Available as an assembled Module and as a DIY project.
This Module is currently available.
Sharp Cutoff Filter Model 191 clone
Sharp Cutoff Filter Model 191 clone.
La Sesenta y Siete 191 Sharp Cutoff Filter Module is a voltage controlled highpass and lowpass filters with 24 db/octave slopes . Cutoff frequencies are variable from 5 cps to 20 kc with no range switching . Also functions as a bandpass filter with voltage controlled center frequency and bandwidth
These merchants probably sell this module. Huh?
Hofner 191
Bose 191 speakers
Bose 191 Speaker
ROH 191 Extended Range Audio Monitor
Dictaphone 191
Hofner 191