used to produce vibrato. Other major synthesizer components that respond to CV’s
include the lter (the higher the CV, the higher the lter cutoff frequency) and the amplier (the higher
the CV, the higher the gain, or volume).
Envelope – An envelope describes the contours that affect the characteristics of a sound (pitch, tone and
volume) over time. For example, when a string is plucked, its amplitude is suddenly very loud, but then
dies out gradually. This describes the Volume envelope of the sound. We observe that the initial part of
the plucked sound is very bright, but then the brightness fades away. This describes the Tonal envelope
contour. We also hear the frequency of the sound go slightly higher when the string is plucked, and then
drop slightly as the note fades. This is the pitch envelope contour. A synthesizer can create these kinds
of changes by applying electrically generated envelopes to oscillators (affecting pitch), lters (affecting
tone) and ampliers (affecting volume).
Envelope Generator – A circuit that generates an envelope signal. The envelope generator creates a time-
varying control voltage that can be applied to any voltage controlled circuit. The Taurus 3 features two
envelop generators: a Volume Envelope Generator with three adjustable parameters (Attack, Sustain
and Decay), and a Filter Envelope Generator with two adjustable parameters (Attack and Decay).
‘Attack’ and ‘Decay’ are specied as time parameters, while ‘Sustain’ is a level setting. Attack species
the onset time of the envelope. For example, the sound of a plucked string starts suddenly, meaning
its volume envelope has a fast attack time. Sustain is the level at which the envelope sustains after the
initial transient (the attack portion). Decay species how long the envelope takes to fade away. An En-
velope Generator uses a trigger to start and stop the envelope. This trigger is called a Gate signal, and
it’s produced whenever a footpedal is pressed. The gate signal turns on and stays on as long as a pedal
is held down; when the pedal is released, the gate signal turns off. When the gate turns on, the Envelope
Generator is triggered and the envelope signal moves through the Attack segment. For the Volume
envelope, the CV settles at the Sustain level as long as the gate signal is on. When the gate goes off,
the envelope goes through the Decay segment if the T3’s DECAY footswitch is ON. If the DECAY
footswitch is OFF, however, the envelope release time is instantaneous. For the Filter envelope, the CV
simply moves through the Attack and Decay segments.