4ms EnvVCA User manual

Dual EnvVCA
4ms Company
User Manual 1.0 – October 31, 2022
The Dual EnvVCA is a dual analog envelope generator, slew limiter, and VCA. Each of the two
channels are identical and can be used separately or together.
Dual EnvVCA features:
•Versatile linear envelope generator/LFO
•Low-noise, low-distortion, DC-coupled exponential VCAs
•100% analog
•Sliders and Range switches control Rise and Fall times from ~1.25ms (800Hz) to > 2 min.
•Time CV jack extends time range: ~125µs (8kHz) to ~10 min.
•Independent attenuverters for Rise and Fall time
•Blue/Red LEDs indicate strength and polarity
•Cycle buttons for looping envelopes (LFO)
•Trigger input jacks fire a one-shot envelope
•Cycle gate input jack toggles cycling for both channels
•EOR/F (End of Rise/Fall) gate outputs can be used to chain and sequence events
•Env Level and Offset knobs scale and shift Env Out without changing VCA volume
•Audio In and Out jacks for passing audio or CV through the VCA
•VCA CV inputs to use VCAs independently from the envelopes
•VCA gain internally connected to envelope output when VCA CV jack is left unpatched
•Follow input jacks allow for slew limiting, sustain (ASR), and exotic filtering effects
• Re-trig jumpers allow for re-triggering during rise phase
Rise Fall
Rise Fall Rise Fall
Level
Rise Fall
Cycle
Follow Follow
Trigger
Time CV
Rise Fall
Time CV
EOR
In In
FallRise
Level
Offset Offset
Slow
Fast
Slow
Fast
Audio B
Out Out
Audio A
A B
VCA CVVCA CV
Trigger
B
EOF
ENV
OUT
ORA
Env
Out
Slow
Fast
Med
Slow
Fast
Med
Dual EnvVCA
A

Table of Contents
Setting up your Dual EnvVCA! "................................................................................3
Controls and Jacks! "................................................................................................3
Rise and Fall Time Ranges! "....................................................................................6
Patch: Making Notes! ".............................................................................................7
Making Notes (basic)! ".......................................................................................7
Making Notes in Stereo! "...................................................................................7
Synchronizing channels: Making Notes Using Triggers! "...................................8
Patch: Ratcheting! "..................................................................................................9
Self-Patched Ratcheting! "..................................................................................9
Ratcheting with a Clock Divider! ".......................................................................9
Patch: Making an Oscillator and Synth Drums! "....................................................10
Making an Oscillator! "......................................................................................10
Making a Kick Drum! ".......................................................................................10
Making other Synth Drum sounds! ".................................................................11
Self-patching ideas! "..............................................................................................12
Frequency Modulation (FM)! "...........................................................................12
Chaotic FM! "....................................................................................................12
Utility Patches! "......................................................................................................12
Attenuator! "......................................................................................................12
Trigger Delay with Pulse Width control! "..........................................................12
Inverted Trigger Delay (With Pulse Width Control)! ".........................................12
DC generator (Manual CV)! ".............................................................................12
Creating Envelopes (Trigger, Cycle, Follow)! ".........................................................13
Triggering with RETRIG Jumper Off (Factory Default)! "...................................13
Triggering with RETRIG Jumper On! "...............................................................13
Cycle Button/Jack! ".........................................................................................13
Follow Jack with Gates! "..................................................................................14
Fundamentals of the Follow Jack! "........................................................................14
Sidechaining (Envelope Following)! "................................................................15
Audio filter! "......................................................................................................15
Portamento/glide! "...........................................................................................15
Creating ASR and ADSR Envelopes! "....................................................................16
ASR envelope! "................................................................................................16
ADSR envelope! "..............................................................................................17
Generating Exponential and Logarithmic Envelopes! "...........................................18
Using Offset and Level Knobs! ".............................................................................19
RETRIG Jumper! "...................................................................................................19
VCA Min Gain Trim pot! "........................................................................................19
Electrical and Mechanical Specifications!............................................................20
Page of2 20

Setting up your Dual EnvVCA
1. Power off your Eurorack system.
2. On the back of the Dual EnvVCA you will see a 10-pin header. The 10-pin
header connects to a Eurorack power header using the included power
cable. Connect the 16-pin end of the power cable to a 16-pin Eurorack
power header on your power supply distribution board and the 10-pin end to
the Dual EnvVCA with the red stripe on the power cable oriented towards
the bottom of the module.
3. Using the included screws, securely attach the Dual EnvVCA to the rails of
your case.
4. Power on your Eurorack system.
Note: The Dual EnvVCA is reverse-polarity protected, but incorrectly connecting any module in any
system can damage other modules on the power bus.
Controls and Jacks
Cycle Buttons and Cycle Jack
The Cycle buttons toggle the cycling state for each channel. When cycling,
the Dual EnvVCA behaves like an LFO, with an output waveform that
continuously rises and falls. Each button illuminates orange to indicate the
module is cycling. Note that pressing this button does not reset or alter an
envelope that’s already rising or falling.
The Cycle jack toggles the cycle state of both channels. If a Cycle button is
off, a gate signal will turn the button on and make the channel cycle for as
long as the gate is held high. If a Cycle button is on, then a gate signal will
turn the button off and cease any cycling for as long as the gate is held high.
See Cycle Button/Jack on page 13 for more information.
Rise/Fall Sliders
The Rise and Fall sliders control the rise and fall times of the envelope.
Shifting a slider up makes the rise or fall portion slower, shifting down makes
it faster.
Each slider has a white light that indicates the current stage and output
voltage of the envelope. When the envelope is in the rise stage, the Rise
slider light will increase in brightness until the envelope hits its maximum.
Once the peak is reached, the Rise light will turn off and the Fall light will turn
on, decreasing in brightness as the envelope falls.
Rise/Fall Switches
The Rise/Fall switches select the overall range of the sliders. Each slider has
its own switch with three positions: Fast, Med, Slow.
When the switch is flipped to Fast, the envelopes go well into the audio
range, allowing for classic AM, FM, and other fast modulation effects.
The middle position (Med)is designed for typical musical tempos, and can be
useful when using the VCA to make notes at common BPMs.
The Slow position is geared for gradual fades and other slow LFO-style
modulations.
See the Rise and Fall Time Ranges chart on page 6 for more information.
Page of3 20
Cycle
Rise Fall
Slow
Fast
A
Rise Fall
Slow
Fast
Med

Time CV Jack and Rise/Fall CV Knobs
The Time CV jack modulates the Rise and Fall times of the envelope. The
jack feeds two knobs: Rise CV, and Fall CV. Each of these knobs is an
attenuverter (short for “attenuating inverter”) and controls how much the
control voltage on the Time CV jack will affect either the rise or the fall time.
Turning an attenuverter knob to the right of center means that a positive
voltage on the Time CV jack will lengthen the rise/fall time and a negative
voltage will shorten the rise/fall time.
Turning a knob to the left of center gives the opposite effect, meaning that a
positive voltage on the Time CV jack will shorten the the rise/fall time, while a
negative voltage will lengthen these durations.
The farther you turn the knob from center in either direction, the more effect
incoming CV will have. When the knob is centered, the signal on the Time
CV jack will have no effect on the rise or fall time.
Next to each knob is a light which indicates the strength and polarity of the
modulation. The light will turn blue when the rise or fall time is being
lengthened by CV, and red when the time is being shortened. The brighter the
light, the more of an effect the CV is having. When the light is off, the Time
CV jack has no effect on the envelope time.
When nothing is plugged into the Time CV jack, the knobs act as fine-tuning
controls for the Rise and Fall times.
Env Out Jacks, OR Jack, and LEDs
The Env Out A and B jacks output the envelopes for each channel. DC offset
and vertical scale of each channel’s envelope are determined by the positions
of the Level and Offset knobs. The OR jack compares both Env Out signals
and outputs the highest voltage value between the two at any given moment.
The lights near each jack indicate the amplitude and polarity of each
envelope. When the envelope is somewhere between 0V and 10V, its
respective light will shine blue. When the envelope is somewhere between
-10V and 0V the light will shine red. The brightness of each light indicates the
amplitude of the outgoing signal, so when the light is off, this means the
signal is outputting at or around 0v.
Level and Offset Knobs
The Level knob attenuates and inverts (attenuverts) the envelope output on
each Env Out jack. When Offset is centered, turning Level fully clockwise
will output a positive envelope, with a maximum peak of about 10V. Turning
the knob counter-clockwise inverts the envelope. When Level is fully counter-
clockwise, the output will peak at about -10V.
Turning the Offset knobs clockwise will add a positive offset between 0V and
10V to the envelope, while turning the knobs counter-clockwise will add a
negative offset between 0V and -10V. See Using Level and Offset on page 18
for more details.
Note that neither the Level pots nor the Offset pots affect the envelope going
to the internal VCAs. For example, if the Env Out jack is patched to a
modulation input on an external module while audio is running through the
VCA, Level and Offset can be used to control the amount of modulation
without changing the audio level.
EOR and EOF Output Jack
The EOR (End of Rise) jack is specific to Channel A. It outputs a gate that
goes high when the rise stage ends and the fall stage begins. It remains high
as long as the envelope is falling, and goes low when the envelope
completes. When the envelope is not running, the EOR jack will stay low. The
EOR light will shine whenever the output is high.
Page of4 20
Rise Fall
Time CV
BORA
Env
Out
EOR
EOF
Level Level
Offset Offset
ENV
OUT

The EOF (End of Fall) jack is specific to Channel B. It outputs a gate that
goes high when the fall stage ends, and remains high until the envelope
begins rising. Said another way, the gate at the EOF jack only goes low
during the rise stage. The EOF light will shine orange when the EOF output is
high.
Audio In, Audio Out, and VCA CV Jacks
The Audio In and Out jacks are the input and output of the VCA. The
envelope output (pre-level and offset pots) is internally routed to the VCA CV
input. When the envelope is stopped or at 0V, the Out jack will output silence.
As the envelope rises, the signal will get louder until it becomes as loud as
the input signal at the peak of the envelope. As the envelope falls, the signal
will fade back to silence. Audio In Bis normalized to Audio In A, as
indicated by the graphics on the faceplate. So when Audio In B is
unpatched, the Audio In A signal will be sent to both channels. Patching into
Audio In B will break this connection so that both channels are operating
independently.
When patched, the VCA CV jacks break the internal connection between
envelope and VCA, allowing for independent use of the VCA. The VCA CV
input has a range of 0 to 5V, which translates to about -90dB (silence) to 0dB
(unity gain).
Trigger Jacks
Each Trigger jack requires a trigger of at least 2V to start an envelope. If
there is no envelope in progress, then a trigger will initiate a single complete
envelope. If the envelope is rising when a trigger is received, then the trigger
is ignored (unless the RETRIG jumper is installed, see below). If the envelope
is falling when a trigger is received, it will begin rising from its current voltage.
On the back of the module is a RETRIG jumper for each channel. When this
jumper is installed, the envelope will immediately jump to 0V and start rising
any time a trigger is received. This can cause a click on the VCA output, so
the jumper is not installed at the factory.
Follow Jack
The Follow jack is the input of a slew limiter, and can also be used for
complex envelope generation, exotic audio filtering, and envelope following.
Whenever the internal envelope is not triggered or cycling, the envelope
output will rise or fall in order to match the voltage level present on the
Follow jack. However, the rate of rise and fall times is limited by the positions
of the Rise/Fall sliders and the CV amounts. That is, the envelope output will
try to “follow” the signal present on the Follow jack, but it can only rise and
fall as fast as the envelope would rise/fall if it were to be triggered. Since
“slew” is the rate of change, we call this “slew limiting”.
Slew limiting can be used to create complex envelopes (ASR, ADSR, etc) by
timing the signal on the Follow and Trigger jacks. See Fundamentals of the
Follow Jack on page 14 for more information.
Page of5 20
Follow
Trigger
In
Audio B
Out
VCA CV
A

Rise and Fall Time Ranges
Note that the switch positions have little effect on the range obtained by using CV. This is intentional, to
allow external modules control over the full range.
Because of its analog nature, the maximum and minimum rise and fall times vary from unit to unit. The
table above shows typical values.
The rise and fall times will not necessarily be equal when the sliders are in the same position. For
precisely equal rise and fall times, manual adjustment is usually needed. When applying CV to make
very slow envelopes (greater than 10 minutes), the fall time can be made much slower than the rise
time. Typically the rise time is limited to about five minutes, while the fall time can go up to 20 minutes
or up to an hour on some units.
Page of6 20
Switch Position
Slider
Range
(total env.
time)
Max Range
with CV
(total env.
time)
Use Cases
Slow
5 min. to
1.5 sec.
~30 min. to
300Hz
Gradual, slow fades or modulation changes
occurring over the course of a long time.
Med
20 sec. to
18Hz
~9 min. to
1kHz
Generally suited for typical musical tempos. Useful
for making notes, from snappy percussive sounds to
long decays. The slower slider settings approach
LFO ranges.
Fast
2.5Hz to
800Hz
~8 min. to
8kHz
Good for FM, AM or other audio-rate modulation.
Snappy attacks and sharp decays.
Fast
Med
Slow
Fast
Med
Slow
Fast
Med
Slow

Patch: Making Notes
Making Notes (Basic)
Patch a sound source into the Audio In A jack, and patch the Audio Out A jack to your mixer or amp
so you can hear it on speakers or headphones. When choosing the sound source, try to find something
that makes a continuous tone or drone, such as a VCO like the Ensemble Oscillator.
When the left Cycle button is on (button is shining orange), you should hear notes being played at a
steady tempo. The notes should have a sharp attack (quick fade-in) and longer decay (slower fade-
out).
Try moving the Rise slider up and listen to how the sound fades in more slowly. Then move the Fall
slider down and hear how the fade-out gets faster. Continue to experiment with the slider positions,
listening to how the sound and tempo change. Try flipping the switches to Fast and hear how much
faster the envelope gets.
Next, patch the Env Out jack to a modulation input on the sound source. For example, if you’re using
the Ensemble Oscillator, try patching it to the Warp jack. For other VCOs, try a PWM or wave-shaper
input. Adjust the Level and Offset knobs to control the amount of modulation. When both knobs are
centered, you should hear no modulation.
Making Notes in Stereo
So far we’ve just used Channel A, but this patch can be duplicated on Channel B to process two sound
sources or a single stereo sound source. Try doing this now, by patching the second output of the
Ensemble Oscillator or some other sound source into the Audio In B jack. If you don’t have another
sound source, you could leave Audio In B unpatched and the signal from In A will be routed there
automatically, but using a stereo sound source (or two mono sound sources) has a nicer effect.
Patch the Audio Out B jack to the mixer (adjust the panning if your mixer supports that). Turn channel
B Cycle on. Adjust the Rise and Fall sliders and set the switches to center. You should hear both
sound sources playing at different tempos.
Page of7 20
Rise Fall
Rise Fall Rise Fall
Level
Rise Fall
Cycle
Follow Follow
Trigger
Time CV
Rise Fall
Time CV
EOR
In In
FallRise
Level
Offset Offset
Slow
Fast
Slow
Fast
Audio B
Out Out
Audio A
A B
VCA CVVCA CV
Trigger
B
EOF
ENV
OUT
ORA
Env
Out
Slow
Fast
Med
Slow
Fast
Med
Dual EnvVCA
A
To mixer/output amp
From sound source
(e.g. a VCO)
Cycle on
Switches set to Med
Rise slider at Fast,
Fall slider in middle
(adjust to taste)
Optional:
To VCO modulation input
(FM, waveshape, etc.)
Optional:
adjust amount of
modulation
Stereo patch: to mixer/
output amp
Stereo: From right
channel of sound source
(or a different sound
source)

Synchronizing Channels: Making Notes Using Triggers
With the previous patch, the tempo of each channel is linked to the rise and fall times of the envelopes.
It’s not possible, for example, to have quick, short notes at a slow tempo. It’s also nearly impossible to
adjust the sliders so both channels are going at the exact same tempo.
By turning channel A’s Cycle off and patching the EOF trigger from channel B to channel A’s Trigger
jack, we can synchronize the channels and separate channel A’s envelope length from its tempo. Try
doing this now.
Every time channel B ends an envelope and begins a new one, an EOF pulse fires, causing channel A
to start an envelope. Channel A’s Rise/Fall sliders control the envelope length without changing the
tempo. Channel B’s sliders control the tempo for both channels as well as the envelope for channel B.
If you want to decouple channel B’s envelope length from its tempo, you could turn off Cycle and patch
an external clock or LFO into channel B’s Trigger jack. Now the external clock controls the tempo and
each channel’s sliders independently control the envelopes.
Adding Chaos
You can create some inter-related pattens by patching Channel A’s EOR jack into Channel B’s Trigger
jack, leaving EOF patched to Channel A’s Trigger jack, and turning off both Cycle buttons. Now both
channels trigger each other. For some extra chaos, patch the Env Out OR jack to one of the Time CV
jacks, and patch the EOR jack into the Cycle jack instead of channel B’s Trigger jack. Press one of the
Cycle buttons to start the chain of events, then play with the sliders, the Rise/Fall CV knobs, and the
Level and Offset knobs until you find sweet spots where random patterns emerge.
Page of8 20
Rise Fall
Rise Fall Rise Fall
Level
Rise Fall
Cycle
Follow Follow
Trigger
Time CV
Rise Fall
Time CV
EOR
In In
FallRise
Level
Offset Offset
Slow
Fast
Slow
Fast
Audio B
Out Out
Audio A
A B
VCA CVVCA CV
Trigger
B
EOF
ENV
OUT
ORA
Env
Out
Slow
Fast
Med
Slow
Fast
Med
Dual EnvVCA
A
To mixer/output amp
From left channel of
sound source
Cycle off
Switches set to Med
Channel A Rise/Fall
sliders set channel A
note length
To VCO modulation input
(FM, waveshape, etc.)
Optional:
adjust amount of
modulation
To mixer/output amp
From right channel of
sound source
Cycle on
Channel B Rise/Fall
sliders set overall tempo,
and channel B note
length
Patch EOF to
channel A Trigger

Patch: Ratcheting
Self-Patched Ratcheting
In this patch we’ll make a ratcheting effect where the notes play at a steady tempo for a while, and then
periodically speed up in a rapid burst. Start with the Making Notes patch on Channel A, with Cycle on
and the Audio In/Out jacks patched to a sound source and mixer. With the Time CV knobs centered,
you should be hearing notes at a steady tempo.
Turn on Cycle for Channel B. Adjust the Rise and Fall sliders of Channel B so that it’s going at least
four times as slowly as Channel A. Patch the EOF output of Channel B to the Time CV input of
Channel A. Turn Channel A’s Rise CV and Fall CV attenuverters slightly to the left, so that when the the
EOF jack fires a pulse, the notes play at a faster rate.
Adjusting the Rise time of Channel B will change the pulse width of the EOF pulse, thus controlling the
duration of the rapid bursts. The sum of the Rise and Fall times on Channel B controls how often the
ratcheting occurs. Try adjusting these parameters slightly to hear the effect it has on Channel A.
Ratcheting With a Clock Divider
With the previous patch, it’s hard to specify the exact relationship between the base tempo of Channel
A and Channel B. Using a clock divider module such as the RCD or QCD can give us more control.
Unpatch the cable from EOF to Time CV. Turn off Channel A’s Cycle and patch the clock divider’s
undivided output to Channel A’s Trigger jack. Adjust the speed of the clock divider to set the base
tempo. Next, patch a divided output from the clock divider (say, /8) to the Cycle jack and Channel A’s
Time CV jack. Adjusting the pulse width of the divided clock controls the duration of the rapid bursts.
Adjusting the amount of clock division controls how often the bursts happen.
Page of9 20
Rise Fall
Rise Fall Rise Fall
Level
Rise Fall
Cycle
Follow Follow
Trigger
Time CV
Rise Fall
Time CV
EOR
In In
FallRise
Level
Offset Offset
Slow
Fast
Slow
Fast
Audio B
Out Out
Audio A
A B
VCA CVVCA CV
Trigger
B
EOF
ENV
OUT
ORA
Env
Out
Slow
Fast
Med
Slow
Fast
Med
Dual EnvVCA
A
To mixer/output
amp
From sound source
(e.g. a VCO)
Cycle on
Switches and sliders
set to taste
Rise/Fall CV turned to
the left. Controls speed
of ratcheted
envelopes.
Cycle on
Switches and
sliders set to
taste. Rise time
sets how long
ratcheting lasts.
Rise plus Fall
sets how often
ratcheting
occurs.
Optional: To VCO
modulation input

Patch: Making an Oscillator and Synth Drums"
Making an Oscillator
In this patch we’ll use Channel A of the Dual EnvVCA as an oscillator and Channel B as the modulator
to create a kick drum sound.
To make the oscillator, flip the Rise and Fall switches of Channel A to Fast. Patch the Env Out A jack
to a mixer. Engage the Cycle button to begin oscillation. You can change the pitch by adjusting the
sliders. If both sliders are approximately at the same position, you’ll get a triangle wave output. If one is
substantially higher or lower than the other, the output will resemble a ramp or saw wave. For pulse
wave shapes, you can take the signal from the EOR jack instead of Env Out A. In this case, adjusting
the sliders separately will change the pulse width.
Making a Kick Drum
To make a kick drum sound, first use the sliders to set the pitch of Channel A low enough so that you
can’t hear sound. Set the sliders to equal positions. Now we will modulate the pitch by patching the Env
Out B jack to Channel A’s Time CV jack. Set Channel A’s Rise and Fall CV attenuverters to be fully
CCW. Fire triggers into Channel B’s Trigger jack to hear the pitch of Channel A modulate. Adjusting the
Level knob on Channel B will change the amount the pitch rises: typically for a classic analog kick
sound the knob should be around 1 or 2 o’clock. The Rise and Fall sliders of Channel B will adjust the
attack and decay. A typical drum will have a sharp attack and slower decay, so start with the Rise slider
and switch at Fast, and the Fall slider and switch in the middle positions.
An exponential modulation curve makes a more extreme kick drum sound. To create this, split the
signal coming out of Env Out B to also go to Channel B Time CV. Adjust Channel B’s Fall CV knob to
left of center (try at about 10:00), and keep the Rise CV knob at center. If you adjust Channel B’s Level
knob, you also will need to adjust Channel A’s Rise and Fall CV knobs to set the amount of pitch
modulation.
Page of10 20
Rise Fall
Rise Fall Rise Fall
Level
Rise Fall
Cycle
Follow Follow
Trigger
Time CV
Rise Fall
Time CV
EOR
In In
FallRise
Level
Offset Offset
Slow
Fast
Slow
Fast
Audio B
Out Out
Audio A
A B
VCA CVVCA CV
Trigger
B
EOF
ENV
OUT
ORA
Env
Out
Slow
Fast
Med
Slow
Fast
Med
Dual EnvVCA
A
Cycle off
To mixer/output amp
Cycle on
Switches to Fast.
Rise and Fall sliders
control attack and
decay of kick drum
Sliders set the base
pitch and waveshape
Rise/Fall CV fully to
the left
Rise switch to Fast.
Fall switch to Med.
Level controls
amount of modulation
Level controls volume
From trigger source
(gate sequencer,
clock, manual trigger,
etc.)

Making Other Synth Drum Sounds
In the Making an Oscillator patch, we created a kick drum which decays to an inaudible tone below the
range of human hearing. To create a higher-pitched drum, such as a tom-tom, we will need a VCA to
cut off the audio after the drum decays.
Raise the pitch of Channel A using the sliders or Channel B’s Offset knob. You should hear a steady
tone between Channel B firing. Now we’ll route this sound through Channel B’s VCA. Unpatch the
cable going to the mixer and patch it into Audio Out B instead. Patch a cable from Env Out A to Audio
In B. Now you should hear a similar drum sound, but it will be silent between hits. If you are using the
exponential modification in the previous patch, you probably will want to dial it back because the VCA
itself has an exponential response.
To add some noise to the sound, you can patch an external oscillator into Audio In A. Then move the
patch cable going from Env Out A to Audio In B so that it goes from Audio Out A to Audio In B. The
external oscillator will be amplitude modulated (AM) with the synth drum sound, and this resulting
sound will be VCA’ed with Channel B’s envelope. Play with Channel A’s sliders and Rise/Fall CV knobs
to hear the range of possible sounds. Next use any of the Env Out jacks to modulate the external
oscillator in time with the synth sound.
Try adding slight modulation to the Time CV of Channel B to create organic, naturally changing drum
sounds. A slow LFO or a CV sequencer will work nicely.
Page of11 20
Rise Fall
Rise Fall Rise Fall
Level
Rise Fall
Cycle
Follow Follow
Trigger
Time CV
Rise Fall
Time CV
EOR
In In
FallRise
Level
Offset Offset
Slow
Fast
Slow
Fast
Audio B
Out Out
Audio A
A B
VCA CVVCA CV
Trigger
B
EOF
ENV
OUT
ORA
Env
Out
Slow
Fast
Med
Slow
Fast
Med
Dual EnvVCA
A
Cycle off
To mixer/output amp
Cycle on
Switches to Fast.
Rise and Fall sliders
control attack and
decay of kick drum
Sliders set the base
pitch and waveshape
Rise/Fall CV fully to
the left
Rise switch to Fast.
Fall switch to Med.
Level controls
amount of modulation
Level controls volume
From trigger source
(gate sequencer,
clock, manual trigger,
etc.)
Optional: Sound
source to be AM’ed
Optional: To mixer/
output amp

Self-patching ideas
Frequency Modulation (FM)
Turn both channels’ Cycle on, and switches to Fast. Start with all sliders in the center position. Use
Channel B to modulate the frequency of Channel A by patching Env Out B into Channel A’s Time CV
jack. Adjust both Rise and Fall CV knobs to around 9:00. Turn both Level knobs fully clockwise and
center Offset knobs. Listen to the output on Env Out A, or for a mix of both oscillators, use Env Out
OR jack. Slowly adjust Channel B’s sliders and listen to how the sound changes. Then slowly adjust
Channel A’s sliders and Rise and Fall CV knobs to hear the effect.
The Rise and Fall sliders of Channel B control the modulation frequency, and Channel A’s Time CV
knobs control the modulation amount. Channel A’s sliders control the base frequency, also known as
the carrier frequency.
Chaotic FM
For chaos, start with the FM patch above, and then use Channel A to modulate Channel B by patching
Env Out A into Channel B’s Time CV. Start with Channel B’s Rise and Fall CV knobs set to about
10:00. Take the output from Env Out OR. To find interesting chaotic sounds, you probably will need to
move the sliders to a slower position and the Rise/Fall CV knobs more towards center than in the FM
patch.
Utility Patches
Attenuator
Patch a signal that you want to attenuate into Audio In (either channel), and take the output from
Audio Out. Patch Env Out to VCA CV. Use Offset to adjust the attenuation amount (typically between
12:00 and 2:00 is a good setting). If you are using the envelope portion of the channel (Cycle is on or
you are triggering the channel), set Level to center or else the envelope will bleed into the attenuator
output.
Trigger Delay With Pulse Width Control
Turn Channel A’s Cycle off. Send a trigger into Channel A’s Trigger jack. Take the output from EOR.
Adjust the Rise slider and switch to set the trigger delay time (rising edge of incoming trigger to rising
edge of outgoing trigger). Set the Fall slider and switch to control the width of the outgoing trigger.
Inverted Trigger Delay (With Pulse Width Control)
Same as the previous patch, but use Channel B’s Trigger jack and EOF. Rise controls the amount of
delay (rising edge of incoming trigger to falling edge of outgoing inverted trigger) and Fall controls the
width of the inverted trigger.
DC generator (Manual CV)
When a channel is not running, the Offset knob will produce a steady DC voltage on the Env Out jack.
If the channel is running, set Level to center.
Ducking (Sidechaining)
A ducking effect reduces the volume of a sound at the same time a secondary sound plays. If the
secondary sound is generated by triggers in your patch, you can easily create this on the Dual
EnvVCA by generating an inverted envelope and patching it into the VCA.
To achieve this effect, split the trigger that’s triggering the secondary sound and patch it into the Trigger
jack of one channel. Turn Cycle off. Adjust Rise and Fall to create the envelope you want (typically the
rise will be shorter than the fall). Patch an audio signal into Audio In and take the output from Audio
Out. You should hear your sound play every time the trigger fires. In order to create the inverse
behavior (get more quiet when the trigger fires), patch Env Out to VCA CV and turn Level to about
9:00 and Offset to about 3:00.
If the secondary sound source is not generated by triggers in your patch (perhaps because it’s an audio
track), see Sidechaining (Envelope Following) on page 17.
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Creating Envelopes (Trigger, Cycle, Follow)
There are four ways to generate an envelope with the Dual EnvVCA:
using the Trigger jack, the Cycle button, the Cycle jack, or the Follow
jack.
The Trigger jack starts an envelope when it receives a trigger. It only
responds to rising edges, that is, when the voltage rises through 2V.
Figure 1 shows how a long or short pulse will cause identical
envelopes since the pulse width and falling edge of the signal are
ignored.
Triggering with RETRIG Jumper Off (Factory Default)
If the envelope is already rising when a trigger is received, then the
trigger is ignored (unless the RETRIG jumper is installed). If the
envelope is falling when a trigger is received, it will begin rising from its
current voltage. Figure 2 demonstrates this: the fifth and seventh
triggers occur while the envelope is falling and cause it to begin rising
mid-fall. The rest of the triggers either occur while the envelope is
rising and are ignored, or while the envelope is not running, causing it
to start.
Triggering with RETRIG Jumper On
Figure 3 shows how the RETRIG jumper changes the behavior. With
the jumper installed, a trigger will always reset the envelope to zero
and begin rising, regardless the stage of the envelope. This sharp
transition to 0V can cause a click when used with audio, so the jumper
is not installed by default.
Cycle Button/Jack
The Cycle button is a simple way to initiate an envelope. When the
button is on, envelopes will cycle continuously. The button is latching,
so pressing it once will make the module output envelopes until you
press the button again. Once an envelope begins, pressing the Cycle
button again will not immediately stop the envelope. Instead, the
envelope will stop after finishing its fall stage.
The Cycle jack toggles the cycling state of both channels when a gate
is received. It’s utilized in tandem with the Cycle buttons. If a
channel’s button is initially off, a gate signal at the Cycle jack will
toggle it on. If the button is initially on, a gate at the jack will toggle it
off. The Cycle button will shine orange whenever the combination of
the Cycle jack and Cycle button causes the envelopes to cycle.
In Figure 4,the Cycle button is initially off, and the incoming gate
signal on the Cycle jack causes the envelope to cycle for as long as
the gate is high. In this case, as the pulse width of the gate signal gets wider, the Dual EnvVCA outputs
more cycles.
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Figure 1: Trigger jack pulse width
does not change Env output.
Figure 2: RETRIG jumper off.
Triggers on rise stage have no
effect. Triggers on fall stage switch
to rising.
Figure 3: RETRIG jumper installed.
Triggers always restart the envelope.
Figure 4: When Cycle button is off, high gate on Cycle
jack makes envelope run.
Figure 5: When Cycle button is on, high gate on Cycle
jack makes envelope stop.

Figure 5 shows the opposite state; the Cycle button is initially on, so the incoming gate signal stops the
cycling for as long as the gate is high. In this case, as the pulse width of the gate signal gets wider,
there are longer pauses between groups of envelopes.
Note that the first pulse in Figure 5 does not stop the envelopes, and the three rapid pulses in Figure 4
only cause one envelope. This illustrates an important aspect of the Dual EnvVCA: the state of the
Cycle jack and button only matter when the envelope is stopped (at 0V). Any combination of gates and
button presses while the envelope is running have no effect; it’s only when the envelope finishes
running that the Cycle jack or button can make it cycle again.
Follow Jack With Gates
Figure 6 illustrates the use of gates on the Follow
jack. A gate signal will cause the envelope to rise as
long as the gate is high. When the gate goes low,
the envelope will fall.
The fourth gate in Figure 6 shows that if the gate is
held high while the envelope reaches its maximum,
the envelope will hold (sustain) until the gate is
released. This is an easy way to create an ASR
envelope (Attack Sustain Release).
The short burst of pulses at the end illustrates how
the Follow jack can be utilized to create complex
envelope shapes using only a sequence of gates.
The Follow jack can be used with more than gates, see the next section for a detailed discussion.
!
Fundamentals of the Follow Jack
The Follow jack causes the envelope to rise or fall in order to “follow” the signal on the jack. Sending a
high voltage (5V) into the Follow jack will cause the envelope to rise. Sending a low voltage (0V) will
cause it to fall. This can be seen in Figure 6 of the previous section.
Sending voltages between 0V and 5V, such as a waveform from an LFO, or an audio signal will have
more complex effects.
There are two basic rules that govern this jack:
Rule 1: If the voltage on the Follow jack is greater than the envelope voltage, the envelope will
rise; if the voltage on the Follow jack is less than the envelope voltage, the envelope will fall.
That is, the envelope will always “seek” the Follow signal: it will go up if the Follow signal is higher,
and it will go down if the Follow signal is lower. This is where the term “follow” originates.
Rule 2: The envelope can only rise and fall at the speed set by the Rise/Fall controls and CV.
This means that if the Follow jack suddenly jumps up (for example, when a gate is applied), the
envelope will try to follow that jump by rising, but it can only rise as fast as the controls allow it. The rate
of change, or slew, is limited, thus we call the Follow circuit a “slew limiter”.
Note that the term “envelope voltage” in Rule 1 refers to the internal envelope voltage, before the Level
and Offset knobs and Env Out jack output driver. Internally, the envelope has a maximum of 5V and
minimum of 0V, which is why the Follow jack only responds to voltages from 0V to 5V. The Env Out
jack’s output driver doubles the internal voltage, so a 5V internal envelope corresponds to
approximately 10V envelope on the jack.
Armed with these two basic rules, we can now showcase some advanced uses for the Follow jack in
the following sections.
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Figure 6: Sending gates into the Follow jack. When the
input gate goes high, the envelope rises; when the input
goes low, the envelope falls.

Sidechaining (Envelope Following)
The Follow jack can be used to create an envelope that follows an audio signal’s envelope. This
envelope can be inverted and used to control a VCA, creating a “ducking” effect on another sound. This
technique is called sidechaining.
A common application is to use a kick drum to duck another sound source, for example, a background
drone. Patch an audio source that’s making a kick drum sound into the Follow jack of Channel B. Make
sure Cycle is off. Start with the switches at Med, the Rise slider all the way down, and the Fall slider in
the center. If you turn Level up, the Env Out B jack will be outputting an envelope that roughly follows
the kick drum’s envelope. Adjusting Rise and Fall will control the attack and release of the envelope,
that is, how quickly the envelope responds to the attack and release of the kick drum.
For this example we want to invert the envelope, so turn Level all the way counter-clockwise, and turn
Offset to around 2:00. Env Out B will now be outputting an inverted envelope that rests at about 5V
and then ducks down when the kick drum plays. Patch this inverted envelope into Channel A’s VCA CV
jack. Run the audio that you want to be ducked (e.g. a drone sound) into Channel A’s Audio In, and
listen to the output on Audio Out. You should hear the drone play at normal volume, and then briefly
get more quiet whenever the kick drum fires. Try listening to the drone and the kick drum
simultaneously to get the full effect.
Adjust Channel B’s Rise and Fall sliders to control how quickly the envelope responds. If the sliders
are set too fast, the envelope will trace the individual peaks of the sound wave, not the overall
envelope, and the result will be like a subtle AM effect. If the sliders are set too slow, the volume won’t
change much when the kick drum fires.
You can also adjust Channel B’s Offset and Level knobs to control the dynamic range of the ducking. If
you want less ducking, turn Level towards center to reduce the amplitude of the envelope. On the other
hand, if the kick drum is quiet you may need to turn Level towards the extreme counter-clockwise
position to generate an envelope with enough amplitude to get the amount of ducking you want. Offset
almost always needs to be between 1:00 and 3:00. If it’s too low, the output will be too quiet, and if it’s
too high, the output will be at maximum volume with very little ducking.
Audio Filter
The Follow jack can be used as an exotic audio low-pass filter by taking advantage of its slew-limiting
properties. First, the audio signal must be shifted up such that it’s within the range of 0V to 5V. Typically
a level shifter can be used to add the required DC offset. You may also need to attenuate the audio so
that it’s no more than 5V. Any signal outside this range will be clipped, resulting in harsh distortion.
Patch this adjusted audio into the Follow jack. Patch the Env Out jack to your mixer/amp. Turn Level
all the way up and turn Offset to center. To start, set the Rise/Fall sliders and switches to the fastest
positions. Send a steady positive voltage into the Time CV jack and turn the Rise CV and Fall CV
knobs all the way down.
At this point you should be hearing an audio signal that is similar to the original signal.
Now make the rise and fall times slower by adjusting the Rise/Fall CV knobs and sliders, or by
adjusting the CV patched into the Time CV jack. As you do this, you should hear the audio get more
muffled, as the slew becomes limited and higher frequencies can no longer pass.
To make more exotic sounds, try just adjusting the rise or the fall time. This will let the rising portions
and falling portions of higher frequencies pass differently, creating some unique harmonics.
Waveshaper
By limiting the slew, wave shapes with sharper transitions can be altered to have smoother transitions.
For instance, feeding a square wave into the Follow jack will produce a trapezoidal or triangular wave
on the Env Out jack. Adjust the Rise/Fall sliders and switches to get a maximum amplitude output
waveform while still performing the desired amount of waveshaping. These controls will need to be re-
adjusted if the frequency of the waveform changes. You may be able to use the Time CV jack and
Rise/Fall CV knobs to track the frequency and create a somewhat consistent variable-frequency wave
shaper.
Portamento/Glide
The output of a CV/Gate keyboard or a sequencer is often a step-wave, meaning that the voltage jumps
(or “steps”) from one voltage to the next as the notes are played. When this is patched into a VCO, the
result is a sequence of notes that jump from one pitch to the next. Adding in some slew causes the
Page of15 20

notes to “glide” from one pitch to the next. This effect is known as portamento or glissando. The Dual
EnvVCA can perform this effect by patching the step-wave into the Follow jack and taking the output
from the Env Out jack. The amount of glide effect is controlled by the rise and fall times. If you’re
patched into the pitch input of a VCO, you can adjust the tuning with the Level and Offset pots. Keep in
mind that the Dual EnvVCA is not designed to be a precision portamento effect, so tuning will not be
accurate over a wide range.
Creating ASR and ADSR Envelopes
ASR Envelope
An ASR (attack-sustain-release)
envelope is trapezoidal, with a rising
slope (attack), a flat plateau
(sustain), and a falling slope
(release). See Figure 7. The width of
the sustain stage is controlled by the
width of the gate input: holding the
gate high longer results in more
sustain. This is in contrast to an AR
(attack-release) envelope, which is
the triangular shape that results
from patching into the Trigger jack
or using the Cycle button.
One channel of the Dual EnvVCA
can be used to generate a variable
pulse width, and the other generates
an ASR envelope. Turn Channel B
Cycle on and patch the EOF output
to the Follow jack and the Trigger
jack, using a mult or stacking cable.
Patch an audio sound source into
the Audio In jack, and run the
Audio Out jack to a mixer or amp.
Make sure Channel A’s Cycle is off.
Set all four Rise/Fall switches to
Med. Adjust the sliders so that
Channel A’s sliders are lower (faster)
than Channel B’s. Now adjust
Channel B’s Rise and Fall sliders to
control the overall tempo, and the
Rise slider alone to control the
length of the Sustain portion.
Alternatively, you can use a keyboard instead of Channel B’s EOF jack. Patch the gate output into
Channel A's Trigger and Follow jacks. Tapping a key quickly will result in a staccato note, while holding
the key down longer will result in a longer note. Keep in mind that the minimum note length will always
be determined by Channel A’s rise and fall time parameters, no matter how short the gate input is.
Another alternative instead of the EOF jack or a keyboard, is to use the gate output of a sequencer that
has control over the gate length (pulse width). Setting longer gate lengths for certain notes will
emphasize or accent them in the sequence. If you don’t have pulse
width control on your sequencer, you could patch it into Channel B’s
Trigger jack and turn off Cycle.
This patch works because we patched the gate into both the Trigger
and Follow jacks. The Trigger jack ensures a complete envelope
will output even if the gate width is very short. The Follow jack
produces the sustain. If we had just patched a gate into the Trigger
jack, the envelope would start to fall once the peak is reached and
we would have no sustain. However, if the gate at the Follow input
is still high, the envelope will remain high, creating the sustain
portion of the envelope. On the other hand, if we had only patched
Page of16 20
Figure 7: ASR patch: Gate length
controls sustain length
Rise Fall
Rise Fall Rise Fall
Level
Rise Fall
Cycle
Follow Follow
Trigger
Time CV
Rise Fall
Time CV
EOR
In In
FallRise
Level
Offset Offset
Slow
Fast
Slow
Fast
Audio B
Out Out
Audio A
A B
VCA CVVCA CV
Trigger
B
EOF
ENV
OUT
ORA
Env
Out
Slow
Fast
Med
Slow
Fast
Med
Dual EnvVCA
A
Cycle on
Rise/Fall
switches to
Med/Med.
Channel A
Sliders to
taste
To mixer/
output amp
From sound
source
Cycle off
Channel B
Rise sets
Sustain time.
Rise+Fall
sets tempo

into the Follow jack, then a short gate width would only produce a complete envelope if the rise time
parameter was very fast. Gates that are more shorter than the rise time will result in an envelope that
doesn’t reach the peak, as seen in Figure 6 of the previous section. However, by patching the gate into
both the Trigger and Follow jacks, we get complete envelopes regardless of the settings, as seen in
Figure 7. Notice the width of the pulses and how they correlate to the sustain of the envelope output.
The first pulse is not wide enough to produce any sustain because its width is lesser than the time it
takes for the envelope to rise.
ADSR Envelope
An ADSR (attack-decay-sustain-release) envelope is like an ASR envelope, except that it adds a fourth
stage known as “decay” after the attack stage. After hitting the peak, an ADSR envelope “decays” to a
sustain level less than the peak level. See Figure 8.This sustain level and the speed at which the
envelope decays are controllable.
We can generate an ADSR envelope with the Dual EnvVCA by feeding a gate into Follow. The gate
should be generated by an external module such as a keyboard or sequencer that lets you control the
pulse width. The pulse width determines the length of the sustain, that is, the ADSR envelope will do
the attack and decay segments and then hold at the sustain level until the gate goes low. At that point
it’ll do the release segment.
Use a mult or stackable cable to patch the gate signal into Channel A’s Trigger jack and Channel B’s
Follow jack. (The diagram above shows it also going to Time CV, but ignore that for now). Patch Env
Out B to Channel A’s Follow jack. Both Cycle buttons should be off. You can take the ADSR envelope
out from Channel A’s Env Out jack, and/or you can run audio through Channel A’s Audio In/Out jacks.
Page of17 20
Rise Fall
Rise Fall Rise Fall
Level
Rise Fall
Cycle
Follow Follow
Trigger
Time CV
Rise Fall
Time CV
EOR
In In
FallRise
Level
Offset Offset
Slow
Fast
Slow
Fast
Audio B
Out Out
Audio A
A B
VCA CVVCA CV
Trigger
B
EOF
ENV
OUT
ORA
Env
Out
Slow
Fast
Med
Slow
Fast
Med
Dual EnvVCA
A
Cycle off
Rise adjusts attack
Fall adjusts decay
and release times
To mixer/output
amp
From sound source
Channel B Level controls
sustain level
Fall CV adjusts
decay time relative
to release time
Gate (pulse width
controls sustain
period)
Cycle off
Rise and Fall sliders
and switches to Fast

Set Channel A’s switches to Med and set sliders two or
three marks above Fast. Rise will control the attack time,
and Fall will control both the release and decay times.
Channel B is configured as a follower with fast rise and
fall times, which essentially makes it pass the incoming
gate out of the Env Out jack. We can control the
amplitude of the gate output using the Level knob. We
then feed this variable-amplitude gate into Channel A’s
Follow. As we’ll see below, its amplitude sets the sustain
level. Note that the Level knob is sensitive and the patch
only works if it’s between 12:00 and 3:00.
Firing a gate will generate an envelope as shown in
Figure 8. The rising edge of the gate will trigger Channel
A because it’s patched into the Trigger jack. This causes
the envelope to rise to its peak and then begin to fall for
the decay stage. When it reaches the level on Channel A’s Follow jack, it will hold for the sustain
segment. The level on the Follow jack is controlled by Channel B's Level knob, thus the Level knob
controls the sustain level. After the gate on the Follow jack goes low, the envelope will fall back to zero
during the release stage, at a rate determined by Channel A’s Fall slider and switch.
We now have control over the attack or rise speed (Rise slider/switch), sustain length (gate pulse
width), and sustain level (Level knob). However, the decay time and the release time will always be the
same, set by the Fall slider/switch.
To make this a true ADSR envelope, patch a cable from the mult or stacking cables on the gate output
of the keyboard or sequencer to the Time CV jack. Make sure the keyboard/sequencer gate output still
goes to Channel A’s Trigger jack and Channel B’s Follow jack. Now you can use the Fall CV knob to
set the decay time relative to the release time. Turning it to the left of center will make the decay time
faster than the release time, and vice-versa. The reason this works is that the decay stage occurs while
the gate is high, and the release stage occurs when the gate is low. Since the gate is patched into the
Time CV jack, the position of the Fall CV knob only has an effect on the time when the gate is high,
which is the decay stage. Note that adjusting the Fall slider or switch will change both the decay and
release times.
For some exotic envelope shapes, try flipping Channel B’s switches to Med and adjusting the sliders to
slow down Channel B’s Rise and Fall times.
Generating Exponential and Logarithmic Envelopes
The Dual EnvVCA can be used to generate exponential and logarithmic shapes by patching Env Out
back into the Time CV jack. The Rise CV and Fall CV knobs can be used to independently control the
shape of the rise and fall portions. Turning the knob to the left of center will make the shape more
exponential, and turning it right will make it more logarithmic. Notice that the rise and fall times change
dramatically when using this technique, especially if the Rise CV or Fall CV knob is set higher than
3:00. The waveforms in Figure 9 were generated using this
technique (and by setting the Rise/Fall sliders differently for each
envelope).
Page of18 20
The Shaped Dual EnvVCA
module from 4ms Company is
the bigger cousin of the Dual
EnvVCA. This module has an
exponential and logarithmic
wave shaper, which can alter the
wave shapes without changing
the envelope timing.
Figure 9: Log and expo shapes generated by patching Env into Time CV and
adjusting Rise/Fall CV knobs
Figure 8: ADSR. Offset knob turned down in 2nd
envelope to lower sustain level. Fall CV turned up
in 3rd envelope to make decay slower.

Using Offset and Level Knobs
The Level and Offset knobs control the amplitude and DC level of the signal output from the Env Out
jacks. They do not effect the VCA or the audio signal (unless you patch Env Out to VCA CV). Being
independent of the VCA allows you to modulate something with Env Out and control the modulation
with Level and Offset without disrupting the VCA.
The Level knob controls the amplitude of the envelope. When the knob is centered, no envelope will be
output. Turning it to the right of center makes the envelope rise upward in voltage and fall downward
(this is the most common setting for an envelope). If you turn Level left of center, the envelope will be
inverted: it will rise downward and fall upward. The farther from center (in either direction) that you turn
Level, the greater the amplitude. At fully clockwise or counter-clockwise, the amplitude will be about
10V.
The Offset knob shifts the envelope output up and down. With the Offset knob in the center, the
envelope will rest at 0V and then rise to the voltage set by the Level knob (at most +10V if Level is fully
clockwise, or -10V if Level is fully counter-clockwise). If Offset is turned left of center, the envelope will
rest at a negative voltage. When Offset is fully counter-clockwise, it will rest at -10V. Going the other
way, if Offset is turned to the right of center, the envelope will rest at a positive voltage, with +10V
being the maximum.
The Env Out jacks clip at about -10V and +10V. Using Level and Offset at their extremes, you can
easily cause clipping which results in a steady -10V or +10V output (and is not typically very interesting
in a patch). If you’re ever unsure where to set Level and Offset, a good starting place is to set Offset
to the center, and Level to around 3:00 or higher.
RETRIG Jumper
The RETRIG jumper on the back of the module changes the Dual EnvVCA’s
behavior when it receives a trigger while an envelope is already running. When
the jumper is not installed (factory default), triggers received as the envelope is
rising will be ignored, and triggers received while the envelope is falling will
make it begin rising again from its current voltage.
When the jumper is installed, the Dual EnvVCA will immediately restart the
envelope when it receives a trigger, regardless of whether the envelope
is rising or falling. When this happens, the envelope will immediately fall
to 0V and begin to rise again. This sharp transition to 0V can cause
clicking when used with the audio VCA section.
See the Creating Envelopes section on page 13 for more details.
VCA Min Gain Trim pot
On the back of the module is a trimpot that can adjust the minimum
VCA gain. Typically, you will want to set this so that you do not
hear any audio bleeding through when the envelope is not running.
However, setting the minimum gain too quiet means that when the
Dual EnvVCA is cycling, there are longer gaps between notes.
That is, there is more time between envelope peaks where the
sound is inaudible or barely audible.
At fully counter-clockwise, the VCA will provide -90dB of
attenuation when the envelope is not cycling. This is the maximum
amount of silence between notes when cycling and minimum amount of bleed. In the middle position
(factory default), there is -80dB of attenuation. It provides a short amount of silence between envelope
cycles, and low amount of bleed. Turning the trim pot all the way clockwise provides -30dB of
attenuation when the envelope is stopped. This may be useful if you wants less silence between cycles,
and don’t mind hearing some audio when the envelope is not cycling.
Page of19 20

Electrical and Mechanical Specifications
•Dual EnvVCA
•16HP Eurorack format module
•0.95” (24mm) maximum depth (includes power cable)
•10-pin Eurorack power header
• Power consumption
•+12V: 156mA max
•-12V: 131mA max
•Audio/VCA
•100k input impedance, 1k output impedance, DC-coupled
•VCA gain range: -90dB to +0.9dB
•DC to 20kHz, +/-0.1dB
• Envelope Times
•Minimum rise or fall time: ~62.5us (8kHz max frequency)
•Maximum rise time: > 10 minutes (typically > 13 minutes)
•Maximum fall time: > 20 minutes (typically > 40 minutes)
•Jacks:
•Env jack: Min = -10.2V, Max = 10.1V
•Envelope: Max amplitude = 9.3Vpp
•Trigger jack: rising edge threshold = 2.5V
•Cycle jack: rising edge threshold = 2.5V
•Follow jack: active range = 0V to +5V
•EO* jacks
•EOR (channel A): <80mV low to >4.50V high gate output
•EOF (channel B): <80mV low to >4.95V high gate output
•Minimum stable pulse width: 1ms. Shorter than this may produce extra 50µs pulses
•Audio In/Out jacks: <-10.0V to >+10.0V maximum range without clipping
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