DOEPFER Dark Energy User manual

Dark Energy
Owners Manual
DOEPFER MUSIKELEKTRONIK GmbH

2
Safety Instructions
Please follow the instructions for use of the instrument carefully because this will guarantee
proper operation of the instrument. Due to the fact that these instructions touch on Product Liability, it is
absolutely imperative that they be read carefully. Any claim for defect will be rejected if one or more
of the items has not been observed.
Disregard of the instructions can void the two years covered by warranty.
The instrument may only be operated at the voltage stated on the power input on the rear panel. Before
opening the case, disconnect both power plug and power adaptor.
All eventual modications are to be performed by a qualied person only in accordance with valid safety
instructions. With the introduction of a third person, the warranty will be void. In case of a destroyed
warranty seal, any warranty claim will be rejected.
The instrument must never be operated outdoors but solely in dry rooms. Never use the instrument in a
humid or wet environment, nor near ammable goods.
No liquids or conducting substances must get into the instrument. Should this be the case, the instrument
is to be disconnected from mains power immediately and examined, cleaned and possibly repaired by a
qualied technician.
Never expose the instrument to temperatures above +50° C or below -10° C. Before operation, the
instrument should have a temperature of at least 10°C. Do not expose the instrument to direct sunlight.
Do not install the instrument near heat sources like heaters, open re places, central heating etc.
Keep the top of the instrument clear in order to allow proper ventilation, otherwise the instrument
could eventually overheat.
Never place heavy objects on the instrument.
Transport the instrument carefully, never let it drop or fall over. Make sure that during transport and in use
the instrument is supported properly and cannot drop, slip or fall over because people might get injured.
Never use the instrument in the immediate proximity of electronic devices (e.g. monitors, power
supplies, computers) as these interferences could cause malfunctions within Dark Energy and corrupt
memory data.
The instrument is to be shipped in the original packaging only. Any instrument shipped to us for return,
exchange, warranty repair, update or examination has to be in its original packaging! All other deliveries
will be rejected. Therefore, make sure you keep the original packaging and technical documentation.
The instrument may only be used for the purpose described in this operating manual. Due to safety
reasons, the instrument must never be used for other purposes.
When using the instrument in Germany, the appropriate VDE standards are to be followed. The following
standards are of special importance: DIN VDE 0100 (Teil 300/11.85, Teil 410/11.83, Teil 481/10.87), DIN
VDE 0532 (Teil 1/03.82), DIN VDE 0550 (Teil 1/12.69), DIN VDE 0551 (05.72), DIN VDE 0551e (06.75),
DIN VDE 0700 (Teil 1/02.81, Teil 207/10.82), DIN VDE 0711 (Teil 500/10.89), DIN VDE 0860 (05.89), DIN
VDE 0869 (01.85). VDE papers can be obtained from the VDE-Verlag GmbH, Berlin.

3
Content:
1. Introduction
1.1. Preface………………………….... 4
1.2. Preparations……………………... 5
1.3. Check it out………………………. 6
2. Overview……………………………………. 8
3. Functions
3.1. Signal path……………………… 10
3.2. The Modules
3.2.1. VCO……………………... 12
3.2.2. VCF………………………..14
3.2.3. VCA………………………. 16
3.2.4. ADSR…………………….. 17
3.2.5. LFO1 and LFO2…………18
3.3. USB/MIDI Interface
3.3.1. Connection /
MIDI Channel……………. 19
3.3.2. MIDI to CV Interface……. 20
3.3.3. Learn-Mode /
MIDI-Functions………...... 21
3.3.4. Reset…………………….. 24
DOEPFER
Dark Energy
Owners Manual
3.4. Linking / Stacking of several
Dark Energies…………………… 25
 3.5.Modications……………………..25
3.6. Firmware Update ……………..... 25
4. Nuts and Bolts of
Soundgeneration………………………… 26
5. An ample sample of
sound examples…………………………. 31
6. Addendum
Service and Terms
of Warranty………………………….. 43
Imprint.…….……………………..…...43

4
Dark EnerGy
DOEPFER Introduction
1. Introduction
1.1. Preface
Welcome to Dark Energy. As you might have guessed already, your newly purchased Dark Energy is not a
toolforspaceresearch,neitherisitsuitableforstudiesinastrophysics.Yet,wendthesetopicsasfasci-
nating as music technology - reason enough to celebrate Hubble & Co‘s amazing discoveries a bit and call
our brand-new synthesizer Dark Energy.
Doepfer says „thank you!“
First of all we would like to thank you for purchasing Dark Energy! We really appreciate your choice and
promise you an extraordinary support throughout, including useful information, easy service, and innovative
product development.
May your Dark Energy be an important source of creative power for ages to come.
What‘s this?
Dark Energy is a monophonic, analog synthesizer with USB and MIDI interface. Its entire sound generation
as well as all its modulation sources is 100% analog. Only the USB/MIDI interface uses, of course, digital
component parts.
Dark Energy is housed in a rugged black sheet metal case with wooden side panels. Only high-quality
potentiometers (referred to as „pot“, in case you should be wondering where the „weed“ is…) with metal
shaftshavebeenused.Eachpothasbeenmountedrmlytothechassis.Thespacebetweentheknobsis
wider than e. g. on the A-100 modular system, and we made use of knobs which have a classy vintage look
to them. Dark Energy looks as beautiful as it sounds and is made for extensive live tweaking sessions. You
will get all the advantages of analog sound generation as well as direct access to all crucial parameters -
forget about confusing menus and tiny displays. Yet, Dark Energy is a modern tool for sound creation and,
thanks to its built-in MIDI/USB interface, can easily be linked with every modern computer-based studio or
live-setup. Hooking Dark Energy up to classic vintage analog equipment or to a Doepfer A-100 modular
system is also easy.
R.t.f.m.!
Weknewit:Usermanualsareyourrstchoiceinliterature.Hey,that´sgreat–we´retalkingthesame
languagehere!Ifyouareindoubtabouttheentertainingqualitiesofthismanual–howdareyou!–,please
bear in mind that its thorough study will eventually turn out to be quite useful, as it will highly increase the
entertaining qualities of your new synthesizer as well. So please do yourself - and us - a big favor: Read
(andpossiblyunderstand)thisfriggin´manual!Blessyouforyourefforts!
IntherstsectionyouwillndallinformationneededtohookupDarkEnergytoyoursetup.
Afterthat,youwillndabriefoverviewofitsfunctions.Synthesizerexpertsmayusethisasaquickstart
guide. You should not skip the complete description of the entire „functions“ section in the next chapter,
though-DarkEnergyhidessomeinterestingfeatures.Apartfromthat,youwillndusefultemplatesfor
some patching. If synthesizer technology and the secrets of subtractive synthesis are totally new to you,
please refer to „Nuts and bolts of sound generation“ later on in this manual.
Enough talk - here we go...

5
Introduction
Dark EnerGy
DOEPFER
1.2. Getting started
WhenyouliftDarkEnergyoutofitsboxforthersttime,pleasemakesurethateverythingisinitsright
place.Youwillndthefollowingcomponentpartsinthebox:
•DarkEnergySynthesizer
•wall-wart(15VAC/400mA)
•instrumentcablewith1/8“and1/4“plugs
•USBcable(A-Btype)
•twoA-100patchcables
•thisowners´manual
You will also need:
•Asuitableaudiosystem(mixer,amplier,speaker,orkeyboardamp)
To run Dark Energy via its MIDI-DIN socket, you will also need:
•AMIDIcabletoconnectasuitableMIDIcontrollingdevice/keyboard/computertoDarkEnergy.
•AMIDI-keyboardand/orcomputerwithsuitableMIDIsequencerapplication
To run Dark Energy via its CV/Gate inputs, you will also need:
•Atleasttwo1/8“plugpatchcables–themore,thebetter–andasuitablesequencer(e.g.theDoepfer
sequencer module A-155) or a CV/Gate keyboard (e.g. the Doepfer model A-100).
Setup:
UseDarkEnergyinaatoruprightposition.Pleaseuseasuitablesupport.Thewoodensidepanelscan
be removed in order to link up two or more units mechanically to make one big device. More information on
this topic can be found later on in this manual.
Connections:
To run Dark Energy, you do not necessarily need all its built-in sockets. For a basic setup, you will need
just the ones pictured below. Make use of the additional connection terminals and you will expand Dark
Energy‘s sonic potential a great deal. These connectors will be described along with the corresponding
modules later on in this manual.
Tune
Res
ADSR
Range
Shape Shape
Shape
Range
Range
LFO1 LFO2 LFO1
LFO2
up half low
high
highhigh
low
low
ADSR ADSR ADSR
ADSR
down full medium
Attack
Decay
Sustain
Release
medium
medium
Frequ.
Frequ.
Inputs Outputs
GateVCA AVCF FVCO PWVCO F Ext.
Audio LFO1 Envelope Audio
VCO VCF Envelope
VCA
LFO1
LFO2
o o
o
o
o
o
o
o
Frequ. Amp
AMXFMFM
PW
PWM
LFM
Octave
Source Source Source
Source
Track
DARK ENERGY DOEPFER
0
4
5
1
3
2
10
9
7
8
0
4
5
1
3
2
10
9
7
0
4
5
1
3
2
10
9
7
0
4
5
1
3
2
10
9
7
0
4
5
1
3
10
9
7
0
4
5
1
3
10
9
7
0
4
5
1
3
10
9
7
8
0
4
5
1
3
10
9
7
8
0
4
1
3
10
9
7
8
0
4
5
1
3
10
9
7
8
0
4
1
3
10
9
7
8
0
4
1
3
10
9
7
8
0
1
3
2
10
9
8
0
4
1
3
2
10
6
9
7
8
0
4
1
3
2
10
6
9
7
8
0
4
1
3
2
10
6
9
7
8
Amp or Mixer
MIDI Out
MIDI In
15V AC
400mA
Instrument-
Cabel with
1/4“-Plug
Computer
with
Software-Sequencer
USB
USB
MIDI-Keyboard / Sequencer
Power-
Adaptor
Wall-Outlet

6
Dark EnerGy
DOEPFER Introduction
•Powersupply:
Connect the included power adaptor („wall wart“) with the 15V AC socket on the rear panel of Dark Energy.
Important: Use this power adaptor only or an equivalent one with exactly the same specs!
A power supply via USB is not possible since the internal analog circuits of Dark Energy run at +/-12V. If
two or more units are running in parallel, each unit needs its own power supply with wall wart. Should need
and demand be, we might take offering a bigger wall wart with several power outlets into consideration.
•USB:
ConnectDarkEnergy‘sUSBsocketwithyourcomputer.Anycongurationworkordriverinstallationisnot
required.
•MIDI:
To run Dark Energy in a conventional MIDI setup without USB, please connect Dark Energy‘s MIDI-in so-
cket with the MIDI-out socket of your MIDI controller device (e.g. master keyboard, synthesizer, sequencer).
The default setting of Dark Energy‘s MIDI channel is Channel 1. How to change this setting is described on
page 19 in the chapter „USB/MIDI interface“.
•Audio:
Connect the „Audio“ output on Dark Energy‘s front panel with the audio input of your mixer, amp, etc.
Please use the connection cable included.
•CV/Gate:
When controlling Dark Energy from a CV/Gate sequencer / keyboard, you have to connect at least Gate-
and VCO F jacks. Gate triggers the notes, VCO F determines the pitch of the notes. Using additional VCO
PW, VCF F and VCA A connections, Dark Energy‘s corresponding sound parameters can be controlled
dynamically via control voltages. More on this topic later on in this manual.
1.3. Check it out
Please set all frontpanel controls to their initial settings as pictured below. The default MIDI
channel setting is # 1 and should not be touched at this point.
Tune
Res
ADSR
Range
Shape Shape
Shape
Range
Range
LFO1 LFO2 LFO1
LFO2
up half low
high
highhigh
low
low
ADSR ADSR ADSR
ADSR
down full medium
Attack
Decay
Sustain
Release
medium
medium
Frequ.
Frequ.
Inputs Outputs
GateVCA AVCF FVCO PWVCO F Ext.
Audio LFO1 Envelope Audio
VCO VCF Envelope
VCA
LFO1
LFO2
o o
o
o
o
o
o
o
Frequ. Amp
AMXFMFM
PW
PWM
LFM
Octave
Source Source Source
Source
Track
DARK ENERGY DOEPFER
0
4
5
1
3
2
10
9
7
8
0
4
5
1
3
2
10
9
7
0
4
5
1
3
2
10
9
7
0
4
5
1
3
2
10
9
7
0
4
5
1
3
10
9
7
0
4
5
1
3
10
9
7
0
4
5
1
3
10
9
7
8
0
4
5
1
3
10
9
7
8
0
4
1
3
10
9
7
8
0
4
5
1
3
10
9
7
8
0
4
1
3
10
9
7
8
0
4
1
3
10
9
7
8
0
1
3
2
10
9
8
0
4
1
3
2
10
6
9
7
8
0
4
1
3
2
10
6
9
7
8
0
4
1
3
2
10
6
9
7
8

7
Introduction
Dark EnerGy
DOEPFER
As soon as the power adaptor has been plugged in, Dark Energy will power up. The LEDs in both LFO
sectionswillnowlightupandalternatebetweenredandgreen.TheLEDonthebackpanelwillashinter-
mittently for about two seconds and then stay lit permanently.
First contact:
Turn the volume control of your amp / mixer fully off BEFORE powering Dark Energy up. Turn up the vo-
lume control of your mixer / amp slowly and play a key on your keyboard. You ought to hear a steady tone
now.Chooseacomfortablevolume.Andnow-LadiesandGentlemen,we´reoatinginspace:
Welcome to Dark Energy!
The sound currently generated depends on the setting of all knobs and switches. It will be the easiest to
create musically useful patches if you start with this basic setting and „compose“ your sounds step by step
from that point onwards.
We will now have a brief look at Dark Energy‘s sound generation and sound-modelling modules.
A detailed description of all functions will follow later on.
Now that you have tweaked all knobs and switches to their initial settings, you will hear a simple and steady
tone.
The oscillator generates a simple square wave that is audible at the audio output, yet without being modi-
edinanyway.NowturntheVCOtunecontrolandmovetheoctaveswitch:Youcancontrolthetuningand
the pitch range of the tone.
As soon as you crank up the FM control, you will notice an „automatic“ change in tuning: LFO1 is selected
as a modulation source and its control voltage generates a periodic change in tuning or VCO frequency
respectively.
Now turn the „LFO1 Freq.“ control. You will hear a change in the modulation speed or LFO1 frequency
respectively.
Nowlet‘shaveabrieflookattheltersection(VCF):Turnits„Freq.“potslowlycounter-clockwise.Youwill
hear the sound becoming gradually „duller“ until it becomes inaudible. Now turn the „Freq.“ pot to 12 o‘clock
position and crank up the XM control slowly. You will hear a periodic modulation of the timbre by LFO2.
Again, you can alter the modulation speed using the LFO2 Freq. pot. Play a couple of keys and change the
settings of the envelope section. You will notice a change in the loudness contour of the notes. When you
turn the „Source“ switches in the VCO and VCF section to the „ADSR“ position (the knobs FM and XM have
to be cranked up to at least 10 o‘clock position), the envelope will control not only loudness but also pitch
and timbre.
Please note:
Dark Energy‘s parameters mostly interact with each other in some way or other. That means, there is often
morethanjustonewaytoachieveaspecicresult.Inotherwords:Ifyouwantacertainparametertogene-
rateadesiredresult,itmightbenecessarytosetotherparameterstoanotherspecicvalue.Thismightbe
a bit confusing from time to time. An example:
If the ADSR‘s sustain knob is at its maximum, turning the decay knob will not have
any effect on the sound. All ADSR controls will not have any effect on the timbre of a patch as
long as the „Source“ switch of the VCF section is set to LFO2. The same goes for the „Source“ switch in the
VCA section.
If you really want to make use of Dark Energy‘s full sonic potential, it is important to understand the way the
parameters interact with each other. Please do not panic - explore systematically each parameter and its
interactionwithothers.There´snothingyoucouldblowup,andnormalitywillberestoredsoonifsomething
seems weird to you.
If analog subtractive sound synthesis is totally new to you, please refer to the section „Nuts and bolts of
sound generation“ in this manual.

8
Dark EnerGy
DOEPFER Overview
2. Overiew
The layout of Dark Energy is that of a classic monophonic modular synthesizer. Its signal path is hard-wired
internally, thus Dark Energy is very compact and easy to use. The most important modulation routings can
be set via toggle switches, additional sockets take or deliver control voltages and allow the connection with
external modulation sources. The internal MIDI/USB interface makes easy use within a MIDI setup possib-
le. Dark Energy can also be used as a MIDI-to-CV/Gate interface. Wow!
Tune
Res
ADSR
Range
Shape Shape
Shape
Range
Range
LFO1 LFO2 LFO1
LFO2
up half low
high
high
high
low
low
ADSR ADSR ADSR
ADSR
down full medium
Attack
Decay
Sustain
Release
medium
medium
Frequ.
Frequ.
Inputs Outputs
GateVCA AVCF FVCO PWVCO F Ext.
Audio LFO1 Envelope Audio
VCO VCF Envelope
VCA
LFO1
LFO2
o o
o
o
o
o
o
o
Frequ. Amp
AMXFMFM
PW
PWM
LFM
Octave
Source Source Source
Source
Track
DARK ENERGY DOEPFER
0
4
5
1
3
2
10
9
7
8
0
4
5
1
3
2
10
9
7
0
4
5
1
3
2
10
9
7
0
4
5
1
3
2
10
9
7
0
4
5
1
3
10
9
7
0
4
5
1
3
10
9
7
0
4
5
1
3
10
9
7
8
0
4
5
1
3
10
9
7
8
0
4
1
3
10
9
7
8
0
4
5
1
3
10
9
7
8
0
4
1
3
10
9
7
8
0
4
1
3
10
9
7
8
0
1
3
2
10
9
8
0
4
1
3
2
10
6
9
7
8
0
4
1
3
2
10
6
9
7
8
0
4
1
3
2
10
6
9
7
8
triangle waveform based VCO
- tuning knob
- range switch -1 / 0 / +1 octave
- FM (frequency modulation) knob with selectable
modulationsource (LFO1 / off / ADSR)
- pulswidth knob for squarewave
- PWM (pulswidth modulation) knob with selectable
modulationsource (LFO1 / off / ADSR)
- waveform switch (saw / off / triangle)
The sum of the squarewave signal and the waveform
selected with the waveform switch is fed into the audio
in of the filter module (to disable the squarewave both
PW- and PWM-knobs have to be turned fully counter-
clockwise).
VCO CV inputs
- VCO frequency (1V/octave)
- pulswidth of squarewave
24 dB lowpass VCF
- cutoff knob (freq.)
- tracking switch half / off / full
(internally connected to the VCO control
voltage)
- XM: exponential frequency modulation
knob with selectable modulationsource
(LFO1 / off / ADSR)
- LM: linear frequency modulation knob;
modulationsource is the VCO‘s
trianglewave (resp. the VCF gets linear
FM from the VCO with adjustable
intensity)
- resonance knob (up to selfoscillation)
audio input
(the connected signal is
mixed into the VCF input)
VCF CV input
- VCF frequency (1V/octave)
VCA
- amplitude knob
- AM (amplitude modulation) knob
with selectable modulationsource
(LFO1 / off / ADSR)
VCA CV input
- VCA amplitude
LFO1 and LFO2
- frequency knobs
- waveform switches (triangle / off /
square)
- range switches: low (up to several
minutes per cycle) / audio (up to
5 kHz) / medium (normal LFO range
from some seconds up to several
10th hertz)
- dual LEDs yellow/red show positive
and negative halfs of the LFO waves
LFO1 CV output
(inverted)
ADSR
- knobs for Attack,
Decay, Sustain and
Release
- range switch long / short /
medium
- blue LED for envelope
activity
ADSR CV output
gate input
audio output

9
Overview
Dark EnerGy
DOEPFER
CV1 Gate Learn Midi In USBCV2
Outputs
CV3CV4400mA
(Audio Out)15V AC
DARK ENERGY
ANALOG SYNTHESIZER
DOEPFER
powersupply
(15VAC, 400mA)
CV outputs
CV1: controlled by MIDI note messages, 1V/octave, 0...+5V
(internally routed to the VCO frequency input)
CV2: controlled by MIDI pitchbend data (centered approx.
-2,5...+2,5V or positive 0...+5V, userselectable via internal
jumper, no fixed internal routing; can be connected via patchcord
with e.g. the control voltage input of the VCO or VCF)
CV3: controlled by MIDI velocity data (0...+5V, no fixed internal
routing; can be connected via patchcord with e.g. the control
voltage input of the VCF or VCA)
CV4: controlled by MIDI control change messages, learn mode
for setting of controller number (0...+5V, no fixed internal routing;
can be connected via patchcord with e.g. the control voltage
input of the VCF or pulswidth input of the VCO)
gate output
(with LED, also for learn
function), 0/+5V
Learn button
MIDI input
USB
(for MIDI via USB)

10
Dark EnerGy
DOEPFER Functions
3. Functions
In this section, we will explore all of Dark Energy‘s modules and functions in detail. We will also have a
closerlookatthewaythemodulesinteract,andnallyatMIDI.
3.1. Signal path
USB
MIDI In
MIDI / CV
Interface
Oscillator
(VCO)
Filter
(VCF)
Amplifier
(VCA)
Low Frequency
Oszillator 2
(LFO1)
Low Frequency
Oszillator 2
(LFO2)
Envelope
Generator
(ADSR)
Audio
Output
Gate Signal
Envelope Control Voltage
LFO Control
Voltage
Pitch Control
Voltage
Audio Audio Audio
CV 4 CV 3 CV 2 CV 1
ThegureaboveillustratesanoverviewofDarkEnergy‘ssignalpath.
The dark-grey boxes show all modules that generate or process the sound (or the audio signal, respec-
tively.) They are labelled VCO, VCF, and VCA, and together they form the audio path.
The light-grey boxes are control modules. Instead of audio signals, they generate control voltages which
modulate the audio modules. The envelope generator can send control voltages to VCO, VCF, and VCA.
The low frequency oscillators (LFO1 and LFO2) can send their control voltages to both oscillators, to the
lter(LFO2),ortotheamplier(LFO1)respectively.
The MIDI-to-CV/Gate interface „translates“ incoming MIDI data into control voltages that can be tapped
fromthesocketslabelledCV1-4.CV1isalsofedintotheVCO´sinputtocontroltheoscillatorpitch.Apart
fromthat,theMIDI-to-CV/Gateinterfacegeneratesagatesignalwhichtriggerstheenvelopeandresoffa
tone.
Thegureonthefollowingpageshowsthecompletesignalpathinallitsbeauty.Ifyouareabittechnically
orientated,youwillnditeasytofollowthosetinyelectronsthroughthemazeofthecircuitry.Allinputsand
outputs,potsandswitchesaswellasallinternalsubmodules–suchasaddersandinverters–areshown
in the illustration.
The functions of all modules are described in detail in the following section from page 12 onwards. A more
general and easy-to-understand description of analog sound generation can be found in section 4, „Nuts
and bolts of sound generation“.

11
Dark EnerGy
DOEPFER Functions
VCO
LFO1 LFO2
Envelope
(ADSR)
VCF
Frequ. Frequ.
Release
Sustain
Decay
Attack
PW
Tune
Range
Range
Range
ShapeShape
up
low
low
low
high
high
high
medium
medium
medium
LFO2 LFO1
Exponential Frequency Control
Adder Adder adder
PWM
FM
off off
ADSR ADSR
Source Source
Gate
Shape
off
Outputs
Rectangle
Pulsewidth
Control
Section
Adder
down
tune
range
(JP4)
Resonance
Control
Section
Linear Frequency Control Resonance Control Audio In
Audio
Out
Inverter
Audio In
LFM
Res
VCO PW
VCO F
VCA A
VCA
Amp.
LFO1
amplitude control
AM
off
ADSR
Source
Ext.
Audio
Frequency
Control
Section
Frequency
Control
Section
Envelope
Out
Audio
Out
Audio Output
Miniature Jack Socket Rotary Control (Potentiometer)
LFO1 Output Envelope Output
Octave
USB/Midi Interface
USB Gate/
Learn
Miniature Jack Socket with Switching Contact LED Display
Toggle Switch Momentary Push Button Midi Socket
Midi In
link option
glide option
Learn
Gate
CV1 (Note)
CV2 (Pitch B.)
CV3 (Vol./Vel.)
CV2 (Ctr./Vel.) USB Socket
Internal Connector / Jumper
DOEPFER
Dark Energy
-1
(JP7)
(JP3)
(JP12)
(JP2)
(JP8)
Frequ.
LFO2
Adder
XFM
off
ADSR
Source
Track
off
full
half
1/2
VCF F

12
Dark EnerGy
DOEPFER Functions
3.2. The Modules
3.2.1. VCO
The VCO, or alternatively the external audio input, is the source of Dark Energy‘s sonic „crude material“.
The VCO produces the basic waveforms triangular, sawtooth, and square wave with variable pulsewidth.
The module has modulation inputs for frequency (pitch) and pulsewidth. The frequency range covers
approx. 10 Hz to 12 kHz.
The VCO has the following controls:
•Manualtuningcontrol
Thispotisusedforsharporatne-tuningofthepitch.Aninternaljumperselectsthe
range of the pot between approx. +/- 0.5 octave or +/- 2.5 octaves. The default setting
is +/- 0.5 octave.
•Rangeswitch-1/0/+1octave
This switch selects the tuning range.
•FM(frequencymodulation)control
This pot is located in the pitch control input section of the VCO. It adjusts the pitch mo-
dulationdepth of the selected modulation source (LFO1 or ADSR envelope). This pot
has exponential response to yield a higher resolution in the lower pitch range.
•FMSourceswitch
This switch selects the frequency modulation source of the VCO. The choices are
LFO1, envelope (ADSR), or no source at all (off). The ADSR generates a „one shot“
pitch contour, which is characteristic of e.g. certain drum- and percussion-sounds.
LFO1 produces a periodic and continuous modulation. „Low“ frequency settings of
LFO1 will produce vibrato. If LFO1 runs at audio rate (high), the VCO will generate
quite noisy textures.
•ManualPulsewidthcontrol
This pot changes the pulsewidth of the square wave. Altering the symmetry of the
waveform from wide to narrow square alters its harmonic content and thus the
timbre of the signal. In center position, the VCO produces a rectangular (square) signal
(a).Turningclockwiseorcounter-clockwiserespectivelyrstnarrowsthepulsewidth
until, at its most extreme setting, the VCO stops oscillating and no pulse wave signal is
audible anymore.
•PWM(Pulsewidthmodulation)control
Modulating the pulsewidth creates very interesting textures. This pot is located in the pulsewidth control in-
put section of the VCO. It adjusts the pulsewidth modulation depth of the modulation source selected (LFO2
or ADSR envelope.) At high modulation depths and/or narrow pulsewidth settings (manual pulsewidth
control close to fully clockwise / fully counter-clockwise), the modulation depth might exceed the maximum
value of the pulsewidth range and the waveform will become inaudible. As a result, you will hear drop-outs
in the audio signal. This is perfectly normal and can be used creatively as an interesting „gate“-like effect.
f/1f/1
ab
c

13
Dark EnerGy
DOEPFER Functions
•PWMSourceswitch
This switch selects the source of the square wave‘s pulsewidth modulation. The switch toggles between
LFO2, envelope (ADSR), and no source (off). The ADSR generates a „one shot“ pulsewidth modulation,
LFO2 produces a periodic and continuous modulation. „Low“ LFO2 frequency settings will result in „spaci-
ous“ and „lush“ textures which are very useful for huge pad sounds. If LFO2 runs at audio frequency (high),
the VCO will generate noisy textures that will be quite different sonically from FM effects.
•Waveformswitch(saw/off/triangular)
Apart from the square wave, the VCO also generates triangular and sawtooth waves. The sum of the
squarewavesignalandthewaveform,selectedbythewaveformswitch,isfedintotheinputofthelter.To
disable the square wave, turn the PW-control fully clockwise or fully counter-clockwise and shut off PWM by
turning the PWM control fully counter-clockwise. Now only the sawtooth or triangular wave will be audible,
depending on the setting of the waveform switch.
To disable the VCO completely, set the waveform switch into off-position, turn the PW control fully clockwi-
se or counter-clockwise, and the PWM control fully counter-clockwise. Use this setting if, for example, you
wanttofeedanexternalaudiosignalintothelterofDarkEnergy.
•VCOFInput
Usually,theVCO´sinternalpitchCVinputisconnectedwiththeoutputCV1ofthebuilt-inMIDI/USBin-
terface. This VCO input uses the standard 1volt / octave scaling which is common with most other analog
synthesizers. This allows you to play Dark Energy just like any other keyboard instrument with tempered
tuning resp. tuned chromatically. You do not have to scale or tune anything.
In case you want to use Dark Enery without MIDI but connected to a CV/Gate sequencer or a Doepfer
A-100 modular synthesizer, you can make use of Dark Energy‘s CV inputs. The VCO F socket features an
externalCVinputforVCOfrequency(tuning).Assoonasyouplugacablein,theVCO´spitchisgoverned
by this input. Please bear in mind that this socket is not normalized. This means that the connection bet-
ween the MIDI/USB interface and the VCO will not be interrupted when a cable is plugged in. The external
CV will be added to the value produced by the MIDI/USB interface. This is very useful e.g. for transposing
a sequence which is played on an A-155 step sequencer to a different key in realtime, using a MIDI/USB
keyboard.
Instead of a CV/Gate sequencer or a keyboard, you may also use any other suitable CV or even audio
signals as a modulation source.
•VCOPWInput
If you wish to control the pulsewidth of the square wave using an external CV, use this input socket. A range
of 5 Volts covers the entire modulation range.
IfanexternalcontrolvoltagedoesnotcomplywiththespecicationsofDarkEnergy‘sCVinputs(VCOF,
VCO PW, VCF F, VCA A, ext. Audio) because it is too high or too low, please use an external attenuator
(e.g.DoepferA-183-1)oramplier(e.g.DoepferA-183-3).Theseadditionalmodulescaneasilybehoused
in a Doepfer A-100 Minicase.

14
Dark EnerGy
DOEPFER Functions
3.2.2. VCF
Filters are a very important tool on every analog synthesizer. Filters modify sounds by rejecting some fre-
quencies while allowing others to pass in order to tweak the harmonic spectrum of a sound.
Therearedifferenttypesoflters;themostcommonlyusedandmusicallymostusefulltertypeisthe24
dB„lowpass“,whichisusedinDarkEnergy.Asitsnamemightleadyoutothink,a„lowpass“lterletsall
frequencies below the so-called „cutoff frequency“ pass and rejects frequencies above the cutoff frequency.
This point can be controlled by a pot or modulated by a control voltage in order to achieve dynamic timbral
shifts.
Anotherimportantltertermis„resonance“.Filterresonanceemphasizestheharmonics
around the cutoff frequency point. The sound will become increasingly „sharper“ and „edgier“. At a certain
level,thelterwillstarttoself-oscillateandgenerateawaveformclosetoasinewave.DarkEnergy‘sVCF
can also be driven into self-oscillation in oder to use it as an additional signal source for certain popular
sound effects which are immediately recognizable as „typically synthesizer“.
The VCF gives you the following controls:
•Manualfrequencycontrol(Freq.)
This pot allows you to control the cutoff frequency of the VCF manually. In other
words,itisuptoyouto„open“and„shut“the„window“ofthelter.Turnedfullyclock-
wise,thelterwillbeopenedcompletelyandtheentirefrequencyrangeoftheinco-
mingsignalcanpass.Turnedfullycounter-clockwise,thelterwillbeclosedtoan
extent that all audible frequencies will be rejected and no output signal will be audible.
TheentirefrequencyrangeofDarkEnergy‘sltercoversapprox.12octaves.The
further this knob is turned clockwise, the lesser the effect of the envelope (ADSR) on
the sound will be.
•XMcontrol
In order to achieve dynamic and periodic changes of timbre, the cutoff frequency
can be modulated by control voltages. The XM knob determines the modulation
depth. Set fully counter-clockwise, no modulation will appear, while turned fully clock-
wise means maximum modulation depth. The modulation depth will be added to the
setting of the manual frequency knob. Since the sum of both cannot exceed the maxi-
mumvalueofthecutoffparameterrange,thesettingofthe„Freq.“potinuencesthe
modulation depth: The higher its set value, the less the effect of the XM knob on the
sound. The XM function uses exponential frequency modulation.
In some cases, FM has to be controlled and used in a very subtle way, especially
whenthelterisself-oscillating(thatis,workingasasinewaveoscillator)andmodu-
lated by LFO2 at audio rate. In order to optimize parameter scaling, the XM control
works in an exponential way. Thus, audible modulation might require settings above
„5“, especially when using the ADSR as a modulation source.
f
c
CV
tuOtuO
.qerF.qerF
f
c
Resonance changes the lter characteristics
f
c
Resonance
Frequency
0 db
Attenuation
Thecutofffrequencyofalowpasslter
depending on the control voltage
The resonance characteristics of a
lowpasslter

15
Dark EnerGy
DOEPFER Functions
•XMSourceswitch
This switch selects which source is to modulate the cutoff frequency exponentially. The switch toggles bet-
ween LFO2, envelope (ADSR) and no source (off). Controlling the cutoff frequency by the ADSR is one of
the most common applications as it imitates the typical timbral characteristics of most acoustic instruments
from bright- to dull-sounding. Of course, Dark Energy‘s envelope generator allows many more ways of
shaping timbre.
LFO2 produces a periodic and continuous modulation signal. Low frequencies will create sweeps similar to
a„wah-wah“pedalasusedbyguitarists.UsingtheLFO´s„high“rangesetting,XMwillgenerateverynoisy
sounds that cannot really be played tonally. This way of modulation is great for unique and interesting
„outer space type“ sound effects. Feel free to experiment with the settings of cutoff frequency, LFO2 speed
and XM pot, and keep watching the skies while you are at it.
•LMcontrol
This pot determines the depth of linear frequency modulation - a very special feature on analog synthesi-
zers. Modulation source is always the VCO triangular wave. In contrast to exponential FM, linear FM produ-
ces tonally playable sounds as long as VCF cutoff and VCO signal stay within a certain frequency range.
Highlyinterestingsoundscanbeachievedusingtheresonatinglter(highresonancesettings).
Go ahead and experiment with cutoff frequency, resonance, VCO tuning and LM knob settings. Please note
that even small parameter changes can result in drastically new timbres. Careful with that axe, Eugene!
•Resonancecontrol(Res)
Thispotdeterminestheintensityofthelterresonance.Thiseffectdependsalotonthecutoffsettingand
willbemostintenseatsettingsbetween1and5.Athighresonancesettings,thelterwillstartresonating
and will generate a waveform close to a sine wave. It can be used as an additional signal source to produce
popular sound effects, e.g. typical synthesizer percussion sounds when the cutoff is modulated by a suitab-
le ADSR setting. Think disco hits ca. 1975 and you will get an idea.
Whenthelterisself-oscillating(highresonance)andtheVCOisdisabled(waveformswitchatcenterpo-
sitionandPWpotturnedfullyclockwiseorcounter-clockwise),thelterwillworkasasinewaveoscillator.
It can be modulated by both the VCO (linear FM) and LFO2 (exponential FM) at the same time! The VCO
frequencycanfollowtheltercutofffrequency.Verycomplexsoundsensue!
•Trackingswitch
Thetrackingswitchhasthepositions„half/off/full“.Itdetermineswhetherorhowmuchtheltercutoff
frequency will depend on the pitch of the played key (resp. VCO pitch). When set to „full“, higher notes will
sound increasingly brighter, lower notes the duller the deeper you go on the keyboard. This corresponds
tothetypicalcharacterofacousticinstruments.Whensetto„half“,thiseffectislessintense.Ifthelteris
self-oscillating and is to be played tonally as an oscillator from a MIDI keyboard, this switch has to be set
to „full“. This way it recieves the same control voltage as the VCO. This setting is also useful when linear
frequencymodulation(LM)isusedwiththeresonatinglter.
•VCFFInput
Pleaseusethissocketifyouwanttomodulatetheltercutofffrequencybyanexternalcontrolvoltageor
an external audio signal. This input also uses an (exponential) 1V/Oct scaling. This way the self-oscillating
VCF can be played (almost) chromatically (the scaling is not as precise as the VCO scaling due to technical
reasons but much better than found on many other analog synthesizers.) The control voltage fed into this
input will be added to the internal CVs (Freq. knob, tracking switch, XM knob.) Please bear in mind that the
sum of these CVs cannot exceed the maximum value of the modulation depth range.
•Ext.AudioInput
It can be very interesting and musically useful to process external audio signals, such as acoustic instru-
ments,drumloopsorevencompletetracks,withthecomponentsofasynthesizer.Youguessedit–Dark
Energy offers an input socket for external audio signals which can be used as a sound source in addition to
theVCOsignals.Signalsconnectedtothissocketarefeddirectlyintothelter.Theinputismonoandwill
process levels up to 1Vpp without distortion.

16
Dark EnerGy
DOEPFER Functions
When using an external audio signal please note: Set the waveform switch to „off“ (center position), turn the
PW pot fully clockwise or counter-clockwise and shut off PWM by turning the PWM pot fully counter-clock-
wise if you want the VCO to shut up completely. To make a connected audio signal audible, Dark Energy‘s
VCA has to be opened. Turn up the VCA pot and / or play a note on your keyboard which will open up the
VCA via a gate signal and ADSR control voltage. Of course you can use the external input and the VCO in
parallel. This way you may add a second VCO (e.g. Doepfer A-110, controlled from the CV1 socket) or a
noise generator (e.g. Doepfer A-117 or A-118) as an additional sound source.
3.2.3. VCA
The VCA produces dynamic control over a third important parameter - loudness or volume. A VCA is a
voltage-controlledamplier.DarkEnergy‘sVCAissomewhatspecial:Itsresponseis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 response in comparison with standard VCAs.
The VCA has the following controls:
•Amplitudecontrol
This pot controls the level of the output signal initially independently from the ADSR /
LFO1 controls. If omly this knob is cranked up, you will hear a static tone which is not
inuencedbytheenvelopeorLFO1settings.
•AMknob(amplitudemodulation)
This pot adjusts the depth of loudness modulation by 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 quite sim-
ple:ThemaximumamplicationfactoroftheVCAis„1“.TheAMknobvalueisadded
to the amplitude knob value. If the sum of the control voltages is bigger then „1“, they
willget„compressed“or„attened“.Thiswillresult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-shape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
modulation curve to a certain degree.
•AMSourceswitch
ThisswitchselectsthesourceoftheVCA´samplitudemodulation.TheswitchtogglesbetweenLFO1,
envelope (ADSR) and no source (off). The ADSR as AM source produces a „one shot“ loudness contour.
Thismodulation–doyouremembertheltersection?-isoneofthemostimportantstandardsinsound
synthesis as it simulates the typical characteristics of the loudness contour of acoustic instruments from
loud to soft. LFO1 again generates periodic modulation. Low LFO1 frequency settings will result in tremolo.
If LFO1 runs at audio rate (high), AM will generate noisy textures not unlike distortion.
•VCAAInput
This socket delivers an input for external CVs to control the VCA amplitude with. This socket is normalised,
that means the ADSR or LFO1 will be disconnected from the VCA control input when a plug is inserted. The
modulation depth is again controlled by the AM knob. This input processes signal levels between 0 Volt and
+5 Volts. Again, this CV will be added to the internal CV determined by the AM pot.
•AudioOutput
This is where you can tap Dark Energy‘s output signal from. Maximum level is approx. 1 Vpp.

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Up to this point we have studied modules that generate or process the audio signal itself. The following
modules generate control voltages in order to modulate the sound-shaping parameters of VCO, VCF
and VCA in a dynamic way.
3.2.4. ADSR
Dark Energy‘s envelope generator (or „ADSR“) produces a sequence of four control voltages every time
a key on a connected keyboard is depressed, or when Dark Energy generates or receives a MIDI note-on
commandoragatesignal.Theenvelope´scontrolvoltagesareusedtogivethesoundadynamicshape.
The envelope produces four parameters:
    •Attack
    •Decay
    •Sustain
    •Release
As soon as the envelope generator receives a gate-on signal, its output CV will rise from 0 Volt to maxi-
mum. The rise time is adjustable and called „Attack“. When the maximum value has been reached, the
voltagewilldropwithinatimespandenedbythe„Decay“pottothe„Sustain“level.Theenvelopecontrol
voltage will stay on this level until the key is released, then it will drop to 0 Volt within the „Release“ time
dialled up.
The envelope generator features the following controls:
•controlsforAttack,Decay,SustainandRelease.
Please bear in mind that Attack, Decay, and Release determine periods of time
while Sustain is a level value.
•ADSRRangeswitch
This switch offers three different ranges (long / short / medium) for the time-rela-
ted parameters Attack, Decay and Release. Use „short“ for extremely percussive
sounds, „long“ is most useful for slowly evolving pads, medium for everything
else in between.
•Ablue-coloredLEDindicatesthestatusoftheenvelopegenerator.
•GateInputsocket(backpanel)
Instead of the internal gate signal, derived from an incoming MIDI note, the en-
velope generator can also be triggered by an external gate signal via this socket
(0/+5 to +12V). Use this socket if you wish to control Dark Energy from a CV/
Gate sequencer or keyboard.
•EnvelopeOutputsocket
From this socket the control voltage generated by the envelope generator can be
tapped and used for additional modulation purposes.
ADSR Envelope and its Parameters
Sustain
Level
Attack
Time
Decay
Time
Release
Time
+3 ... +12
V
0 V
On O
Time
ca. +8 V
CV Output LevelGate

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3.2.5. LFO1 and LFO2
A Low Frequency Oscillator produces a signal, mostly in the sub-audio range, which can be used to genera-
te periodic changes of several patch parameters. Dark Energy features two identical LFOs.
The LFOs boast the following controls:
•Frequencycontrol
This pot controls the LFO frequency, that means, the modulation rate.
•LFOrangeswitch
This switch offers three different ranges for the LFO frequency: „Low“ (periods
of up to a minute) / „Audio“ (above 5 kHz) / „Medium“ (usual LFO range - several
seconds up to some 10 Hertz or more).
Since Dark Energy‘s LFOs produce frequencies up to audio range, they can be
used to generate FM-effects with VCO pitch, VCO pulsewidth and VCF frequency
as well as AM-effects (VCA). Use this function to create complex timbres or more
abstract sound effects.
•Dual-coloredLEDs(yellow/red)indicatepositiveandnegativestatus.At
frequencies higher than approx. 30 Hz, the LEDs will be lit orange.
•Waveformswitch
This switch selects the waveform of the LFO signal (triangle / off / square) or shuts
the LFO off. Triangular is ideal for soft modulations, square generates „trills “ in
pitchorlterfrequency.
•LFO1Outputsocket
The inverted output signal of LFO1 is available from this socket. You may use it for additional modulation
routings.
Internal jumpers deliver the non-inverted signal of LFO1 or the ADSR control voltage at this socket. You
cancongurethisjumpertoyourneeds,butpleasekeepinmindthatopeningDarkEnergy‘scasingneeds
some basic skills in handiwork. If you feel unable to do this, please get in touch with Doepfer anytime (du-
ringofcehours,preferably).
Youwillndsomemoreinformationinsection3.5,„Modications“,onpage25.

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3.3. USB/MIDI Interface
3.3.1. Connection / MIDI channel
Quite likely, you want to play your Dark Energy via MIDI - there are two easy ways to do so:
 •MIDIviaUSBor
 •the„traditional“MIDI-connectionviaDINsocket.
•USB: To hook up Dark Energy in your MIDI-setup via USB, simply connect the included USB cable with
Dark Energy and with an unused USB port on your Mac or Windows PC.
Mac OSX, Windows XP (SP2 or higher), and Windows Vista offer the necessary drivers and Dark Energy
willbemountedassoonasithasbeenconnected.YouwillndanewMIDIportinyourMIDIapplication,
named „USB audio device“ (Windows XP) or „Dark Energy“ (OSX, Windows Vista), and you are ready to
go.
If this message is missing or an error message is shown, e.g. „USB device not found“, the necessary driver
has most likely not been installed or is not working properly on this computer. In this case, Dark Energy‘s
USBportunfortunatelycannotbeusedonthisspeciccomputer.Weapologizefornotbeingabletosup-
portthisparticularproblemastherecanbevariousreasonsforthatmisbehaviorwhichareveryspecic
and depend on the individual computer. Of course, you can run Dark Energy via the MIDI DIN-connection
in such a case without any problems. The same goes for an older system based on Windows or Mac that
does not provide you with the necessary drivers.
•DIN socket: You may alternatively connect Dark Energy via MIDI cable to a MIDI interface, a MIDI key-
board, or a MIDI hardware sequencer. Simply connect the MIDI output of your MIDI device with Dark
Energy‘s MIDI port. Please do not use USB and DIN connections simultaneously.
•MIDIchannelselection(Learnbutton):
In order to enable Dark Energy to receive incoming MIDI messages, the MIDI channel of both the MIDI
device and Dark Energy have to be identical. This is how you can select Dark Energy‘s MIDI channel:
–SelectthedesiredMIDIchannelonyourMIDIdevice/softwareapplication.Pleaserefertotheir
respective user manuals when in doubt.
–Pressthe„Learn“buttononthebackofDarkEnergyandkeepitdepressedforatleastonesecond.The
LEDwillstartashing,showingthatDarkEnergyisin„learnmode“.Thedelayofonesecondavoids
accidentaluseofthe„learn“mode.TheashingLEDalwaysindicatesDarkEnergy‘sactivelearnmode.
For easy access to the „learn“ button you can use a pen or a plug.
–PressthekeyonyourkeyboardwiththelowestkeythatDarkEnergyissupposedtoplay.Thiskeywill
set CV1 (pitch CV) to 0 Volt. This is approx. equivalent to 65 Hz / „C“, when tuning control and range
switcharebothintheircenterposition.Theavailablerangewillcoverveoctavesabovethatkey.The
default setting is MIDI note number 36.
–Nowyou´redone-DarkEnergy‘sMIDIchannelwillnowcorrespondtotheoneoftheconnectedMIDI
device. Dark Energy will quit learn mode automatically and return to normal running mode. If you enable
„learn“ mode accidentally, simply hit the „learn“ button again to quit.
WhenDarkEnergyreceivesaMIDInote,the„learn“LEDwillturnoffbriey.YoumayusethisasaMIDI-in
monitor, without the need to connect a sound system.

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3.3.2. MIDI to CV/Gate interface
Since Dark Energy‘s sound generation works entirely analog, and „real“ analog control voltages and gate
signals are used internally, the unit features a complete USB/MIDI-to-CV/Gate interface.
This integrated „USB/MIDI-to-CV/Gate“ interface generates not only a pitch control voltage and a gate
signal to trigger the envelope with, it also produces several control voltages derived from incoming MIDI ve-
locity and MIDI controller data. The MIDI-to-CV interface also features a simple but useful arpeggiator and
a so-called reference pitch. You have encountered the reference tone before when you selected the MIDI
channel - it was the MIDI note that set Dark Energy‘s pitch CV1 to 0 Volts and thus became the lowest key
of Dark Energy‘s key range.
All CVs and gate signals can be tapped from sockets on the back of Dark Energy. Use patch cords to con-
nect them with the module inputs on Dark Energy‘s frontpanel. This way you can control the most important
sound parameters dynamically via MIDI velocity and a MIDI controller.
Youmay„abuse“DarkEnergy‘sMIDI-to-CV/gateinterfacetocontrolanother,notMIDIedanalogsynthesi-
zerthatcomplieswiththespecicationsofDarkEnergy.
Depending on the incoming MIDI data (note on/off, notenumber, pitch bend, MIDI controller, velocity), the
interface will generate:
•Thegatesignalfortheenvelopegenerator,
•CV1:controlledbyMIDInotenumbers;1V/octscaling(internallyconnectedtotheVCO´spitch
control input)
•CV2:controlledbyMIDIpitchbenddata(rangesapprox.–2.5Vto+2.5Vor0Vto+5V,selectablevia
internal jumper). CV2 has no internal connection, it can be patched into the control inputs on Dark Energy‘s
frontpanel as desired.
•CV3:controlledbyvolumeorthesumofvolumeandvelocity(selectablevialearnmode).CV3hasno
internal connection, it can be patched into the control inputs on Dark Energy‘s frontpanel as desired. Please
refer to page 20, section (2).
•CV4:controlledbyafreelyselectableMIDIcontrollerortheproductofcontrollerdataandvelocity(con-
troller number selectable via learn mode). CV4 has no internal connection, it can also be patched into the
control inputs on Dark Energy‘s frontpanel as desired. Please refer to page 20, section (2).
By changing an internal jumper, the CV4 socket can become a second audio output. In this case, CV4 is
not available anymore. This mod allows you to use Dark Energy without any cable plugged into the front-
panel. The default setting is CV4.