Kurzweil PC3K Series - VAST Program Structure

6-2
Program Mode
VAST Program Structure
VAST Program Structure
YoumightwanttotakealookatFigure 6‐1onpage6‐3,whichdepictsthehierarchyofaVAST
program,fromindividualsamplesallthewayuptosetups,whichcancontainupto16
programs.
EveryVASTprogramcontainsatleastonelayer.Alayerconsistsofakeymapandan
algorithm
forprocessingthesamplescontainedinthekeymap.Eachsampleisaseparatedigitalrecording
ofsomekindofsound:musical,vocal,industrial,anysoundatall.Individualsamplesare
assignedtospecifickeyranges(fromA2toD3,forexample),andarealsoassignedtobe
triggered
atspecificattackvelocities.Theseassignmentsconstitutethekeymap.
Whenyoutriggeranote,thePC3 Klookstothekeymapofeachlayerofthecurrentlyactive
VASTprogram(s)todeterminewhichsamplestoplay.Thesoundenginethenfetchesthe
requestedsamplesandgeneratesadigitalsignalrepresentingthesound
ofthesamples.This
signalfirstpassesthroughtheDSPfunctionsthatmakeupthealgorithm.Itthenpassesthrough
thePC3K’seffectsprocessor,andfinallyappears—withsomelevelofeffectsappliedtoit—at
oneormoreoftheaudiooutputs.
ThelayeristheVASTprogram’sbasicunitofpolyphony,
thatis,eachlayerconstitutesoneofthe
128voicechannelsthePC3Kcanactivateatanytime.Ifyouhaveaprogramthatconsistsoftwo
layerscoveringthenoterangefromA0toC8,eachkeyyoustriketriggerstwovoicechannels.
Note:Oneexceptiontothis
structureiswhenusingaKVAoscillator,thesoundsourceforthatlayeris
notderivedfromakeymap,butisgeneratedatthealgorithmstage(thoughkeymapinformationisstill
usedtosetkeyrangeandmaximumamplitude.)Afterthis,thestructureisthesameasdescribedabove.
See
EditingVA S T ProgramsWithKVAOscillators on page 6‐53formoredetails.