who never dreamt about a tube wah ? whell, there’re some circuits on the internet, most of them use the “bridged-T” filter topology. A twin T filter in the feedack path of a gain stage.
I decided to dedicate 30 min of my time on this. Not bad sounding but, once again, really subtle but useable. This advantage of this over a more complex filter is the need of only one variable pot. which can be replaced with a photo-coupler . The 47K pot used for the 1st tube grid leack resistor acts like a “depth” control . Not really necessary in my opinion.
by the way, in regard to this low value a buffer (yes the “B word” ! ) is necessary. Otherwise the filter may sound weaker.