"Joe Meek" compressor secret

[Paul Perry]

In advertising for the (so-called) Joe Meek compressors,
it is hinted that there is something 'unusual' going on.
I suspect that the derived envelope used to control the 
compression may in fact be going through some kind of very
low frequency filtering/waveshaping network, say a 
notch around 10 to 30Hz.

Is this possible, is it likely, and what would it do?

Further, has anyone experimented with filter structures with 
grossly non-linear components, such as replacing resistors with 
resistot/diode combinations?

paul perry melbourne australia(going to bed, but keeping YOU
awake! perhaps)