B.6 HARMONICS

The default output from an operator is a sine wave, but you can use the HARM parameter to add upper partials to some of the operators’ sine waves to create more harmonically rich waveforms. The HARM parameter is bipolar. Negative parameter values change the harmonics of operator C, while positive parameter values change the harmonics of operators A and B1.

Harm -

Harm +

When changing harmonics, intermediate values interpolates between the current and the next harmonic. This interpolation works much like in wavetable synthesis, sweeping between the harmonics, smoothly transitioning from one timbre to another. For more information, please see “A.2.1 FM TONE” on page 89. The harmonic series for the operators looks like this:

Saw (All partials)

Saw reduction

Odd/Even Mix

Square (Odd partials)

Square reduction Bell The Digitone II uses a form of additive synthesis to create the harmonic series for the HARM parameter. Additive synthesis is one of the oldest forms of electronic sound generation. It is a quite simple form of synthesis but still very powerful. The basic principle is to add multiple sine waves together to form complex timbres. Each sine wave is called a partial. By attenuating each partial, the timbre changes its harmonic content, resulting in different waveforms.

The first partial is always kept

at full volume, which keeps the

base octave intact.

Adding every partial in series

will replicate a sawtooth. Note

how the volume decreases for

each partial, creating a natural

falloff.

Adding every odd partial in

series will approximate a

square wave.

The additive method can be

used to make many different

timbres. This combination of

partials, for example, sounds

close to a bell tone.

B.7 SYN PAGE 1 PARAMETERS OVERVIEW

Here is a graphical overview of what part of the FM engine the parameters on the SYN1 pages affects. The affected part of the FM engine is highlighted with grey. For more information, please see “A.2.1 FM TONE” on page 89.

Detune Ratio A

Ratio B

Ratio C

Harm -

Harm +

Feedback Mix