Thomas Henry PAL VCF

3320 based VCF with Phase Shifter, All Pass Filter and Low Pass Filter capabilities, hence its name

Introduction (With the words of Thomas Henry) :
“What, another filter? Yes, and there's a good reason for it. When it came time to design a filter for my synthesizer, I was struck by how many exotic designs already existed - phase filters, polygonal filters, multimode filters, and filters which did everything but clean the sink. On the other end of the scale there were noisy filters, trashy filters, worthless filters, and filters which hardly filtered at all! What I wanted was a good quality, middle of the road filter -and this design is the result. […]
Theme PAL came about because depending on how you adjust the controls, you can have a Phase shifter, All pass filter, or Low pass filter. In addition to the usual voltage controlled options, this unit also features voltage controlled resonance.”
(Thomas Henry 1982)

Features :
* CEM-3320 (AS3320) based 4-pole 24dB LoPass filter,
* CV input with attenuator,
* CV input for 1V/Octave,
* CV input with attenuator for resonance,
* Coarse and Fine tuning pots,
* Mode switch (lowpass/allpass).

http://www.fonitronik.de/index.php/download_file/49/185