VG2

Dual Passive Low-Pass Vactrol Gate

VG2 is a Dual Passive Vactrol Gate. No power needed! Each Vactrol Gate has 1 CV Input (gate, envelope, LFO, etc.), 1 Audio Input and 1 Audio Output. The CV Input hits the Vactrol LED, allowing audio to pass through. In addition, there is a simple Low Pass Filter applied to the Audio Output with an Amount (Cutoff) knob. As this is a passive circuit, it will not give you full cutoff control, but it does allow the taming of harsh waveshapes. The LPF is simply the same concept as a guitar’s “tone” control. Also, there is an LED at the CV Input for quick visual reference and LED light action!

One thing to keep in mind with a passive circuit using a vactrol is there may be varying differences between each vactrol. One may be slightly “louder” than the other, or have a longer release time or shorter release. These are variations that are inherent with vactrols and can usually be adjusted with a powered circuit, but not with a passive circuit. But, this adds a bit of variation to each vactrol gate making each output unique. It may be found that one output is better for percussive sounds and one is better for melodic sequences. There may also be no noticeable variations at all, but this is part of the vactrol charm and why we love them so much! Each Vactrol supplied is hand-selected by Laurentide SynthWorks. The descrepincies are bleed when silent & top output level. We try to pick vactrol’s that have little or no bleed when no CV is applied and that they all have a similar output level, so you won’t have to worry about one being waaay quiter than the other.

As this is a passive circuit, it is advisable to use a Buffered Multiple before the CV Input to maintain voltage/amplitude, especially if you are using the top CV to drive both gates.

https://www.laurentidesynthworks.net/vg2.html