a simple way to make a high-pass from a low-pass is to invert the low-passed signal and add it to the unfiltered signal. I guess this is exactly what the Doepfer Wasp is doing.
-- the-erc
Thanks @the-erc for explaining! This makes perfect sense. Good to know, that it's not a malfunction but a principle based behaviour.
@GarfieldModular Let's talk about tips and tricks for Mid/Side processing in Eurorack in another thread.