Intellijel Dual VCA 1U User manual

Dual VCA 1U
Dua/Stereo Linear Voltage Controlled Amplifier
Manual (English)
Revision: 2021.08.03

TABLE OF CONTENTS 
COMPLIANCE 2
INSTALLATION 3
Before You Start 3
Installing Your Module 4
FRONT PANEL 6
TECHNICAL SPECIFICATIONS 7
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Dual VCA 1U Manual 1

COMPLIANCE 
Dual VCA 1U Manual 2
This device complies with Part 15 of the FCC Rules. Operation is subject
to the following two conditions: (1) this device may not cause harmful
interference, and (2) this device must accept any interference received,
including interference that may cause undesired operation.
Changes or modifications not expressly approved by Intellijel Designs,
Inc. could void the user’s authority to operate the equipment.
Any digital equipment has been tested and found to comply with the
limits for a Class A digital device, pursuant to part 15 of the FCC Rules.
These limits are designed to provide reasonable protection against
harmful interference when the equipment is operated in a commercial
environment. This equipment generates, uses, and can radiate radio
frequency energy and, if not installed and used in accordance with the
instruction manual, may cause harmful interference to radio
communications.
This device meets the requirements of the following standards and
directives:
EMC: 2014/30/EU
EN55032:2015 ; EN55103-2:2009 (EN55024) ; EN61000-3-2 ;
EN61000-3-3
Low Voltage: 2014/35/EU
EN 60065:2002+A1:2006+A11:2008+A2:2010+A12:2011
RoHS2: 2011/65/EU
WEEE: 2012/19/EU

INSTALLATION 
This module is designed for use within an
Intellijel-standard 1U row, such as contained
within the Intellijel 4U and 7U Eurorack cases.
Intellijel’s 1U specification is derived from the
Eurorack mechanical specification set by
Doepfer that is designed to support the use of
lipped rails within industry standard rack
heights.
Before You Start 
Intellijel Eurorack modules are designed to be used with a Eurorack-compatible case and power
supply. We recommend you use Intellijel cases and power supplies.
Before installing a new module in your case, you must ensure your power supply has a free power
header and sufficient available capacity to power the module:
● Sum up the specified +12V current draw for all modules, including the new one. Do the same for
the -12 V and +5V current draw. The current draw will be specified in the manufacturer's
technical specifications for each module.
● Compare each of the sums to specifications for your case’s power supply.
● Only proceed with installation if none of the values exceeds the power supply’s specifications.
Otherwise you must remove modules to free up capacity or upgrade your power supply.
You will also need to ensure your case has enough free space (hp) to fit the new module. To
prevent screws or other debris from falling into the case and shorting any electrical contacts, do not
leave gaps between adjacent modules, and cover all unused areas with blank panels. Similarly, do
not use open frames or any other enclosure that exposes the backside of any module or the power
distribution board.
Dual VCA 1U Manual 3

You can use a tool like ModularGrid to assist in your planning. Failure to adequately power your
modules may result in damage to your modules or power supply. If you are unsure, please contact
us before proceeding.
Installing Your Module 
When installing or removing a module from
your case always turn off the power to the
case and disconnect the power cable. Failure
to do so may result in serious injury or
equipment damage.
Ensure the 10-pin connector on the power
cable is connected correctly to the module
before proceeding. The red stripe on the cable
must line up with the -12V pins on the
module’s power connector. Different modules
use different ways to indicate the -12V pins.
Some may be labelled with “-12V;” a white
stripe next to the -12V pins; the words “red
stripe;” or some combination of these.
Additionally, some modules may have
shrouded headers, thus preventing backward
connections.
Most modules will come with the cable already connected but it is good to double check the
orientation. Be aware that some modules may have headers that serve other purposes so ensure
the power cable is connected to the right one.
The other end of the cable, with a 16-pin
connector, connects to the power bus board of
your Eurorack case. Ensure the red stripe on the
cable lines up with the -12V pins on the bus
board. On Intellijel power supplies the pins are
labelled with the label “-12V” and a thick white
stripe:
If you are using another manufacturer’s power
supply, check their documentation for
instructions.
Dual VCA 1U Manual 4

Once connected, the cabling between the module and power supply should resemble the picture
below:
Before reconnecting power and
turning on your modular system,
double check that the ribbon cable
is fully seated on both ends and
that all the pins are correctly
aligned. If the pins are misaligned
in any direction or the ribbon is
backwards you can cause damage
to your module, power supply, or
other modules.
After you have confirmed all the
connections, you can reconnect the
power cable and turn on your
modular system. You should
immediately check that all your modules have powered on and are functioning correctly. If you
notice any anomalies, turn your system off right away and check your cabling again for mistakes.
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Dual VCA 1U Manual 5

FRONT PANEL 
[1] IN A - Input to VCA A.
The signal inserted here is amplified by
Voltage Controlled Amplifier A (at an amount
controlled by the CV A [3] input) and sent out
the VCA A out [5] jack.
[2] IN B - Input to VCA B.
The signal inserted here is amplified by
Voltage Controlled Amplifier B (at an amount
controlled by the CV B [3] input) and sent out
the VCA B out [5] jack.
IN A [1] is normalled to IN B [2] , so if nothing
is inserted into IN B , then IN A feeds both
VCA A and VCA B.
[3] CV A - The CV input for controlling the linear
amplification level of VCA A.
The input range is 0 V to 10 V. At 0 , no output appears at VCA A out [5] . 5 V results in unity
gain (meaning the voltage at VCA A out [5] is the same as the voltage at IN A [1] ). Voltages
above 5V increase the gain, with a 10 V CV input resulting in a maximum gain of +6 dB.
The amount of voltage present at CV A [3] is indicated by the brightness of the LED.
Common CV sources include envelope/function generators (for shaping the volume of the signal
patched into IN A [1] ) or LFOs (for generating tremolo effects).
[4] CV B - The CV input for controlling the linear amplification level of VCA B.
CV A [3] is normalled to CV B [4] , so if nothing is inserted into CV B , then CV A controls the
amplification for both VCA A and VCA B.
[5] VCA A out - The output of Voltage Controlled Amplifier A.
If nothing is connected to this jack, then the output of VCA A is mixed with the output of VCA B,
and sent to the VCA B out [6] jack.
[6] VCA B out - The output of Voltage Controlled Amplifier B.
If nothing is connected to the VCA A out [5] jack, then it outputs the sum of VCA A and VCA B.
Dual VCA 1U Manual 6

TECHNICAL SPECIFICATIONS 
Dual VCA 1U Manual 7
Width
8 hp
Maximum Depth
29 mm
Current Draw
37 mA @ +12V
40 mA @ -12V