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Analog Synthesis

The fundamentals of analog synthesis are handy to know, even if you never set foot near an analog synthesizer.

For one thing, many digital synthesizers and virtual sound sources use the same basic structure. Knowing how these elements interact is an extremely helpful basis for sound design and manipulation — or even for just shopping for a new electronic instrument, to know something about what you will be getting!

  • The basic sound source is an ‘oscillator’. This can be an harmonically – rich tonal waveform like a saw wave, a square wave, or a sine wave, or it can be a ‘noise’ waveform that generates activity across many frequencies (often useful for percussive sounds, or for adding non – note ‘color’ to a sound.
  • The output of the oscillator is then acted upon by a series of modulators, filters, and amplifiers. The simplest arrangement is the classic Oscillator -> Filter -> Amplifier circuit, used on countless synthesizers past and present. The output of the oscillator has some or all of its frequencies ‘filtered’ (removed or attenuated) and the output of the filter is then amplified by the final stage… which, on analog synths especially, is necessary to make the purely electronic signal into something that can be heard.

There’s far too little space here to go into the many types of filters and modulators, but by far the most common is a lowpass filter with a cutoff and resonance variable. The cutoff tells the filter where to start filtering, so to speak; moving the cutoff in real time will allow you to make the sound ‘brighter’ and ‘darker’ by removing more or less of the lower frequencies.

The resonance control allows you to boost the harmonics at the point at which the filter begins, causing the overall filter effect to take on a more obvious or subtle character (at extreme ends, the filter itself generates sound — what is known as ‘self – oscillation’, a highly sought – after effect in certain synth circles!).

What this means to you is that you will have a very nice sound. When it comes right down to it, isn’t that what we are all working towards… I mean I know that those of us who have chosen this path are all travelling it together. We want to march to the beat not just of a drum but to that of an entire orchestra. even better yet, is when we have that orchestra at the touch of a button. That is when the world of music really starts to take shape. It’s an amazing time we live in and I for one, consider myself lucky to be a part of it. You should likely do the exact same thing too.