MXR envelope follower..?how works?

[Rob]

Paul Perry wrote:
> 
> Looking at a poor copy of the original 1979 MXR envelope filter ckt,
> has a CD4016 quad switch and a CD4069 hex inverter.... and that's it!
> Presume the switches are used to make switched resistors for the
> filter, with the pulse width modulated by the signal envelope.... but
> I can't for the life of me see how any of it works.
> Any advice, comments , gratefully received.
> Also wonder how it sounds!
> If any good, it is a miracle of minimalism, and cheap to boot.
> 
> paul perry melbourne australia

yknow, you can use the hex inverter as an audio amp..This is prolly the
missing link you seek..
rob