DOEPFER Dark Energy - VCA Module Description

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Dark EnerGy
DOEPFER
Functionality
Whenusinganexternalaudiosignalpleasenote:TodisabletheVCO,putthewaveformswitchto„off“
(centerposition),movethePW-knobinfullyclockwiseorcounterclockwisepositionandshutoffPWMby
turningthePWMknobintofullycounterclockwiseposition.Tomakeaconnectedaudiosignalaudible,Dark
Energy‘sVCAhastobeopened.CrankuptheVCAknoband/orplayanoteonyourkeyboard,whichwill
open up the VCA via gate signal and ADSR control voltage. Of course you can use the external input and
theVCOinparallel.SoyoumayaddasecondVCO(e.g.DoepferA-110,controlledbytheCV1socket)
oranoisegenerator(e.g.DoepferA-117orA-118)asanadditionalsoundsource.
3.2.3. VCA
The VCA provides dynamic control over a third importand parameter – the loudness. A VCA is a voltage
controlledamplier.DarkEnergy‘sVCAissomewhatspecial:It‘scharacteristicsareexponentialfrom
approx.–90dBto–20dBandlinearbetween–20dBand0dB.Thisresultsinadifferentandmusically
moreusefulbehaviourcomparedtoordinaryVCAs.
TheVCAprovidesthefollowingcontrols:
•Amplitudeknob
ThisknobcontrolstheleveloftheoutputsignalinitiallyindependentfromtheADSR/
LFO1controls.Ifonlythisknobiscrankedup,youwillhearastatictone,notyet
inuencedbytheenvelopeorLFO1settings.
•AMknob(amplitudemodulation)
Thisknobadjuststheloudnessmodulationdepthofaselectedmodulationsource
(LFO1orenvelope/ADSR).Pleasenote:Abovethecenterpositionthemodulation
dephtdecreasesagain.Thehighestoutputlevelwithmaximumdynamicscanbe
achieved in settings around the center position. The reason for this effect is: The
maximumamplicationoftheVCAisfactor„1“.TheAMknobvalueisaddedtothe
amplitudeknobvalue.Ifthesumofthecontrolvoltagesbecomesgreaterthen„1“,
theyget„compressed“or„attened“.Thisresultsinanewanddifferentenvelope-or
LFOshapewithreduceddynamicsand–ifLFO1isselectedasmodulationsource
andAMknobissetabove7-8–inatrapezoidshapedvoltagecontour.Toachievea
symmetricalLFOmodulation,theamplitudeknobshouldbearounditscentersetting.
So,nexttothemodulationintensity,theVCAknobscanalsobe„abused“toshapethe
modulationcurve to a certain degree.
•AMSourceswitch
ThisswitchselectsthesourcefortheamplitudemodulationoftheVCA.TheswitchtogglesbetweenLFO1,
envelope(ADSR)andnosource(off).TheADSRasAMsourceprovidesa„oneshot“loudnesscontour.
Thismodulation–youmayremembertheltersection–isoneofthemostimportandstandartsinsound-
synthesis,sinceitsimulatesthetypicalcharacteristicsoftheloudnesscontourofacousticinstrumentsfrom
loudtosoft.LFO1againgeneratesperiodicmodulations.LowLFO1frequencysettingswillresultintremoli.
IfLFO1runsintheaudiorange(high),AMgeneratesnoisytextures.
•VCAAInput
ThissocketprovidesaninputforexternalCVstocontroltheVCAamplitude.Thissocketisnormalised,that
means that a plug disconnects the ADSR or LFO1 from the VCA control input in place of the external CV.
ThemodulationdepthisagaincontrolledwiththeAMknob.Thisinputprocessessignallevelsbetween0
Voltand+5Volt.
Again,thisCVisaddedtotheinternalCVprovidedbytheAMknob.
•AudioOutput
HereyoucanpickupDarkEnergy‘soutputsignal.Maximumlevelisapprox.1Vpp.