LinguaeDevices: Dual Passive Lowpass Gate - 4hp Eurorack Module

A dual, passive, lowpass gate!

Ins/outs:

-Audio input.

-CV input.

-Audio output.

~~~~Circuit Function~~~~

-The audio input sees a light dependent resistor.

-This LDR is optically coupled to a green LED - which is driven by the CV input. As the current into the LED increases, LDR resistance drops, the filter cutoff ascends, and signal attenuation is reduced. - Amplitude and filter cutoff are coupled to one another. Creating an organic decay quality.

- Intensity control, adjusts current into the LED - The same is true for the trim control, which is meant to set a resistance floor. They are both 50k, Intensity is log, Trim is linear.

-There is a 4x4 capacitor bank, with selections via dip switch. This allows 15 different capacitance values for the low pass filter ~ as well, when all switches are null, the circuit acts purely as an optical attenuator.

Capacitor values are staggered, roughly exponential - to ensure a lack of redundancy through the various combinations - and a range that extends by more than an order of magnitude.

***For the CV input - The LED is protected from reverse bias, with a schottky.

CV input accepts 0v-10v.

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Included with order:

- Power Cable

- M3 Mounting Screws.