4U031 - '73 VCF

4U031 - '73 VCF This is the very first filter, that was introduced in the paperface era, know as the R12 VCF. It is a state variable, 2 pole, 12dB/oct LP, HP, 6dB slopes on the BP, it does not self oscillate. The circuit consists of a voltage processor, allowing the filter frequency to respond either proportionally or inverse-proportionally to the incoming CV. The output of the voltage processor is then fed to a pair of exponential converters that control the gain of the CA3080 transconuctance amplifiers in the filter core, thus varying the frequency. This version has all the well know mods, like an LED for visual feedback and also the trigger (ping) input. PCB: 1.6 mm thick, double sided, green base material FR4-Standard TG 135-140 surface finish HASL part values are silkscreened all panel mount! Front panel 1.6 mm, PCB material with colour front print that "mimics aluminium" 2" x 175 mm mounting holes - 3.5 mm, follows the LW specification (top and bottom) please note, minor imperfection may occur no parts, just the PCB and panel Documentation