Available as an assembled Module and as a DIY project.
No info about availability.
State Variable Filter (1U)
The SVF in our 1U 'filter core' format.
This is a two pole multimode filter capable of high pass, low pass, band pass and notch output modes. All four outputs are available simultaneously. This new version of the very popular Oakley design is based around the classic two pole state variable filter topology as used in a variety of vintage synths including the Oberheim SEM and OB-X. At high resonance the Oakley SVF will oscillate over the whole of the audio band and is temperature compensated.
The design is intended to fit into a 1U wide 'filter-core' module.
These merchants probably sell this module. Huh?