This Module is currently available.
LFO controlling a VCA or Filter
If you follow electronic music, you are probably no stranger to the seminal band Throbbing Gristle. Formed in the shadows of the plague pits in the east side of London, the band both informed and defined the sound of industrial electronic music. One of the “secret weapons” of the band and a device responsible for some of the sonic mayhem was "The Gristleizer." This little circuit was originally designed by Roy Gwinn and published in Practical Electronic magazine under the name “Guitar Effects Pedal.” Chris Carter of TG made some modifications to the published design and the effect bearing his band’s name was born.
Now available commercially for the first time in 5U, the acGRISTLE seeks to recreate some of the timbres of this legendary effect. Both a VCA and VCF, the acGRISTLE has a built in LFO with four different waveshapes for creating all manner of ramped wah, pulsing tremolo, and audio frequency modulation. Available in its original configuration or as a deluxe version, with a variety of CV i/o and a unique gate input for further integration into the modern modular synthesizer landscape.
http://analogcraftsman.com/?product=gristleizer#tab-description
These merchants probably sell this module. Huh?