2nd-order allpass VCFs?

[Paul Perry]

At 09:28 AM 23/11/99 -0500, Curtin, Steven D wrote:

>What's interesting about about many wah-wah pedals is that they don't vary
>the cutoff frequency of the filter, since this would be too expensive.
<snip>  I found this
>out when looking through the schematics on the web for such classics as the
>Crybaby.
>
I think the Crybaby & others actually vary *BOTH* freq and Q as you rock the
pedal.
And, the analysis isn't too easy for some of these..
Traditionally, the freq and Q increasse together.

paul perry Melbourne Australia