This is an interesting one which I developed a few years ago when I was reading about how compressors actually work.

Here we are working with 3 VCA´s. Insert the inverter in the control line between the envelope follower and VCA1 (upmiddle). Set VCA1 fully on (gain=10). The audioline from VCA1´s output is patched into VCA2 (downright). Do also set VCA2´s gaincontrol to maximum level 10.

The env. followers envelope-output controlling both VCA1 (via inverter) and a low cost VCA. The inverter will reverse the CV-value coming from the envelopefollower and lower VCA1´s output. Furthermore, the low cost VCA will open up letting ADSR´s controlvalue get through to VCA2 (via inverter).

Producing a good effect, feed the evelopefollower with some punchy percussion sound. The more you turn the envelopefollowers gain control up there will be a resultant fall in the output of VCA1 and VCA2.