Analog Instrument

In by phoenixgreen

Ableton Live 10 - Software Instruments

Introducing the basics of synthesis

Analog is designed to emulate an analogue, subtractive synthesizer. An analogue synthesizer uses analogue electronic components, as opposed to digital ones, to create sound. In general, people like the sounds made by analogue synths as they are warm and often quite unique due to the fact that analogue components always have slight imperfections in their manufacturing. Subtractive synthesis is the most common type of synthesis found amongst analogue synthesisers and works by taking a tone from one or more oscillators, and then removing (subtracting) frequencies using a filter.

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A filter removes all frequencies below or above a certain threshold, which is commonly called a cutoff frequency. Filters will also feature resonance, which is a boost at the cutoff frequency of the filter.

Most subtractive synth designs will also feature one or more LFOs, or low frequency oscillators and one or more envelope generators. An LFO is very similar to the oscillators used to generate the tones, but they instead cycle at a slower rate and can be used to modulatevarious parts of the synth sound. For example, an LFO could be assigned to modulate the cutoff frequency of the filter, meaning that the filter will open and close in time with the LFO, creating a wah-like effect.

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An envelope generatoris similarly used to modulate various aspects of a patch and can be programmed to change over a period of time.

The most common type of envelope is an ADSR(attack, decay, sustain and release) envelope. ADSRs are very powerful for synthesis sound design as they allow sound to be shaped in interesting ways.

Attack – how long a note takes to reach full volume once the key is pressed

Decay – how long it takes for the volume of a note to drop from full volume to the sustain level

Sustain– the level at which a note will stay while the key is held

Release – how long a note takes to fade once the key is released

Analog’s interface is a central visual display, with panels arranged around it. The central display can be changed to show more parameters for each panel by clicking on that panel.  The global controls for analog can be found by clicking on the rightmost panel. Analog is special amongst analogue-style synths in that it features two filters and amp sections (most synths will only have one of each), and that these can be routed in various ways. To keep things simple in this lesson, we will feed both oscillators through a single filter and amp.

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The wave shape can be chosen in the oscillator section from the drop-down boxes. Each wave has a different sonic characteristic, so it is worth exploring each in turn. The three dials to the right will control the tuning of the oscillator, as will the envelope in this view. Each oscillator can also be used in sub mode or sync mode. Sub modewill blend a copy of the oscillator one octave down in. This gives is useful for making patches sound thicker and is particularly good for bass patches. Sync mode will restart the cycle of the oscillator to match a silent oscillator inside of Analog. The more that the sync percentage is increased, Analog will increase the difference between the silent master oscillator and the audible slave oscillator resulting in metallic sounding aliasing. This is very useful for creating harsh, harmonically rich patches such as bells.

Analog is routed like any normal subtractive synth in that the oscillators feed into the filters, which feed into the amp section. The oscillators, filters and amps all have independent envelopes which can be accessed by clicking on the corresponding panels. In Analog, envelopes can be set to either linear,or logarithmic.In practice, this just means that the slopes of the envelope are either straight (linear) or curved (logarithmic).

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There are two LFOs in analog, and each is assigned to the corresponding sections of the synth (LFO 1 can affect OSC 1, Filter 1, etc.). Each LFO’s shape can be changed to a different wave, and the speed at which the oscillator moves can also be set either to synchronise with a note value, or to a number in Hertz (cycles per second). To add LFO modulation to a parameter, click on the corresponding panel, and look for the percentage box which corresponds to the parameter which you want to modulate.

Tasks

Set up a session in Ableton and set your session tempo and time signature. Use analog to make a patch and record a short melody into Session view (four or eight bars). Save the set as “Ableton 10 Instruments” as we will continue to build on this throughout the course.

Quiz

Glossary

Analogue synthesiser: A synth which uses analogue circuitry as opposed to digital. Famous examples include the Moog Minimoog and the Sequential Circuits Prophet 5.

Cycle: A cycle is when a sound wave completes it’s motion and returns to the beginning of the wave. The amount of cycles in a second is measured in Hertz (Hz). Different musical notes can be expressed in Hz, for example A4, which is the tuning standard for most Western instruments, is measured at 440Hz.

Subtractive synthesis: Made famous by Bob Moog’s synth designs in the 1960-70s

Oscillator: A signal generator. Generally these can output a choice of waveforms

Filter: Removes frequencies from the signal path

Cutoff: The frequency at which a filter will remove audio material

Resonance: Aboost at the cutoff frequency of the filter.

LFO: Low frequency Oscillator. An LFO is a signal generator similar to an oscillator that operates at a much lower frequency, usually below an audible frequency. LFOs are used to modulate other parts of a synth.

Envelope generator: changes over a period of time and can be assigned to various parts of a synth. The most common example of this is an ADSR (attack, sustain, decay, release) envelope.

Patch: A sound designed on a synthesiser. Also refers to the act of assigning one part of a synthesiser to interact with another.