This module uses the same blackbox technique as the Shat-noir Phaser.
The VCF is based on the Steiner diode VCF but this one uses LDRs rather than diodes and a CV control system to suit. The nice thing about this filter is you can feed different signals to the LP, BP & HP inputs then surf between them with your CV, quite different from regular filters.
The VCA is really there to use up a spare op amp and is based on the Korg PS3100 VCA, works very well for what it is.
PCB set = USD24
Panel = USD22
assembled = USD210
Build guide and other info on the NLC wiki