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vactrol

Envelope follower unit generator emmulating a Perkin Elmer Vactrole VTL5C3/2.

Plugin opcode in buchla

Syntax

ares vactrol asig [iup, idown]

Initialisation

iup -- The rise time of the filter, which defaults to 20,

idown -- The fall time of the filter, which defaults to 3000,

Performance

asig -- The signal from which to extract the envelope.

Examples

Here is an example of the vactrol opcode. It uses the file vactrol.csd.

Example of the vactrol opcode.
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<CsoundSynthesizer>
<CsOptions>
 -odac
</CsOptions>
<CsInstruments>
    nchnls = 2
    0dbfs = 1

instr 1
    a1 lfo     0.3, 1, 4
    a2 vactrol a1
    a3 oscili  2, 440
       out     a1*a3,a2*a3
endin

</CsInstruments>
<CsScore>
    i1 0 3
    e
</CsScore>
</CsoundSynthesizer>

This opcode can reduce zipper noise produced from complex envelope tracking as it smooths the transitions.

See also

Sensing and Control: Envelope followers

Credits

Author: John ffitch
after Julian Parker
New in 6.04