Let's Get Fenestrated (black panel)

triple window comparator

This module contains three individual window comparator circuits. They all work slightly differently from each other and somewhat differently from regular window comparators.

These are particularly useful circuits to create gate/timed events from chaos signals, or any other CV signal. It can also be used for pulse width modulation at audio rates, lots of good sounds to be found.

The rather grandiose names for each comparator came from a paper - Some Special-Purpose Comparator Circuits by H.K Verma. The actual circuits are different but two are inspired by the ones presented in the paper.

1. Special Comparison Instant – this is probably the most normal window comparator of the three. The pots can be used to set the high and low voltages between which the output gate will be high. You can also patch in CV signals to alter the high and low settings.

2. Comp for Concurrent Magnitudes – this will output a gate when the signal on Input 1 is compared against the setting of the SET/In2 pot. If no signal is on In 2 then the pot sets a fixed voltage, otherwise the signal on In 1 is compared with the amplitude of the signal on In 2, which can be attenuated by the pot as desired.

The extra feature of this circuit is the Level pot can set the gate level (up to 10V!) or you can patch a signal into the LEVEL input and create envelopes or bursts rather than gates.

3. Comp for Restricted Openings – this one has a pot (WIDTH) or CV control to set and change the gate width. In1 and In2 are summed together and compared with the level chosen with the SET pot.

Building is fairly simple, just be mindful to bend the LEDs slightly upwards to shine thru the windows from the bottom. It is good to use super-bright LEDs in this module as they have to shine thru the PCB panel.

https://www.nonlinearcircuits.com/modules/p/fenestrated