Randomizing decay on an oscillator/drums?

Downloaded Rack like an hour ago with no experience in modular and am wondering how i would randomize decay on drums or something because i think that would be pretty cool. I’ve heard you can randomize triggers pretty easily with a bernoulli gate but i don’t know how i could get the sound i want with randomized CV. pls help


You may use Vult Slap or some kind of envelope generator and VCA together and just take for example VCV Random module and bring the same trigger (or not exactly the same) from your playing instruments and then take the random output and bring into Decay or release parameter of your chosen envelope generator.

1 Like

You need to patch a noise/random signal into the decay’s cv input. The problem is this will “randomize” it constantly. You want to randomize it only when you trigger the drum hit.

This is where “sample and hold” modules come to the rescue. The basic idea is that they accept an input to be sampled (a noise signal in this case), and a trigger that triggers the sampling.

Whenever you trigger them, they will sample whatever is coming in at that moment (from the noise input), and output that value until they get triggered again, in other words they will hold the value.

Now if you trigger sampling with the same trigger you use for your drum, you’ll have different decay on every hit.

S&H modules even have their own category in the library so youll find many that can do this. The one I like the most for it’s simplicity is this…

Also, Sample+Hold is your friend: without an input to hold, it generates random voltages per trigger. The one from Mockbar Modular is maybe the best choice as you can fine tune the range and it has probabilty.

(oh, haha, well this above, while I was typing :slight_smile: )

I see it’s been mentioned a few times already, but yeah Sample and Hold (often written S&H) modules are perfect for making random CV values . I often use S&H to randomize the decay of my HiHats :slight_smile: .

An easy way to make Hi hats in modular is White Noise -> VCA (with level modulated by an enveloppe) and then use your S&H to modulate the decay of your enveloppe.

If you wish a screenshot example, let me know ! Should be pretty fast to set up :wink:

I’m an idiot and delay was autocorrected to decay. I assume the same concept still applies though? Also, if anyone could provide a screenshot of what a patch with randomized delay looks like that would be great.


There’s a couple of ways you can randomize delay.

Send pulses to the tap tempo input using something like a turing machine or a Bernoulli gate on a clock. Send a random voltage from a sample & hold to the delay time input.

1 Like

Hi Otter, and welcome to the forum!

There are many parameters that can be modulated, randomized on a delay. Some will make sense others not, and some will make more sense creatively when randomized in sync with a clock assuming the delay is synced as well.

Maybe this mini tutorial I made a while ago, might be of help to you or inspire you to explore:

Just replace the VCV Router with a free switch if you don’t have the VCV Router. Alternative switches: Fundamental Switch, Bogaudio Switch. Etc.

Hope this helps!

1 Like