Korg PS Polyphonic Synthesizer PS-3100
Owners Manual

2. THE SYNTHESIS OF SOUNDS ^

2-1 Thinking About Sound Synthesis

Let's explore the creation of sounds by means of the PS-3100 synthesizer.

With most synthesizers the user can control at will volume, pitch, tone color (timbre) and their variations in time. However, the one factor that sets a limit on the number of sounds that can be created is the number of VCO's (voltage controlled oscillators) that the synthesizer employs.

Equipping the synthesizer with a number of VCO's is not only useful for adding to the depth of the sound but is also effective for creating a feeling of harmony. However, the fact is that so-called polyphonic synthesizers have relied on the employment of a number of VCO's without being equipped to produce sounds that fully qualify as polyphonic.

As you have understood from the explanation so far, every capability of the synthesizer is available when even one key is pressed on the PS-3100.

In this respect it is a truly unique keyboard instrument. The PS-3100 has true polyphonic synthesis capability. In other words it may be played just like other keyboard instruments thus satisfying a need that monophonic synthesizers could not, while at the same time making playing itself a much easier matter. In this sense, the PS-3100 is an epoch making instrument that greatly broadens musical possibilities.

bullet Understanding the basic nature of sound.

In order to create a particular sound you must first separate sound Into Its elements of volume, pitch, tone color, and time changes and then use each of these elements to put together the sound you want. By the same token, if you don't have the ability to take apart and analyze the sound you are trying to produce you will not be able to recreate it.

In order to develop this kind of ability you can try analyzing the great variety of sounds you hear around you every day while at the same time experimenting with the controls on the synthesizer panel until you are familiar with exactly the type of effect each knob controls.

bullet Let's take the time signal recorded on the demonstration tape [included with the instrument] as an example and try to analyze it and then recreate it. (This time signal is used by Japanese radio stations.)

The time signal is made up of a combination of two types of different tones, three short ones and one long one. One very obvious difference between the two sounds is their envelope, another is their pitch. The final long tone fades away over a long period of time while the three initial short tones end very abruptly. You may be able to tell from experience that the difference in pitch between the two sounds is a matter of one octave. What about a difference in tone color or timbre? Is there any change or are the sounds basically the same? One thing that can be said about these tones Is that they have a rounded quality. Now let's try and recreate these sounds.

Illustration of a time signal

Figure 32 - Time Signal


bullet a "rounded" sound:

bullet The time parameters of the first short tone:

bullet The time parameters of the final long tone:

bullet Timing:

While listening to the sound thus produced you can make corrections for small differences in nuance. By creating slight changes in tone color and other elements of the sound you can begin to understand in a practical way the relationship between the controls and the sound produced by adjusting them. This will obviously be of value when you move on to make more complex sounds and music. In any case it should be clear how important it is to develop this new way of thinking about sounds and their creation.

Creating sounds with the PS-3100:

The sound of chimes is a sound rich in harmonic relationships. With an ordinary monophonic synthesizer such a sound is produced by means of a ring modulator which produces irregular harmonics with a view towards the required number of frequencies. Although this method may be employed with the PS-3100, there is a better way of going about it. Since all the keys of the PS-3100 will produce sound at the same time, you may view the entire keyboard as a row of harmonics and by playing a number of keys at will you can create the type of harmonic structure you want. (This is not limited to odd and even harmonics; by changing the pitch of the appropriate key or keys you can freely create a variety of irregular harmonics also.)

As you can see, the possibilities of the PS-3100 are virtually unlimited. Taking the above example, you can easily create one sound that is extremely full and rich by using the entire keyboard. But in order to really challenge all the possibilities latent in this instrument, it is necessary to clearly understand the function of each and every control available and then discover how to use these controls in combination to their full potential.

2-1 Thinking About Sound Synthesis
2 - 2 Creating Sounds Using The Built-In Patch
2 - 3 The Basic Process Of Sound Synthesis
2 - 4 Understanding The Patch And Its Use



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