About the module

A Dual Low Pass Gate for Eurorack-format modular synthesizers. The dual audio channels are modulated through a mildly resonant, voltage-controlled low pass filter set up as a VCA. With a VCO as input, simple gate and trigger signals produce highly organic sounds.

Each channel is controlled through two light dependent resistors, resulting in smooth, musical response to control voltages. Control voltages can directly drive the filter, or gate signals can be routed to the 'pluck' input – essentially a gate-to-trigger converter – resulting in a quick burst of sound.

A third CV-controlled light dependent resistor is used inside the filter circuit to control depth and response time. Turning the 'dampen' knob shortens the multi-second response time and changes the filter tone, as if a hand was loosely placed on a resonating object. With a brief trigger, the filter can be rung out from a short pulse to over five seconds.

The module borrows heavily from the classic Buchla low pass gate. However, besides being completely open source, it adds the dampen control and pluck input, to allow for easier musical use and to better accommodate modern-day light dependent resistors available.

Product options

Available as a fully built module as pictured. Includes 13mm aluminum knobs, IDC power cable, and blue LEDs (note that mounting screws are not included). Aluminum wood composite panel with laser engraved labels and natural finish.

Also available as PCB only. Matte black PCB with ENIG finish. Uses 0603 passives throughout, but is otherwise hand-solderable for experienced builders.