What I want to achieve is individual Attack/Release controls for several channels of a drum synth (which, for many reasons including the fact I'm still a shitty coder, is leaning more towards being analog in nature), and also to provide a pitch EG where required. In my mind's eye I pictured having a board built up to host all the EG circuits, with the various gate outputs collected together on a header to go off to all the VCA/VCO control inputs.
This looks reasonably simple and buildable, and although I don't have any TLO74s I do have plenty of TLO81s which look like they might be a suitable substitute. Should I be looking at something else or is this circuit worth building and experimenting with?
Ahh slight trail-of-thought fail in my original post The outputs from that circuit are supposed to feed into the CV input of one of the various voltage-controlled amplifier circuits I have coaxed out of Google - I haven't decided which one to build yet but the simplest one seems like a good place to start!
The one thing I can't figure out just by looking at the envelope generator schematic is whether or not the attack level will ALWAYS eventually go up to the maximum, or does it's max level depend on the peak voltage of the trigger pulse? Might be one of those "build it and see" things... if the output level is proportional to the input (e.g. for a very basic sort of velocity sensing on a trigger pad), then I'm in business. If not, then I'm stuffed and need something else.
is whether or not the attack level will ALWAYS eventually go up to the maximum, or does it's max level depend on the peak voltage of the trigger pulse?
No there is nothing that suggests it will always go up to a maximum, it is DC coupled throughout so the output is eventually going to be function of the input.
To have it always increase I would expect to see a capacitor in the feed back loop of one or more amplifier, in other words an integrator.
The outputs from that circuit are supposed to feed into the CV input of one of the various voltage-controlled amplifier circuits I have coaxed out of Google - I haven't decided which one to build yet but the simplest one seems like a good place to start!