Linear/Exponential VCA


Linear/Exponential VCA

I’ve been playing around with Softube Modular recently (can’t afford a real rack :frowning: ) and the Doepfer A-132-3 module included has 2 linear/exponential VCAs. I found the layout and linear/exponential switch handy so I thought I would make something similar for Audulus. Rather than modulate the knob directly I’ve included a separate mod input. The gain knob is intended as a static gain. It’s exponential and calibrated in dBs. The static gain goes from -120 to 3dB. The mod input has an attenuator and a switch for linear or exponential response. With the mod attenuator at 50% a mod input of 1 results in unity gain (0 dB) and with the mod attenuator at full, a mod input of 1 results in 2x output (+6 dB)


Input Signal Range Notes
in audio -1 to 1 or modulation 0 to 1 signal to be attenuated or amplified

Output Signal Range Notes
out 0 to +9 dB max modulated signal


Control Function Notes
mod level control for mod input range from 0 - +6dB
gain `sets the static (no mod input) gain for the module -120dB to +6dB


Meter Displays Notes
gain display displays static gain in dBs

Version History

Revision File Date Notes
1.0 linear-exponential VCA V1.0.audulus (12.7 KB) 05/20/2019 initial upload


Revision File Date Notes
1.0 linear-exponential VCA V1.0 demo.audulus (32.3 KB) 05/20/2019 initial upload