Noise Gate

Good evening, I’d like to introduce a very simple custom unit: Noise Gate! This unit was modeled on the disting “L-8 Gate” algorithm and parameter ranges. With apologies to os I will let him explain the functions:

The outputs are muted unless the input signal exceeds a threshold level.
The Z knob/CV sets the threshold, with a range of approximately 0-8V.
The outputs are muted by an envelope, triggered by the input signal rising above the threshold level.
Parameters 0-2 set the attack, hold and release times of the envelope. The hold time is the minimum
amount of time the envelope is considered to be triggered. The approximate time ranges for each
parameter are: attack 10ms-1.8s, hold 0-600ms, release 45ms-8s.
Parameter 3 sets a lookahead time, effectively delaying the audio slightly relative to the trigger
detection. This can be used to ensure that sharp transients are not lost during the attack time of the
envelope. The maximum lookahead is about 10ms.

In my unit the “lookahead time” is called Lag for brevity. The envelope follower’s input is linked to the unit input by default.

Please let me know if you have thoughts about your usage or potential improvements!

noise-gate_v2.unit (16.5 KB)

EDIT2: Release control fixed!

EDIT3: Noise Gate v2 released for v0.4+. Now works with no reconfiguration needed! Unit input signal is used for key signal by default.


“Release” now correctly controls the gain envelope.

I’m having a lot of fun using drum loops to gate other audio!


hello i’m new to the er-301 and a noise gate is one of the things i wanted to be able to create, though i’m struggeling to patch it internally and your .lua doesn’t seem to want to work on my unit, maybe you could help? i’m not asking for the finished noise gate but more how you did it so i can reproduce it and learn at the same time :wink:

Good question! I’ll have to dig into how I did it cause it’s been awhile. In the meantime try renaming the .lua to a .unit file. I think that’s the new extension? This was patched on a v0.3xx firmware but should be compatible. You’ll need to dive into the unit and adjust the source (aka key) for the gate action. I think by default it is hooked to Input 1.

thanks for your faszt answer!
so i’ve changed the .lua into a .unit and it works! i’ve adapted the input 1 to my actual input but i still don’t get it haha i’ve tweaked the unit main parameters but can"t seem to have any changes in the sound,
i know i’m not doing it right as it always is when you can’t make something work in eurorack, but another round of help would be most welcome haha

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I just uploaded a v2 I apparently made months ago. Now the unit uses its own input signal for the envelope follower vs. threshold comparison, so no reconfiguration needed. For easy results, just slowly crank the threshold up until it starts dropping the quiet bits. Then tweak follower parameters to taste!

If you want to do trance gating, etc, by using an unrelated signal as key input, it’s still very easy through internal rerouting but I will probably release a separate unit for that.


i’ve only tried it today and it’s awesome, i’ll take some time to understand it, thanks a lot!

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This is a great little unit!!
I’ve been having issues with lots of noise from various modules going into the 301 (nothing related to the 301) & casually thought a noise gate would solve many of these … Hey presto, a quick search, and here we are!!!
Many thanks!!

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