That’s a really interesting question, but I’m drawing a blank if we have anything like that.
My recommendation is to check out this page if you haven’t
http://www.geofex.com/article_folders/ecftech/ecftech.htmIf you scroll down it has the input and envelope detector stage from the Mutron III. In my experience that one works great. But I also highly recommend checking out the Lovetone Meatball schematic which is based on the Mutron III with added features. IMO the most important added feature is the effects loop, which is an absolute game changer when it comes to incorporating an envelope in a pedalboard. Finally you can get Wah/______ after fuzz sound without the envelope detector being confused by added compression and harmonics