VCA clicking

When using a VCA + ADSR combo with an external audio input and trigger it with a gate I get a very loud clipping noise every time the VCA triggers. What I do is to assign an input, then add a VCA and then inside the VCA unit I add the ADSR. Is this right ? When I do the same feeding an analog envelope to an analog vca it doesn’t happen, so I guess I’m doing it wrong ?

Thanks guys

How much are you modulating the VCA level parameter with the ADSR? Sounds like you have the modulation gain cranked up too high, perhaps?

I trigger the VCA with a gate and inside the VCA I add the envelope, that’s the way I’m doing it. It’s probably wrong because the gain amount attenuates or increases the clipping but it doesn’t disappear

Is the signal already clipping before the VCA?

The source is normally a raw oscillator so I don’t think it’s clipping

Do you mean the click?

That’s the nature of super fast envelopes - this is a good thing!!

Try adjusting the Attack and Decay portions of your ADSR, a few ms on each should get rid of the click!

Oh. Are we having a terminology problem? Clipping means that the tops of the wave are being flattened. A click is usually caused by a discontinuity in the waveform like (that in the saw or square wave).

Oh okay, so it is the snappiness of the envelope :slight_smile:

I guess I wanted the extreme snappiness but not the clicking :wink:

Yeah it’s a click, not clipping. When the signal is further processed it does sound like audio clipping though

In that case @anon83620728’s suggestion is the way to go.


This is something that when it’s done right is incredibly useful and can sound amazing!

It’s not the easiest of things to work with though because of the way the envelope interacts with the sound. When you’re using envelopes of a few ms there is often a disparity between where in the cycle the sound waveform signal is and when the envelope opens… sync can help but it’s the sound source that matters most in my experience.

I’d love to hear more hints and tips about working with very short envelopes and working with the clicky if anyone has any :slight_smile:

I have observed that triggering the VCA with a sine wave pulse makes the click fade smoothly, seems obvious … But then the snappiness is not as extreme.

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Exactly, do the same thing with a pulse and things can get crazy!

Edit, oh I misread, I thought you meant the incoming signal!

What do you mean with a pulse ? Sorry :smile:

A square wave!

Yeah that’s how I was doing it initially, therefore the loud click. Sorry but is a pulse a square wave only ?

Interesting, I’ll have to try that!

I also had some great results from sending feedback from the envelope to itself - specifically the Attack and Decay portions, but this requires dedicating the envelope to it’s own channel on the ER-301.

At one point it really sounded almost like a vactrol!

See here for some more details, you might find what you are looking for there!

I find a helpful way to think of it is that a pulse is a variable width square wave!

Thanks I’ll take a look on that thread !

I am finding the Pamela’s New Workout one of the most useful modules in my system. You can send square, sine, ramp and random waveshapes from it, or even feed it CV and then spit it through​ it’s outputs !

I see pulse as :

2- a single vibration or short burst of sound, electric current, light, or other wave

Ahh yes, I see… you’re not wrong, but for the purposes of discussions re. synthesis it is a technical term that means something quite specific in this domain:

Thanks for the clarification !

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Here is a diagram depicting the typical VCA+ADSR topology. Hopefully it helps make sure we are all on the same page.