A impression of the Moog Ladder Filter made from the YuSynth schematic. This filter uses two CA3046 transistor arrays which are matched transistors in a DIP14 package.
The filter is fed a squarewave from a Thomas Henry VCO-555 and on the CV-1 input there's a short pulse from an AD/AR which in turn is triggered by the gate pulse from the sequencer.
Complete instructions on how to build this filter on stripboard, and for many other modular synthesizer related projects can be found on my website:
https://www.eddybergman.com