How to convert a 24dB lowpass VCF to 12dB multimode?

[CoreInside]

https://github.com/JoeEarlam/GMSNPure/b ... %20VCF.sch

hi, im looking for an open source design for a multimode analogue filter with bandpass, high pass, and low pass, also notch if possible. how difficult would it be to convert this gmsn open source 24dB filter to a 12dB multimode filter? i always wondered why GMSN never designed a multimode. is it because it's difficult to design? also if anyone knows of an alternative open source multimode filter please let me know.

[EATyourGUITAR]

that circuit already has 2 pole and 4 pole output with a master resonance (Q) control. HP = input-LP out the phase is important. you can also write this as HP=input+(-LPout). where - indicates phase reversed phase 180 inverted signal etc...

band pass is a bit more stuff. over my head at the moment. here is some information to get started.

https://electricdruid.net/multimode-fil ... e-filters/

[KSS]

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