DOEPFER / A-179-2 Light Controlled CV Source

Variations

The A-179-2 is a controller module that generates CV/Gate signals according to the intensity of "illumination. A “LDR = Light Dependent Resistor” is mounted on the “Sensor” in the upper left corner of the panel, which internally converts light into an analog voltage for output. A remote sensor can also be connected to the ext. Sens. jack using a standard patch cable instead of the built-in sensor.

The A-179-2 comes with an external sensor (A-100C200) with a 2 m patch cable. The external sensor is mounted on a small printed circuit board with a 3.5 mm jack socket. The socket has a nut for mounting the external sensor.

The A-179-2 is similar to the A-178 Theremin Control Voltage Source. The difference is that it uses “illumination intensity” instead of “distance between hand and antenna” to generate the CV/Gate signal.

The A-179-2 allows the user to choose between “passive control,” where the sensor is covered or blocked by a hand or body, and “active control,” where the sensor is illuminated by a flashlight or smart phone light. Two types of CV output jacks (CV Out+ and CV Out-) are provided for these different uses.

Controls and I/O
ext. Sens.: An external sensor can be connected to this socket using a standard patch cable. When an external sensor is connected, the internal sensor is turned off.
CV Offset knob : Sets the reference value for the voltage output at a specific brightness. (e.g. if you want to output 0V in total darkness).
CV Level knob : This control is used to adjust the sensitivity of the generated CV signal (the effect of differences in brightness on the CV signal).
Gate Threshold knob: This control is used to adjust the threshold for generating the gate signal. An internal jumper selects whether the Gate signal is generated from CV Out+ or CV Out-.
CV Out+ : Positive CV output, the stronger the light, the higher the CV of this output.
CV Out-: A negative CV output, the stronger the light, the lower the CV of this output.
CV Out LEDs: Bipolar LEDs (red/yellow) are provided to indicate the CV output.
Gate : Gate signal output with LED indication.
Example of use
CV Out signal is used to control CV parameters of an external module. (e.g.: VCO pitch and pulse width, VCF freq. and resonance, VCA volume, envelope generator time, VCLFO freq. etc.
Trigger external module activity with the Gate signal that can adjust thresholds. (e.g.: envelope start, sequencer start/stop, switching functions (e.g.: connect and use A-150-1 or 151)).
CV signals can be converted to MIDI control change messages by connecting the A-192-2.

A-100C200 External sensor with patch cable (included in product)

Width 4HP
Depth 30mm
Current consumption
+12V : 10mA
-12V : 10mA