Analog transistor ladder low-pass filter, 10HP. Classic ladder topology with warm resonant character for leads, basses, and sweeps.

Filter – the soul of the synthesizer!..
This is famous analog filter for modular synthesizers, the scheme was created in the 70s by Robert Arthur Moog (Moog company, USA).

A characteristic sound, the same Moog fat!

This clone from OIIIAUDIO is built on transistors and using the chips of that time (!) And Stiroflex capacitors (optionally), which gives the sound a vintage charm and uniqueness (the initiates understand what it’s about).

https://oiiiaudio.com/products/transistor-ladder-filter