Programming Sines - Three Different Approaches

Programming Sines - Three Different Approaches

By its nature, Sines is a unique combination of traditional synthesis parameters combined with some unusual oscillator parameters and ways of making the oscillators interact that might not be obvious at a glance. After using Sines for a while, it became clear that there are a few different ways a user might approach programming sounds. The good news is that with its all-controls-visible-at-once user interface and oscillator oscilloscopes, it's easy to get your head around and quickly make all manner of nifty (and dynamically variable) racket!

Approach #1 - Stacking Sine Waves

Generally known as "additive synthesis," the concept is that much like prime numbers, any audible sound can be synthesized by combining sine waves at different pitches and amplitudes. Over the years a few commercial synthesizers have utilized additive synthesis (notably the Digital Keyboards Synergy and the Kawai K5), but additive never really took off, because it can take a lot of sine waves (and thus a lot of programming) to create complex sounds. With that said, there's one VERY popular synth that exclusively used additive sine waves: the venerable Hammond B3/C3 tone wheel organ, which generated a whole bunch of sine waves via mechanical tone wheels spinning in a magnetic field, and allowed control of their levels via drawbars.

Thus you might not guess by looking at it, but Sines is capable of making bang-up organ sounds. It might not seem as if four oscillators creating sine waves would offer many tonal options, but remember that each oscillator includes an adjustable sub sine wave (one octave down) and super sine wave (one octave up), so it's really like having 12 individual sine wave oscillators. Although each of these waves isn't individually tunable, this isn't a big limitation in use, because you'll typically want the sine waves tuned to standard even harmonic series intervals, such as octaves, fifths, major thirds, or minor sevenths. The Templates>Harmonic Series factory preset is an excellent starting point - oscillator 1 contains root notes, oscillator 2 contains fifth intervals, oscillator 3 contains higher root notes, and oscillator 4 contains dominant seventh intervals. Many tonal colors can be achieved with different combinations of the main oscillator Level sliders along with the Sub Osc and Super Osc level sliders. (For those of you using Cherry Audio's Voltage Modular, the Harmonic Series patch is essentially a recreation of the Buchla-inspired Additive Oscillator module.)

The Filter section can also be used, but if you're using pure sine waves, there isn't much content to filter, so the filter will behave largely as a volume control for harmonics.

Finally, there's nothing stopping you from using the oscillator waveshaping controls to alter and enrich timbral content, but remember that the waveshaping controls only affect an oscillator's primary waveshape; the Sub Osc and Super Osc waves are always going to be pure sine waves.

Approach #2 - Standard Subtractive Synthesis (With Mondo Oscillators)

If you've already begun creating sounds, you're probably already using Sines this way, that is, as a four-oscillator synth running through an analog-style filter. The good news is that if you're familiar with standard analog synths, you don't need to know much more - just twist the Feedback, Phase, Width, Shape, Wavefold, and Drive knobs until you land on something you like and treat it like any other analog synth. Because Sines oscillators don't have controls for directly creating analog-style waves, here are some tips for nailing classic analog oscillator tones:

• Sawtooth/Ramp waves- To "bend" a sine wave into a saw or ramp wave, simply crank up the Feedback knob in either direction. If you'd like a little more high-frequency "hair," rotate the Width knob clockwise from center, or add some Drive (or hey, do both, we're all in show business here!). The waveform won't necessarily look correct on the oscilloscope, but it will sound authentic (and remember that the waveforms from some of the classic analog synths look pretty funky when you actually view them on a scope!).

• Square and Pulse waves- Spot-on square and pulse waves can be created by turning the Shape knob fully to the left and the Drive knob fully to the right. The Width knob will function just like a standard analog synth pulse width control, and pulse-width modulation can be created by modulating the Width knob using an LFO (click Src>LFOs>LFO 1), and turn up the small mod amount knob to around 25%.

• Triangle waves- Starting with a pure sine wave and turning the Shape knob up to around 12-15% results in a waveform very close to a traditional triangle wave.

• Oscillator Sync- Like a lot of other Sines sounds, we accidentally discovered a great way to nail analog sync sweep-type tones. Any combination of oscillators can be used, but for this example we'll use Oscillators 1 and 2:

  • Set Oscillator 1 coarse pitch to 4'.

  • Set Oscillator 1 Phase mod Src to Oscillator 2 (click Src>Oscillators>Oscillator 2)

  • Set Oscillator 1 Phase mod Via (click Via>Envelopes>Envelope 3)

  • Set Oscillator 1 Phase mod amount around -6%

  • Turn Oscillator 1 Drive knob all the way up.

  • Set Oscillator 1 horizontal Level slider almost full up and Oscillator 2 Level slider to zero.

  • Set Oscillator 2 coarse pitch to 16'.

  • Set Oscillator 2 Feedback knob all the way up.

  • Set Envelope 3 Attack at zero, Decay around 4000 ms, Sustain at zero and Release at zero.

• White Noise- A very pure white noise tone can be achieved by modulating oscillator phase using the output of the same oscillator. Suffice to say, the nice thing about this is that you don't have to burn up multiple oscillators. For this example, we'll use Oscillator 1:

  • Set Oscillator 1 Phase mod Src to Oscillator 1 (click Src>Oscillators>Oscillator 1)

  • Set Oscillator 1 Phase section mod amount knob all the way up or down

Approach #3 - Phase Modulation / DX-type FM Synthesis

With its four oscillators, phase modulation between oscillators, and ratio tuning increments, Sines absolutely nails classic Yamaha DX-style "frequency modulation" synthesis. We know a lot of folks get stomach cramps, clammy hands, and other non-specific symptoms when the topic of FM synthesis arises, but trust us, it's relatively easy with Sines (and SO much easier than an 80s synth with up/down buttons and a tiny numeric LED display). Before we go any further, allow us to clarify perhaps the largest nomenclature foul-up in the history of synthesis...

FM synthesis is short for "frequency modulation synthesis." On the most basic level, FM synthesis uses one oscillator running at an audio frequency ("modulator") to modulate another oscillator ("carrier"). If you've ever used a low-frequency oscillator to modulate the pitch of another oscillator for vibrato effects, it's exactly the same thing, except that the modulation oscillator is running at a much higher frequency. Because it's running at such high speed, the resulting audio isn't heard as vibrato, but as a change in overall timbre.

The Boring and (Sort Of) Important History of Frequency Modulation vs. Phase Modulation Synthesis

Using an oscillator running at audio rates to modulate another oscillator makes some nifty sounds but the result is somewhat inharmonic in nature; that is, it inherently sounds a bit sour and out of tune. Great for space lasers, not so great for "Saving All My Love For You." The big spoiler is that Yamaha FM synths don't generate sound via true FM synthesis - they actually use phase modulation instead. Phase modulation is roughly similar, but instead using an audio-rate sine wave to modulate an oscillator's pitch, phase modulation modulates the carrier oscillator's phase relationship to the modulating oscillator.

The best analogy would be to think of frequency modulation as moving the carrier oscillator up and down, whereas phase modulation moves the carrier oscillator from side-to-side, shown in the diagram above. The important takeaway is that phase modulation sounds much more in tune and musical, and offers a wider timbral range.

Why Yamaha didn't refer to their revolutionary synthesis as phase modulation (or PM) remains a mystery of the ages, but Sines is capable of both true frequency modulation synthesis and phase modulation, so you can try each for yourself and see what we're talking about.

From here on out, we'll refer to this DX synthesis thing as "phase modulation synthesis."

Phase Modulation Basics

Generally speaking, there were two "levels" of Yamaha FM synths - "four operator," and "six operator," often abbreviated to "four-op" and "six-op." An "operator" is just another word for an oscillator, so a four-op synth contained four oscillators, and a six-op synth contained six oscillators. Naturally, a six-op synth (i.e. DX7) was capable of more elaborate sounds than a four-op instrument, but in reality, the two extra oscillators usually didn't make that much difference.

These oscillators were arranged into various configurations where some would be modulators (like a real fast LFO) and others would be carriers (sound sources). These configurations are called "algorithms." In some algorithms, most of the oscillators would be carriers, in others, modulators were stacked with other modulators, etc. If you've ever seen a DX instrument, the little icon diagrams across the top was a "cheat sheet" showing the configuration of all available algorithms; four-op instruments had eight algorithm choices and most six-op instruments had 32. As you may have guessed, certain algorithms lend themselves to different types of sounds, but the good news is that you can get a lot of mileage out of just a couple of algorithms - in fact, you can get a heck of a lot of different sounds by just modulating one oscillator with another.

Phase Modulation Synthesis with Sines

"Are these clowns ever gonna tell us any useful information!?!?" Stay with us, we're getting there! We'll take this in two steps: first we'll show how to create a knucklehead-simple one-oscillator-mods-another-oscillator "two-op" phase modulation synthesis, and then we'll haphazardly toss you into the digitally abyss of all eight standard four-op algorithms.

In our basic phase modulation patch, we're going to set up Oscillator 2 (modulator) to modulate the phase of Oscillator 1 (carrier).

Click the New button in the upper-left corner to initialize Sines
Click the Src button above Osc 1's Phase section, and select Oscillator 2 (Src>Oscillators>Oscillator 2)

At this point, if you hold a note and turn the little Phase mod amount attenuator, you'll hear something that sounds very much like a DX7. Instead of manually twirling the knob to and fro, let's modulate the amount of Oscillator 2 phase mod with an envelope generator:

Click the Via button above Osc 1's Phase section, and select Envelope 3 (clickVia>Envelopes>Envelope 3)
Set Oscillator 1 small Phase mod amount knob around 12%
Set Envelope 3 Attack at zero, Decay around 2400 ms, Sustain at zero and Release at zero

Aaannnd it's 1983 all over again... we told you DX synthesis was easy! Now try playing around with both oscillators' Ratio controls - a cavalcade of classic DX goodness awaits. If you find something you like, use the Utility button above the oscilloscope to copy Oscillator 1 to Oscillator 3, and Oscillator 2 to Oscillator 4, pan Oscillator 1 hard left and Oscillator 3 hard right, and dial in the Drift knob (in the bottom right Master section) to taste. Instant stereo FM fwangery.

Shown above are the eight algorithms available in vintage four-op DX synths. Each colored box represents an operator (i.e. an oscillator). The green operators boxes on the bottom are carriers (sound generators), and the red boxes on top are modulators (mod oscillators affecting the timbre of carrier oscillators).

You'll find patch templates for all eight algorithms in the Templates preset folder. These are strictly intended as starting points. Instead of using the Phase knob mod controls, all of the oscillator phase mod routings have been configured in the Mod Matrix. This is because algorithms 2, 3, 4, and 6 route a single modulator to multiple carriers, which isn't possible using the mod boxes above the panel knobs.

The important controls you'll want to play with are the Ratio knobs, and the Mod Matrix Amount knobs, which determine how much modulation signal gets to the carrier oscillators. We've set the mod Amount knobs to 10% in the templates, but you'll most likely want to modulate their depth by configuring envelope generators in the Via slots. If you run out of envelope generators, remember that LFOs set to One Shot mode can be used to create simple envelope generators (particularly the various permutations of saw and ramp waves).

As you're checking out the various algorithm templates, also notice that the oscillator Level sliders in each template correspond to the green carrier oscillators in each template: green=audio source (Level slider turned up), red=mod source (Level slider turned down).