vactrol

vactrol — Envelope follower unit generator.

Description

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

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 1040. Example of the vactrol opcode.

See the sections Real-time Audio and Command Line Flags for more information on using command line flags.

<CsoundSynthesizer>

<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.

Credits

Author: John ffitch
after Julian Parker
New in 6.04