WHA-FILTER
http://www.fortunecity.com/tinpan/humperdinck/223/whaf.htm

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This wha-filter design is based on Morley Power Wha-filter. I made a modern design around it with op-amps.
I've built it in a PAIA volume pedal which has a huge swing! Gives me plenty of excercise!
The sound is a bit'dark' with a fat accent,unlike the LDR(original) version,which sounded more mellow!
I've used a negativ log 470k pot but you can use a 100k to 1Mlog
In my pedal the pot attatchment is reversed to a Crybaby for example so i have to use
a negativ logaritmic pot....annoying!
Use a wire wound pot instead to get rid of any scratch! 
Modifications:

There are a few.
Things changes! Now i use a controler to swich between 6 capacitors for different tunings
The values are: 10nf, 8.2nf, 6.8nf, 5.6nf, 3.3nf, 2.2nf
This works good if you also decreases the filterpot to 10kohm. Now my whasound is better then ever before!
Increasing the 1Mohm resistor (second op-amp) to 2.2 or higher increases the Q value
If you feel that the sound is to muddy you can get more treble by changing the 220k resistor at the output by lowering the value
I advice you to use a 100k trim instead of the 220k resistor
The schematic below is going to be updated with the above suggestions in the future
Here is the schematic 
With a 250k pot in serie with the second op-amp before the 1.8M resistor it's possible to change the filter's sharpness(Q-value) Not used in my version though!