Musicians who are into sampling and digital synthesis have at some point likely heard of single-cycle waveforms. But outside of their proponents, they're relatively little known—and even less understood.
Single-cycle waveforms exist in a kind of gray area between sampling and synthesis, as the very brief snippets of sound can be loaded onto wavetable synths, sampling keyboards, hardware samplers like the Elektron Octatrack and Akai MPCs, or into a DAW's virtual sampler. When looped and used as an oscillator, their singular tones can be further shaped the same way you would a traditional oscillator. Think of them as unique alternatives to waveforms like triangle, sine, sawtooth, and square.
Below, we offer some more details on just what exactly single-cycle waveforms are. And for those interested in using them as part of their musical process, we show which hardware samplers and synths you can use, how you can find or make your own single-cycle waveforms, and how to approach processing these sounds.
What Are Single-Cycle Waveforms?
Single-cycle waveforms (hereafter, SCWs) are very short audio files containing one cycle of a waveform (one peak and one valley). Once loaded into hardware or software-based sampler synthesizers, SCWs can function as oscillators that can be sequenced, played, and sculpted as in a traditional analogue subtractive synthesis machine.
SCWs are related to wavetable synthesis, as found in Waldorf's synthesizers (Blofeld and Microwave I) and the Studiologic Sledge 2.0, amongst others. These synths scan wavetables (a series of sampled sounds) to generate sound. They can accept SCWs, but these samples become part of the machine's wavetables—thus, one wouldn't be dealing with a discrete single-cycle waveform.
Hardware Devices That Load Single-Cycle Waveforms
Hardware that accepts SCWs and uses them as discrete waveforms include keyboards like the Ensoniq SQ80, E-mu Emax, and Dave Smith Evolver. Samplers and grooveboxes like the Octatrack and MPCs mentioned above, as well as the Elektron Digitakt, Pioneer Toraiz SP-16 and other similar machines, are great for using and treating SCWs. If you don't want to drop a ton of money on some of these samplers or synths, a great budget option is the Korg Volca Sample, a digital sample sequencer that lets users load SCWs.
If you're curious about other machines that can use single-cycle waveforms, a brief internet search will yield several results. In the Eurorack world, for instance, the Mungo w0 oscillator module allows users to load "arbitrary waveforms" from SD cards in standard wav format. Outside of hardware, VSTs like Xfer Serum, Native Instruments Absynth, iZotope Iris 2, and Ableton Simpler can also use single-cycle waveforms.
Where to Find Sample Packs
By now many are surely wondering where they can find SCWs. A few notable sample packs are available.
Most immediately, thousands of single-cycle waveforms can be found on the website Adventure Kid, operated by the Swedish-based musician Kristoffer Ekstrand. A truly monumental library, it features 4,300 single-cycle waveforms, each painstakingly created by Ekstrand. The collection features sampled waveforms from the unexpected (birds) to the exotic (granular waveforms).
More pedestrians sounds, such as cello and acoustic guitar, are also included in the Adventure Kid pack. Downloading is free, but users are encouraged to make a small donation for Ekstrand's work.
Producer Void Vortex offers a smaller collection of 100 single cycle waveforms, each rooted to note C. When set to loop, like any SCW, they become an oscillator. He also produced a video tutorial for how to use the waveforms on an Elektron Octatrack.
SB-Six, another producer that has made his own video tutorial for loading SCWs onto an Elektron Analog Rytm crafted some great SCWs to coincide with the video.
The apparent motherlode of all single-cycle waveform packs can be found on the website Galbanum. Available for download at $39 USD, this collection features 25,000 single-cycle waveforms organized into 102 categories, and in a number of formats so that they will work with a wide variety of hardware and software-based sampler synthesizers.
Creating Your Own SCW Samples
The single-cycle waveform packs mentioned above are a reminder that musicians and producers can create their own. And there are several tools for those individuals looking to do so.
Darwin Grosse's SCW Editor, for instance, is a browser-based tool for creating SCWs. Users simply load samples into the editor, reshape the waveform with various parameters like frequency and bit depth, etc., then load them into their SCW-compatible hardware or software instruments.
For PCs only is the Audioterm editor. This tutorial shows how a user how to create SCWs using this editor, if you're interested in exploring this option. And Groovesizer describes how to craft single-cycle waveforms using Audacity with a pen tool. Audacity is compatible with PC, Mac and Linux systems, so this is definitely a versatile choice.
Sculpting the Waves
Once loaded into a sampler or wavetable synthesizer, loop the single-cycle wave. This will create a foundational tone that can be sculpted with synthesis techniques. From there, you can either play the SCWs chromatically with a keyboard or with a sequencer. The sequencer, however, will perhaps be the easiest way to get into processing the SCW. Because it's automated, a sequence will allow you to tweak synthesis parameters without worrying about triggering the sounds.
After a sequence has been programmed, either monophonically with the step sequencer or polyphonically with chords (if your sequencer allows it), begin treating the SCW as an oscillator. Tweak the filter's cutoff, resonance, and envelope via attack, decay, sustain, and release. Start playing around with the amp envelope's ADSR parameters. Use an LFO (or multiple LFOs) to automate modulation like filter sweeps, bit crushing, and so on.
The idea behind loading single-cycle waves into a sampler is to get creative and experimental with a sound source, so be creative and experimental with the signal processing, whether it be filtering, modulation, effects, or even sequencing.