Reaktor 6 Envelope Follower

How to create an envelope follower in Reaktor 6 Primary and set your synth to automatically follow the amplitude of drums.


An envelope follower is a device that converts the amplitude envelope of an audio input into a control signal. Once we have that control signal, we can use it to control whatever we want. We can make the amplitude of an oscillator follow the amplitude of the input, or we could move the cutoff frequency of a filter, panning, etc.

Building the envelope follower is rather straightforward, just two steps: of rectifying and then low-pass filtering. In this video I walk through the process, and then show a few different applications.

More Reaktor 6 intermediate tutorials here.

Bidirectional OSC in “Baion 倍音” with Kyma & Unity3D

Talking through bidirectional OSC (Open Sound Control) in my 2018 piece Baion (倍音), that I perform on a custom-built interface, “the catalyst”.

I’m performing my 2017 piece “Baion” this week, and I thought it was a good chance to revisit some of the mechanics of the piece, specifically the communication between the different elements–the custom interface, the Kyma timeline, and the game built in Unity3D. In this video, I go through how the musical work emerges from the bidirectional OSC communication between software.

More videos on Symbolic Sound Kyma here:

Pd Comb Filter Patch from Scratch

Building a comb filter in Pure Data Vanilla from scratch.

A comb filter is a filter created by adding a delayed signal to itself, creating constructive and destructive interference of frequencies based on the length of the delay. All we have to do is delay the signal a little bit, feed it back into itself (pre-delay), and we get that pleasing, high-tech robotic resonance effect.

There’s no talking on this one, just building the patch, and listening to it go.

0:00 Playing back a recorded file
0:35 Looping the file
1:00 Setting up the delay
2:08 Frequency controls for the filter
2:52 Setting the range
3:48 Automatic random frequency
4:25 Commenting the code
5:39 Playing with settings

More no-talking Pd patch from scratch:

Artificial Neurons and Nonlinear Mixing

Talking through the concept of an artificial neuron, the fundamental component of artificial intelligence and machine learning, from an audio perspective.

I’ve made a few videos recently with “artificial neurons” including in Pure Data and in Eurorack, and, in this video, I discuss the ideas here in more detail, specifically how an artificial neuron is just a nonlinear mixer.

An artificial neuron takes in multiple inputs, weights them, and then transforms the sum of them using an “activation function”, which is just a nonlinear transformation (of some variety).

Of course just making a single neuron does not mean you’ve made an artificial intelligence or a program capable of “deep learning”, but understanding these fundamental building blocks can be a great first step in demystifying the growing number of machine learning programs in the 21st Century.

More music and sound design with artificial neurons:

Reaktor 6 Primary Sequencer

I set out to make a tutorial about making a simple sequencer in Reaktor 6 Primary, and got way too long-winded, so this first part is just about making a low-pass gate (LPG).

A low-pass gate is a low-pass filter that is functioning as a VCA. When it isn’t triggered, the filter’s cutoff frequency is subaudio, not letting any audio pass. When triggered, though, the cutoff frequency goes up, letting all frequencies through. In analog, too, this motion of the cutoff frequency is performed by vactrols, adding a quick attack and release that some compare to the sound of bongo.

In this video, I make a digital LPG, talking through the best numbers for an effective result.

0:00 Let’s make a sequencer!
0:54 Making our usual sawtooth synth
1:24 Explaining a low-pass gate (LPG)
2:06 Starting with a low-pass filter
2:35 AR envelope
3:01 Modifying the envelope
4:25 Multiplication
5:14 Subtraction
6:12 Switching to 1-pole filter
7:26 Resonance (not usual for an LPG)
8:21 Talking through the macro

Part 2, where I actually make the sequencer, here:

Part 3 here:

Zoomscapes Updates

For the last few years, I’ve been messing around with internet-based, no-input feedback loops in collaboration with Will Klingenmeier.

What does that mean? Why would I do that? What does it sound like? All those questions are answered in the brief PechaKucha below:

Zoomscape Pecha Kucha – Understand it all in less than 8 minutes!

While I’m sure we’ll continue to mess with these ideas in the future, we’ve come to at least a short-term culmination of this project in a tape release of these experiments on bandcamp.

You can also retroactively join our “Tape Release Party” here:

Zoomscapes Tape Release Party from 2/5/23

To catch up on all of the previous experiments, check out this playlist:

Pure Data Interactive Hardcore System (Pd Vanilla Interactive Drum Machine)

A Pure Data interactive system that plays hardcore drumbeats when it’s not receiving any audio input.

At the start of winter break, I wanted to make some music and burn off some steam. The “Interactive Hardcore Music System” was the perfect solution for both. Here, I talk through the Pure Data patch explaining how it works and how I’ve used it, and waxing philosophical about how things don’t need to be complicated to be sophisticated (and musically expressive).

Get the “Benjolin Synthcore” album on bandcamp:

More Pure Data Tutorials on YouTube:

0:00 Intro/What is this thing?
1:41 Input section of the patch
4:30 Interaction with Logic Pro X
4:53 Compression as secret sauce
6:03 Creating the beat (probability gates)
7:34 The results
8:13 Other examples
9:25 Closing: Sophisticated ≠ Complicated

Pure Data Clamping VCA with [clip~]

Creating an ambient music machine in Pure Data Vanilla with a “clamping VCA” that adds subtle distortion, imitating the envelopes in Roland TR-808.

I made a clamping VCA in Reaktor a few weeks back, and now here’s another example in Pd. Normally, amplitude envelopes in synths are a control envelope on the amplitude of the signal. When we use a “clamping VCA”, though, instead of controlling the amplitude of the waveform, we clip it at the desired maximum envelope. This means, when the VCA is all the way up, it sounds the same, but during the attack and release, we’ll get the addition of subtle (or perhaps not-so-subtle) distortion to our waveform.

I use [clip~] in Pd to achieve this effect, stealing the idea from Noise Engineering’s “Sinclastic Empulatrix” module, which, in turn, stole the idea from from the Roland TR-808 drum machine’s cymbal envelopes.

More Pure Data Tutorials: