Serge Variable Slope VCF
The VARIABLE Slope VCF (VCFS) is unique is that the slope of the filter cutoff is variable manually or by voltage control from 6db/octave with little or no peaking to 12db/octave with noticable peaking at the cutoff frequency
Lowpass, bandpass and highpass output are simultaneously available and a small mixer allows 2 inputs to be manually mixed without using an external module
My Serge VCFQ was bought as a semi-kit from SMMS (Serge Modular Music Systems) in the early 1980's
I also built one with a PCB from Random*Source.
Random*Source currently don’t offer DIY options, though the module may be available from other sources
Info on the Random*Source module is HERE
Serge modules are available from these sources:
Random*Source: Serge Tcherepnin is the “Chief Innovation Officer” for Random*Source and they are currently producing classic modules and new designs. Currently there’s no DIY option to build thier designs.
Elby Designs: Ken Stone’s Serge boards are now available at Elby.
Prism Circuits: Serge Paperface modules are available to DIY. The focus is on early 6 row designs and the paperface build style.
Loudest Warning: Custom builds in Loudest Warning format and full panels. Panels are also available for DIY.