[sdiy] Decode between Decay phase and Sustain?

[Nils Pipenbrinck]

Grant Richter wrote:

> Has anyone seen a clever way to generate a logic bit at the end of  
> the the decay phase in an ADSR?
>
> A difference amplifier with comparator comes to mind. I wonder if I  
> am missing something obvious?
>
> Thank you. The application is a simple set of 4 LEDs, one each for  
> A,D,S,R.


There must be some kind of switching between the two discharge currents 
(decay and release) in the circuit. Maybe you can add a small current 
sensing resistor at one side of the decay pot and use a comparator to 
sense the decay?

Nils