[sdiy] Wondering about function generators for envelopes

[Grant Richter]

We already did that.

It's called a Blacet Mini-Wave, a very practical arbitrary function  
generator. Which very many people already own.

Take your "vanilla" (preferably linear) ADSR and process it through  
the Mini-Wave on the 0 to 10 volt range.

This converts each envelope segment into a 256 step sequence of  
voltages with adjustable "playback" time for each segment. An  
adjustable slew limiter after the Mini-Wave allows you to convert  
multi-segment sequences in multiple "sub" envelope sequences and will  
remove any 8 bit "zipper" stepping.

The "Socket Rocket" PROM contains a large range of variants of  
exponential and anti-exponential (logarithmic) envelope curves. These  
are the m to a power banks.

To get fancy, use the gate voltage to change Bank or Wave between ADS  
and R sections. For really fancy, bring out the attack latch bit from  
the ADSR and sum with the gate signal to change segments between A to  
DS to R. Or route one to external Bank input and one to external Wave  
input.

There are a number of Banks which contain multiple events (4089 pulse  
bank for example and Morse code bank). These pulses when processed  
with the following slew rate limiter produce multiple "sub" envelopes  
from one A and/or D and/or R section. This sounds like strummed  
envelopes (ala Subotnick).

For echo effects, multiply (with DC coupled VCA) the original ADSR  
envelope with the processed/slewed envelope to get echo release type  
envelopes (DA-Da-da-da).

Modular synthesizers are VERY versatile and creative new applications  
for existing modules can save money and time.