When I saw it for the first time, it looked unfamiliar until I realized that RESPONSE is the EMS version of RESONANCE. Sadly there is no voltage control for resonance.
The unedited video is here:
This schemo is of the pre-'74 four-pole diode filter
Schematically, the Synthi ladder filter is very similar to the Moog ladder, except that Moog used transistors, and EMS used diodes. Another famous diode latter filter was made by Roland for their TB-303.
The audio enters via the matched pair of 2N5172 transistors at the base and exits via the two lines
above the group of 8 diodes.
I wonder whether this abundance of diode ladder filters is a direct response to Moog's dispute with ARP over their use of a transistor based ladder filter in their early 2600s.???
The response/resonance also effects the audio level a lot. ... it (loudness) can fall quite dramatically
as you approach the Resonance/Response's upper limits
Patch variation 1
Osc 1 + Osc 2 --->Filter + Osc2 ----> channel 2
Osc 1 + Osc 2 --->Filter ----->reverb ----> channel 1
The touching the keyboard triggers the Envelope which opens Channel 1's output.
Patch - Variation 2