A Historical Look Inside Analog and Digital Sound Synthesis

In the day and age of EDM’s skyrocketed popularity, new producers are popping up daily. I am constantly hearing about new acts and hearing increasingly talented ideas expressed musically. I remember when I started my project Aplsoz, I had zero clue of how to approach making some of the wild and wonky sounds that had blown my mind in the live music environment. Acts like ill Gates, Bassnectar & Freq Nasty opened a portal for me sonically that I couldn’t ignore. I became hooked on sonics.

Eventually I found out that electronic sounds can be generated in a multitude of ways. The most common form today is digital synthesis, using software on a computer or even physical digital synthesizers, such as a Yamaha keyboard. Another vastly interesting and hands-on approach is analog synthesis. Before we go deep into each subject, let’s discuss what analogue and digital synthesis really are.

First we’ll touch on digital synths and synthesis.

Digital synths use what’s called digital signal processing or (DSP) to execute a vast array of signal processing operations. These signals are a sequence of numbers that represent samples of a continuous variable in a domain i.e. (time, space, frequency, etc.). The signals are processed and read into analog signal that can generate tones. Using an algorithm created by John Chowning, engineers were able to evolve early work on FM synthesis or Frequency Modulation to add improvements to commercial synthesis and generate the first commercial digital synthesizer. This application allows for many advantages over analog processing such as “key scaling,” which avoided the distortion that frequently occurred in analog systems. The first digital synthesizer was built in 1974 and they have continued to evolve to their internal counterpart, the VST or Virtual Studio Technology.

From here we can see that digital signal processing is responsible for the first digital synthesis using computers to generate sound and using algorithms for frequency modulation synthesis. VST’s were created by Karl Steinberg in 1996 when he released the newest version of his brainchild, Cubase. Cubase 3.02 was the exact version and originally these VST’s only effected external input audio rather than being actual synths themselves. In 1999 Steinberg updated his VST design to include the ability for plug-ins to receive MIDI data and changed the game. The VST Neon soon followed and was released with Cubase 3.7, which was a 16-voice, 2-Oscillator virtual analog synth. Game on for all the closet producers wanting to organize sounds via computer affordably. Finally, you could just enter notes in and get a variety of sounds in return, rather than just one instrument.

If digital synthesis involves digital signal processing or the generation and processing of electronic signals to create sound, then how do analog instruments create sound? When I first started learning about analog sound design and the hardware synths that generate it, I was kind of mind blown. The idea of creating sound with an analog synth was actually more simple than digital sound design in that you get to physically alter the sound with your hands. The pathway of current that ultimately is used by a machine to generate sound was physically observable with knobs you could twist and cables you could use to send the signal to other “places,” rather than just clicking and dragging with a computer mouse.

The different “places” I am referring to are physical pieces of hardware that modify the signal of AC current that you can manipulate with patches, cables or different various knobs and switches known as Modifiers. Some frequently used modifiers that can be seen visually within VST digital counter parts include Oscillators, LFO’s, Filters, Voltage Controlled Amplifier and Envelope. Here are some brief definitions of each:

Oscillator: A Modifier that generates a fundamental harmonic in one of a few different but simple waveforms i.e. (sawtooth, sine, square & triangle) as well as other complimentary frequencies.

LFO: A Modifier that allows the oscillator to be modified according to a simple, low-frequency wave shape; most commonly adjusting amplitude (depth) or its frequency (speed).

Filter: A Modifier that filters out certain frequencies of the output sound. Some common filter types are High pass, Low pass, Notch & Band pass. High pass filters let high frequencies past. Low pass filters let the low frequencies past. A Notch filter creates a “notch” in the center of the audio’s EQ spectrum, leaving lows and highs but removing a section in the middle. Band pass filters basically do the opposite of a Notch filter and leave the center frequencies and remove lows and highs.

VCA (Voltage Controlled Amplifier) and Envelope:

A Modifier that allows volume control in several ways. The Envelope creates various points in the sounds amplitude to shape it with attack, decay, sustain and release controls, otherwise known as ADSR. Attack sets the amount of time it takes for the sound to be heard from complete silence. Decay is the amount of time the sound takes to lower from full amplitude to the sustain level. Sustain is the sound level when a key is pressed down and held. Release is the amount of time it takes for the note to fade to silence from the sustain level.

The earliest Analog synths were made in the 1920’s & 1930’s but arguably the hay day was in the 1970’s and 1980’s. Today there has been a massive resurgence of Analog synth use, especially in EDM music. In my opinion the underground bass music scene has lead the race of experimental Analog sound design and set the bar in sound development. Now that instruments are becoming more affordable and information more readily accessible, we are hearing the increasing use of these beautiful, beastly machines. Analog synthesis has a certain warmth to the tone that is fully representative of a high quality sound. The rich full size isn’t re-creatable and that is due to the tonal character of the sounds derived from operating in the world of electrical current, rather than a mathematical program.

I am deeply infatuated with the idea of Analog synthesis as well as Digital synthesis and I hope after reading this you can take a couple things with you and make some fun sounds yourself. If you are a new producer or you’ve been doing it for years, I hope that I was able to provide an interesting peak into these layers of sound synthesis. Every day we are learning more and more about new ways to create sounds and share them with each other and I think that is an amazing thing to be a part of. Good luck on your sonic adventures and happy learning!

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