Build a Clavia Nord Lead with Reaktor 4

Sven Hermans

17 May 2005

Any comments are welcome, for contacting me use


This tutorial is an example of how you can build a synthesizer with Native Instruments Reaktor.

Table of Contents

1. Introduction
2. Starting somewhere
3. Oscillators
3.1. OSC 1
3.2. OSC 2
4. FM Amount
5. Sync
6. Mix
7. Untill now
8. Filters
9. Filter ADSR
10. Volume ADSR
11. Low Frequency Oscillators
11.1. LFO 1
11.2. LFO 2
12. Modulation Envelope
13. Nord Rack
14. Recommended reading

1. Introduction

To get the sounds you want you have to know how to build and create them. An easy and fast synthesizer to use is the Clavia Nord Lead. It's available with a keyboard or in rack version. The sound is excellent and it has many features, but of course not as many as you want. Only one thing to mention, mine has a limit of 4 voices, wich if you're playing chords with a long release time, you're stuck with a huge polyphony limit.

Let's simulate a Nord Rack in Native Instruments Reaktor.

Rebuilding an existing synthesizer probably won't give you a sound that wasn't created before because that's what the original does, but maybe it's a good way to get a better understanding of Reaktor.

First we have to know the specifications of the Nord Rack, so we have a basic thought of modules we'll have to use.

It has 2 oscillators.

  • OSC 1
    • waveforms: triangle, saw, pulse
    • FM Amount
  • OSC 2
    • waveforms: triangle, saw, pulse, noise
    • Keyboard Tracking on/off
    • Semitones setting from -60 till 60
    • Fine tune in cents
  • Other oscillator features
    • There is also knob for Pulse width modulation for OSC 1
    • Mix knob for the OSC 1 and OSC 2 levels
    • Sync button OSC 1 -> OSC 2

Knowing this, we can try to implement these features, step by step. Let's look further to get a global overview.

  • Amplifier
    • ADSR for the Volume Envelope
    • Gain knob to control overal output levels
  • LFO 1
    • Rate and Amount
    • Destinations: OSC1+2, OSC2, Filter, Pulse Width
    • Waveforms: Triangle, Saw, Random
  • LFO 2
    • Rate and Amount
    • Destinations: OSC1+2, Amplitude, Arpeggiator, Echo
    • note: Because Arpeggiators are a topic on their own, I'm not going to implement this feature. On the real Nord Lead I don't use it either anyway. The same goes for echo, rather built a dedicated Delay effect or use a plugin.
  • Modulation Envelope
    • Attack and Decay
    • Destinations: OSC 2, FM Amount
    • note: Instead of using a control which goes from negative to positive. I'm gonna use a positive control only in combination with a +/- switch.
  • Filter
    • ADSR to control the Filter Envelope
    • Envelope Amount
    • Filter Cutoff
    • Resonance
    • Keyboard Tracking On/Off
    • Filter Types: HP 24dB, BP, Notch, LP 24dB, LP 12dB

This seems to be a long list but at the end there are not so many knobs to control, as you would expect of today's software synthesizers. The main reaon why I've chosen to rebuild a Nord Lead is because it's very fast and easy to use. And, because it is capable to generate a huge range of different sounds. From strings to some UFO effect or even a bassdrum, when the Nord Rack is finished you can create those sounds within minutes.

I hear you wondering, will it sound as the original instrument? No, because our synth uses Reaktor's Oscillators, not those from Clavia. However, don't let this disappoint you, it sounds good enough. Remember that this simulation will be different from the original.. as said before, I'll skip the Arpeggiator part. Some other things too, ie. the Octave shift switches for the pitch. A poly/mono/legato switch too. Actually these are essential, but you can't get it all at once. Adding these later remains an option.

While learning Reaktor, there were situations that I got stuck. I had to go back several times and change things. This can be frustrating because most of the time there are a lot of wires. Disconnecting them, removing, changing and adding modules,... this can be an unpleasant task. Especially when you mess things up, even badder then it already was before, and forgot how it was connected in the first place. To avoid messing around, it won't hurt to think before you act. On the other hand, without trying things you will never know if it will work. What I'm trying to say is that you get in trouble anyway. Only saving your work regurarly helps you out. Of course you already knew this from other programs in general.. . Time to start building.

Disclaimer: Be careful when using Reaktor and try to keep the volume in your audio setup at a reasonable level, unless you are very sure that your sound won't do things you don't expect to happen. You can destroy your speakers or crash your computer, even both. Everything you do with this tutorial is at your own responsability. Also, this isn't the best or optimized way to built the synthesizer and I even can't guarantee it will work for you. This document actually isn't a tutorial and I recommend learning Reaktor from other sources. It mostly describes the path I went trough to eventually get the Nord Rack.