Why is an Attack/Decay prefab needed?
The stock ADSR module can be used as an Attack/Decay module, but it can under some conditions produce loud “pops and clicks” especially when used with a fast attack time (the so called exploding envelope bug). So far I have found no problems with this prefab with very short envelope attack times.
Third party modules required.
There are two third party modules required for this prefab, namely Elena’s ED Memory/Reset module, and Davidson’s DAM ASR module.
The Attack/Decay generator.
I used the DAM ASR module, but the module itself has a sustain built in after the attack segment is complete, and I wanted to go into the Decay (Release) segment immediately the peak of the Attack segment was reached.
To do this I used a comparator to detect when the ASR module reaches 6.9 V (this appears to be the maximum), this is then fed back to the ED Memory/Reset module which resets the Gate signal to 0V. I know this is feedback loop with it’s inherent latency, but the few samples worth of delay really doesn’t cause any noticeable issues with the operation.
The Curve plugs control the shape of the Attack and Decay segments individually, from a log curve, through linear to an exponential curve.
Attack and Decay timings use the same formula for the stock ADSR module’s Volts to Seconds timing conversion.
The first Level Adjust module is used to bring the AD envelope to the ususal 0 to 10 V range with the standard 0-10V slider control range.
Note: As with the standard ADSR using a slider range of -10V to +10V gives both normal and inverted envelopes.
