[sdiy] Buchla 295 10-band comb filter topology

[Lanterman, Aaron D]

Does anyone recognize the topology Don is using here in the bandpass sections?

http://fluxmonkey.com/historicBuchla/buchlaFiles/Buchla_2950_200.jpg

The low and high bands are 3-pole Sallen-Keys, but I’m not sure what’s going on in the middle filters. It looks kind of like a multiple feedback filter, but instead of having a resistor to ground like in Figure 1 here:

https://sound-au.com/project63.htm

There’s some weirdness with a 3rd capacitor connecting to the resistive feedback back.

Aaron Lanterman, Prof. of ECE, Georgia Tech
My blog on Education and Innovation: https://edupocalypsenow.wordpress.com
My blog on Electronics and Programming: https://lantertronics.blogspot.com
My YouTube channel on Electronics and Programming: https://www.youtube.com/c/lantertronics



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