The Cat Girl Synth Utility EG is a very standard logarithmic response ADSR envelope generator.
This is a PCB only suitable for multiple formats
This module is a very standard logarithmic response ADSR envelope generator. It is not voltage controlled. It is for use where a basic envelope generator is adequate. There are two identical envelope generators on the PCB.
How to use this module:
Connect your external GATE signal to the Gate input. Adjust the pots as required. Rotating the pots clockwise will increase the time of any particular stage, or in the case of SUSTAIN increase voltage of the sustain portion of the cycle. The output is exponential due to the basic resistor/capacitor configuration used in the timing cycle.
A little on how it works:
The schematic of the Utility Envelope Generator.
IC1A is the GATE detector and is set to detect signals over about 2 volts. It's output falls when a gate signal is present. This turns off the RELEASE circuit and trips the ATTACK/DECAY bistable IC1D. This "bistable" is actually a schmitt trigger that also servers as the peak detector for the ATTACK period.
IC1C is the output buffer. It follows the voltage on the main timing capacitor C. Its signal is fed back into IC1D. When the ATTACK peak voltage is reached (approximately 5V when running from +/-15V power rails) the bistable resets, shutting off the ATTACK circuit and turning on the DECAY circuit.
The DECAY circuit discharges capacitor C until it reaches the voltage set by the SUSTAIN pot.
When the GATE input goes LOW the bistable is set, if it hasn't already been set by other circuit elements, ready for the next ATTACk cycle, and the RELEASE circuit is turned on, and discharges capacitor C.
Brand | Cat Girl Synth (CGS) |
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Additional Resources | BOM & More Information |