DOEPFER Dark Energy - VCO Module Description

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Dark EnerGy
DOEPFER
Functionality
3.2. The Modules
3.2.1. VCO
TheVCO,oralternativelytheexternalaudioinput,isthesourceofDarkEnergy‘s„raw“soundmaterial.The
VCOprovidesthebasicwaveformstriangle,sawtoothandsquarewithvariablepulswidth.Themodulehas
modulationinputsforfrequency(pitch)andpulswidth.Thefrequencyrangecoversapprox.10Hzto
12kHz.
TheVCOprovidesthefollowingcontrols:
•Manualtuningknob
Thisknobisusedforsharporatnetuningofthepitch.Aninternaljumperselectsthe
rangebetweenapprox.+/-1/2octaveor+/-2,5octaves.Thedefaultsettingis+/-1/2
octave.
•Rangeswitch-1/0/+1octave
Thisswitchselectsthetuningrange.
•FM(frequencymodulation)knob
ThisknobislocatedinthepitchcontrolinputoftheVCO.Itadjuststhepitchmodulati-
ondepthofaselectedmodulationsource(LFO1orenvelope/ADSR).Thisknobuses
anexponentialcharacteristictoachiveahigherresolutioninthelowerpitchrange.
•FMSourceswitch
ThisswitchselectsthefrequencymodulationsourceoftheVCO.Thechoicesare
LFO1,envelope(ADSR)ornosource(off).TheADSRgeneratesan„oneshot“pitch
contour,whichischaracteristicfore.g.certaindrum-andpercussion-sounds.LFO1
formsaperiodicandcontinousmodulation.LowLFO1frequencysettingswillresultin
vibrati.IfLFO1runsintheaudiorange(high),theVCOgeneratesverynoisytextures.
•ManualPulswidthknob
Thisknobchangesthepulswidthofthesquaresignal.Alteringthesymetryofthe
waveformfromsquaretosharppeakschangesit‘sharmoniccontentandthusthe
timbreofthesignal.Incenterposition,theVCOprovidesarectangular(square)signal
(a).Turningclockwiseresp.counterclockwiserstnarrowsthepulsesuntil,atit‘sextre-
mepositions,theVCOstoppsoscillatingandnopulswavesignalisaudible.
•PWM(Pulswidthmodulation)knob
Modulatingthepulswidthprovidesveryinterestingtextures.Thisknobislocatedinthepulswidthcontrol
input of the VCO.
Itadjuststhepulswidthmodulationdepthoftheselectedmodulationsource(LFO2orenvelope/ADSR).
Withhighmodulationdepthsand/ornarrowpulswidthsettings(manualpulswidthknobclosetofullyclock-
wise/fullycounterclockwise),themodulationdepthmightexceedthemaximumvalueofthepulswidth
rangeandthewaveformwillbreakdown.Asaresult,youwillheardropoutsintheaudiosignal.Thisis
normalandcanbeusedcreativelyasaninteresting„gate“-likeeffekt.
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a
b
c