/diy/ - Do It Yourself

Hey /ohm/, I'm doing this pedal effect for my Analog Circuits class. It's an inductorless wah-wah pedal. The circuit is pic related. The linear pot is for modulating the effect. The log pot is for volume.

I have to explain theoretically why/how it works. I know the wah wah effect is produced by a variable bandpass filter. If I had used the version with the inductor, it would've been easy to explain (here's an explanation on how it works for reference: http://www.geofex.com/Article_Folders/wahpedl/wahped.htm).). But this inductorless version is a bit tricky and I have no idea how/why it works.

I'd appreciate any help.