This Module is discontinued.
4 Channel Comb Filter
A bandpass filter with sharp cutoff slopes (20 dB/octave) at crossover frequencies of 250, 1000, and 4000 Hz. Individual filtered outputs are unattenuated; summed output has adjustable spectral shape.
http://www.buchla.com/historical/b200/294-4chanfilter.html
Included in 90 Racks, 41 are public: