Intellijel mVCA II User manual

µVCA Manual v1.00
µVCA II
Dual Voltage Controlled Amplifier and Cascaded Mixer

µVCA Manual v1.00
Table of Contents
Table of Contents
Overview
Features
Installation
Before Your Start
Installing Your Module
Front Panel
Controls
Inputs and Outputs
Instructions
Technical Specifications
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µVCA Manual v1.00
Overview
The µVCA II is a two-channel voltage controlled amplifier that features a response curve
continuously adjustable between linear and exponential response.
Features
●Continuously adjustable response curve between linear and exponential
●Gain trimmer with above-unity gain
●Dedicated CV attenuators
●LEDs for monitoring CV signal
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µVCA Manual v1.00
Installation
Intellijel Eurorack modules are designed to be used with a Eurorack-compatible case and power
supply.
Before Your Start
Before installing a new module in your case you must ensure your case’s power supply has
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 you have enough free space (hp)  as well as free power headers in
your case to fit the new module.
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. The pins are indicated with the label -12V, a white stripe next to the connector, the
words “red stripe”, or some combination of those indicators.
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µVCA Manual v1.00
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 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.
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µVCA Manual v1.00
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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µVCA Manual v1.00
Front Panel
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µVCA Manual v1.00
Controls
1. CV A - Sets the amount of attenuation for the CV A input. When fully clockwise the CV
input is unattenuated. When fully counter-clockwise the CV input has no effect. The
brightness of the LED to the right of the attenuator varies according to the level of the
resulting CV.
1. BIAS A - Sets the initial level of amplifier A before CV is applied. The maximum bias is
5V which provides a gain of 1.
2. EXP-LIN A - Sets the response curve of amplifier A. Linear when fully counter-clockwise
and exponential when fully clockwise.
3. CV B - Same as CV A but for channel B.
4. BIAS B - Same as BIAS A but for channel B.
5. EXP-LIN B - Same as EXP-LIN A but for channel B.
Note that prior to fall 2015 the BIAS and CV knob positions were reversed but their functionality
was the same.
Inputs and Outputs
A. CV A - Control voltage input for the level of amplifier A. Summed with the BIAS A
control. Voltages above 5 V will result in a gain greater than 1.
B. IN A - Input signal for amplifier A.  This is a direct coupled input so DC or AC signals can
be fed here.
C. OUT A - Output signal for amplifier A.
D. CV B - Control voltage input for the level of amplifier B. Summer with the BIAS B control.
Voltages above 5 V will result in a gain greater than 1.
E. IN B - Input signal for amplifier B.  This is a direct coupled input so DC or AC signals can
be fed here.
F. OUT B - Output signal for amplifier B.  As of the fall 2015 model OUT A is normalled to
be mixed into this output as long as nothing is patched in OUT A.  This means you can
use the module as a simple two channel mixer.
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µVCA Manual v1.00
Technical Specifications
Width
6 hp
Maximum Depth
35 mm
Current Draw
36 mA @ +12V
35 mA @ -12V
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