This video, via Roberto Raineri-Seith, demonstrates the Moog 907A Fixed Filter Bank (with inductors) from a System 15 modular system.
The 907A Fixed Filter Bank is a vintage Moog modular design that features a lowpass, highpass, and 8 bandpass filters. They are not voltage-controllable. The combination of lowpass and highpass filters at the extreme ends and bandpass filters in the middle allows for fine control over which frequencies are allowed through the filter.
The demo features 2 Moog 921b oscillators (32′ and 16′ rectangular waves) with various FFB tweaks.
The second video, below, demonstrates each individual bandpass output in progressive order (frequencies: 250, 350, 500, 700, 1000, 1400, 2000, 2800 Hz) to show their individual characteristics:
Delay (TC Electronics D-Two) and reverb (Vermona DSR-3) added.