Envelope follower Gate/Trigger output

Hi everyone, I have another basic utility request: which unit or combination of units would produce a gate/trigger from an audio threshold value? So: when audio exceeds a certain set threshold, a gate would be produced, and preferably also a short trigger. I hoped to find this in the Envelope follower because I’m used to Mutable Instruments Ears doing this. In fact, if I have one meta-request for the ER-301 @odevices then it would be units producing gates and triggers at interesting moments (like the envelope follower, ADSR, etc). I don’t think I have seen this anywhere in the basic units so there must be a good reason for this absence of functionality, even though I believe I have seen @NeilParfitt asking for a similar behavior in the scale quantizer unit somewhere. A unit can have only one output I guess, so extra feedback is hard to implement. Would this require a complete paradigm shift in how the firmware functions? It’s just, stuff like EOC and EOR on Maths and all that is some of the most useful data for creating dynamic, self-generating patches and I would love to see that coming to the ER-301.


Without actually sitting in front of the unit, I’d try something like

signal–>env follower–>adsr–>skewed sin env–>limiter

If I recall correctly, the adsr has a threshold control, but the skewed sin env doesn’t. The skewed sine env when fed into a limiter with the pre-gain cranked and hard limiting can be shaped nicely into a trigger signal though. You might be able to eliminate the skewed sine and just use the ADSR. But I vaguely remember doing something very similar and seemed like it worked better with both in series.

Hmm… everything that has a trigger in the ER-301 has a comparator built in as part of the input branch, just set the threshold high enough to only trigger when the audio input reaches whatever level you want it to trigger at. I’m not sure this really behaves in the same way as a dedicated unit though?? Might be worth a try!

EOR EOC can be hacked in similar ways in global chains… kinda! It’s not exactly that comfortable though, e.g.

Chain 1 = envelope routed to wherever in your patch
Chain 2 = output of Chain 1 sent to the trigger input on a sample player with threshold set to the highest point of output from Chain 1 to play a recorded trigger.

But yes, I agree that some kind of more advanced routing system would be awesome, but lets not forget it’s not a CV computer, it’s a sound computer with some very cool cv options!

I would really recommend using an external function generator like Maths if you want this kind of thing :slight_smile:

Thanks guys! I just posted to the Scorpio thread with a little recording experiment I made using this information :slight_smile: Scorpio - bespoke unit - available for download now!

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Just pop open my Noise Gate custom unit and take a look…


also missing a gate out on the env follower, but for sure there is plenty of options to build it in the ER…
Will anyway check out desolationjones noise-gate (hope it works on 3.25) - but could this tip from odevices in the scala thread maybe also do the trick?

"Just pipe the output of the Scale Quantizer through a high pass filter (*) such as the Fixed HPF and set the trigger threshold of the envelope’s input so that it triggers correctly.

(*) High pass filters are simple edge detectors."

My Noise Gate unit was composed on v3.2x so it should be good to go. It has an input within the VCA subchain where you can pick which audio source is connected to the envelope follower (default is IN1), and it is great fun to point something else in there. I like to gate pads using complex drum loop samples :slight_smile:

I will rewrite this unit soon for v4.x. The new local routing options will enable me to make the default behavior much clearer to the user by connecting the unit input to the envelope follower. This will introduce a frame of delay but the “lag” control should help make up for it!


Does noisegate work in the latest firmware?