Moog Music Minimoog Voyager XL - Manual (Page 22)

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Voyager XL User’s Manual - The Components
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Voyager XL User’s Manual - The Components
D. The Envelopes Section
Musical sounds have a start, middle and an end. For example, a plucked string sound starts with an initial
burst of energy and then slowly fades out until it is silent. In synthesis terms, this progression is called an
envelope – a shape that defines the changes that occur in a sound over time. An envelope can define any
aspect of change in a sound – volume, timbre, or pitch. The circuits that create envelope control signals in
synthesizers are called Envelope Generators (EGs).
When triggered, EG’s produce a time-varying control voltage that has a spe-
cific start, middle and end profile. The parameters that define this CV profile
are Attack, Decay, Sustain and Release, sometimes abbreviated as ADSR.
Attack determines the character of the onset of the sound. The EG’s
ATTACK knob controls this parameter by adjusting the time it takes for the
envelope to go from zero to full value (in other words, the fade-in time).
The DECAY control adjusts the second stage in the envelope’s evolution by
determining the time that it takes for the signal to drop from the full level to
the level set by the SUSTAIN control. The envelope will remain at the Sustain
level as long as an envelope gate signal is present (i.e. a key is held down).
When the gate signal is released, the
RELEASE control determines the time it
takes for the envelope to transition from
the Sustain level to zero (see the ADSR
Envelope Signal figure).
The Voyager XL has two identical EG circuits; one EG is dedicated to the filter (to control the cutoff fre-
quency), and one is EG dedicated to the amplifier (to control the volume). Both EG’s can also be used as
a modulation sources or modulation shaping through the Modulation Busses, and both EG’s are available as
individual CV Outputs on the Patch Panel.
Filter CV Inputs on the Patch Panel:
CUTOFF -
The CUTOFF jack allows you to connect an external CV or expression pedal to control the filter cutoff
frequency. Both filters are effected by this connection, regardless of the filter mode setting. The effective
input range is -5 to +5 V, where a positive CV will add to the filter cutoff knob setting, and a negative CV
will subtract from the setting. Note that if an Expression Pedal is plugged into this jack, the cutoff can only
be made to increase from the cutoff dial setting since the pedal connection supplies only a positive voltage.
Although CV Inputs for Filter Spacing and Resonance are not available on the Patch Panel, there are ways
to externally control these parameters. Filter Spacing can be selected as a Programmable Modulation
Destination in either Mod Bus, thus you could route the MOD2 input to control Filter Spacing through the
Mod Busses. Also, MOD1 or MOD 2 inputs may be routed using the POT MAPPING feature to control any
of the front panel knob functions, including Filter Spacing or Resonance.