MXR envelope follower..?how works?

[WeAreAs1 at aol.com]

In a message dated 11/29/98 3:56:48 PM, you wrote:

<<The mystery is, how do you make an envelope follower wah with 
6 amplifiers, a couple diodes, two CMOS switches.>>

Here's how:  It's a switched capacitor filter.  The switching frequency is
controlled by the input signal's rectified amplitude.  I have an original
schematic of it floating around somewhere, but it might take a few days to
find it.

This unit sounds remarkably good on guitars (very nice distortion that
occurs)... not so good on synths (the distortion is not so pleasant, for some
reason).  A lot of the distortion artifacts it creates are a result of its
very crude half-wave rectifier.

Michael Bacich