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Envelope Generator (ADSR) block for ADAU1701

Question asked by MaxAudioDSP on May 9, 2016
Latest reply on May 15, 2016 by KJBob

Hi Guys,


an Aida DSP user builds analog synthesizers, he is curious about

the possibility to use ADAU1701 to realize some of the common blocks found in popular old analog synths.

One of the building blocks is the ADSR, I've found an excellent documentation about it here.


I know for more powerful processors (like ADAU144x which is supported by Aida DSP library) have Signal Envelope

block available, but for the smaller ADAU1701 there isn't.

The block needs six inputs:

  • Gate In
  • Trigger In (optional, to retrigger envelope after attack is complete)
  • Attack duration
  • Decay duration
  • Sustain duration
  • Release duration

And one output

  • Audio Envelope Out


Anyone has an idea on how to do it from scratch in Sigma Studio? I'm thinking about realizing time constants (capacitors) with first order low pass filters, but I don't know if there are other ways so I'm asking the community.

The final project and Arduino sketch will be available to the community here and on github.


Thank You