"Joe Meek" compressor secret

[Thomas Hudson]

Paul Perry wrote:

> Further, has anyone experimented with filter structures with
> grossly non-linear components, such as replacing resistors with
> resistot/diode combinations?
> 
Funny you should mention this. I spent this weekend looking at
guitar distortion circuits that use diodes either in the opamp
feedback path (TS909) or to ground (MXR Distortion+). On
Jack Ormans site (http://www.muzique.com/amz/index.html), 
he has an article (http://www.muzique.com/amz/latch.htm)
about putting a resistor in series with the two diodes in the 
opamp feedback path to reduce differences in using various opamps.

This led me to start thinking about the technique John Simonton
used in the 2700 series filters using diodes. I read an article 
online about this, but now I can't seem to find this article.
I am probably wrong on this, but wasn't it feeding current into the
diodes to change the cutoff of the filter? Anyone know where this
article and schematics are?

I am interested in varying the series resistance for each diode 
independently, hopefully producing different amounts of even 
harmonics in the distortion, possibly dynamically based on envelope.

Thomas