Analog Synthesizers: The basics

Analog Synthesizer are instruments that manipulate concrete voltage signals into sculpted sound waves with different forms and characters. The final result of the synthsised sound depends on the chosen filters and envelope generators parameters. Unlike their digital processedors, their sound is richer on overtones, warmer and more pleasant. Here we explained the several types and mechanism of analog synthesisers.

How Do synthesisers work?

1. Generators or oscillators (VCO)

It starts from a voltage that can be shaped into different waveforms.

▪︎ Sine: a simple pure tone without any harmonics.

▪︎ Square: it has a reedy texture.

▪︎ Sawtooth: the sound is bright and rich in harmonics.

▪︎ Triangle: It has a smoother sound than the square waveform.

1. Frequency Modulation (FM)

This is where different filters are used to alter the sound spectrum.

▪︎ Cut Off Frequency: it's used to select the Low-Pass and the High-Pass filters starting point.

▪︎ Low-Pass filters (LPF): The allow the frequencies below the Cut Off Frequency to pass through.

▪︎ High-pass filters (HPF): They allow the frequencies above the Cut Off Frequency to pass through.

3. Envelope generators and dynamics

The envelope generators define the dynamics of the sound. In analog synthesisers, it's possible to modify their four elements which are:

▪︎ Attack: The time that the sound requires to reach its full volume at the beginning of the note.

▪︎ Decay: The time that the sound takes to fall from the attack level to the sustain level.

▪︎ Sustain: The maintained level of the played sound.

▪︎ Release: The time that the sound takes to completely fade away after the Release of the note.

Which are the different types of synthesisers?II

1. Modular Synthesizers

· Key features: the ability to generate many frequencies simultaneously and connect them to other modules usingpatch cables and control voltage generators to shape envolopes and modulate the wave forms.

Adding effect modules in any particular order. Crossmodulate different Oscilators etc. The options are almost endless.

· GUI quality and usability: the GUI permits precision and accuracy.

· Main strength: Many sound modulation tools and great control over sound.

· Why: great versatility, if used with care, the synthesisers can serve a wide variety of musical styles and audio material, providing a rich and complex synthesised sound.

· Down Sides: Expensive to start with. Deep knowledge of singal flow and Synthesis is needet. Very Time Consuming, Highly Addictive! ;)

2. Polyphonic Synthesizers

· Key features: Portable instrument that allows musicians to create rich and complex sound everywhere.

· GUI quality and usability: the GUI is easy to use, offering a piano keyboard to play the different chords.

· Main strength: It's used as a musical instrument with a real-time modifiable timbre.

· Why: It can be used in different music genres and it serves for sound design as well.

· Down Sides: Mostly limited to a fixed singal flow. With exceptions like the Arturia Matrix Brute or the Moog One where you can edit and modify the routing matrix. Much more expesive then Digital based Poly Synth or Plugins

3. Monophonic Synthesisers

· Key features: Small and portable.

· GUI quality and usability: Very precise and useful to modulate and modify a monodic sound.

· Main strength: Affordable and easier to use for specific tasks.

· Why: It can be used to modify the timbre of monodic instruments and percussions.

· Down Sides: You need to duplicate it in the case you need a polyphonic sound.

4. Semi-modular Synthesisers

· Key features: It can be connected to other synthesizers to treat previously modulated sounds.

· GUI quality and usability: The base routing is set, no cable conections are needed, so it´s quicker to use then a fully modular synth.

· Main strengths: Modulation sources can be addet from olther synth and modules, the singal flow can be altered.

· Why: Very useful to treat sounds coming from other instruments. Advantages of a fully monophonic synth comboned with the flexibility of a modular system.

· Down Sides: Not every parameter is freely accesable like on most modular synth.

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Useful Links:

https://www.musicradar.com/news/what-is-modular-synthesis

https://www.sweetwater.com/insync/best-monosynths/

https://magneticmag.com/2023/05/the-best-semi-modular-synths/

https://reverb.com/guide/the-best-analog-polysynths

https://blog.native-instruments.com/music-synthesis-101/

https://www.moogmusic.com/synthesizers