User manual

ManualsBrandsClavia ManualsMusical InstrumentsNord Stage Revision C

Chapter 8 refereNCe: SyNth | 31

sources, or by the Modulation Envelope. This will generate a signal

with continuously varied harmonic content.

If you choose one of the synchronized oscillator modes, the Oscillator

will start over with a new period of the waveform, each time the sync-

oscillator does so. If the Oscillator then has a higher frequency than the

sync-oscillator, it will get a complex waveform that depends both on its

own pitch and on that of the sync-oscillator.

In the Nord Stage 2, oscillator sync is possible with the sawtooth, pulse

and triangle waveforms, each providing a different spectral character.

Frequency Modulation

The basic principle behind frequency modulation (FM) synthesis is to

have one oscillator (the modulator) modulating the frequency of another

(the carrier). The carrier can in turn modulate the frequency of yet

another oscillator, etc. There are several different algorithms in the FM

category ranging from one up to three oscillators (operators) modulat-

ing each other in series, with or without feedback on the ﬁrst operator

in the chain.

FM-Synthesis

FM-Synthesis is a method where the frequency of one oscillator

(referred to as the Carrier) is being modulated by itself using feedback

or, by the frequency of additional oscillators (the Modulators).

The image above shows a 2 Operator FM-Synthesis setup, and the

resulting waveform using a fairly high FM amount setting.

The resulting waveform is far more rich in harmonics than the original

Sine waveform, and drastic changes in tonal character are provided by

altering the amount of modulation.

There are several FM algorithms available; set-ups with various number

of oscillators, feedback and frequency ratio settings between the oscil-

lators.

• Use the Waveform-dial to select the FM-algorithm.

• The Shape parameter is used for setting the amount of modulation

and/or feedback from none to maximum.

There are three main FM algorithms in the Nord Stage 2: one, two

and three oscillator FM with feedback. The feedback is not active in all

algorithms.

The Shape knob controls the FM and feedback amounts. When you

turn the knob, all modulations are increased simultaneously. The

number of harmonics, and their intensity, increase proportionally to the

FM amount. As usual, the Shape parameter can be modulated by the

Modulation Envelope or the LFO, and it can be Morph controlled by

any combination of wheel, aftertouch and pedal.

Each algorithm comes with a number of pre-conﬁgured frequency

ratios. Depending on what kind of sound you want, choose from the

different combinations available and you have many interesting FM

sounds at your disposal. When a new algorithm is selected, the Main

display shows, for a short duration, the algorithm together with infor-

mation on the frequency relations between the operators and whether

feedback is used. The display shows the modulator(s) frequency

relation to the carrier. If an operator uses feedback, it is indicated by a

dot next to the digit. In the chart below all available algorithms together

with the notation used in the display are listed:

FM Algorithms

LED LCD Description (FB = feedback)

CR 1-OP (+FB)

Carrier only, with feedback

1 2-OP 1:1

Carrier + Modulator, same frequency

2 2-OP 2:1

Carrier + Modulator, frequency ratio 2:1

3 2-OP 3:1

Carrier + Modulator, frequency ratio 3:1

4 2-OP 4:1

Carrier + Modulator, frequency ratio 4:1

5 2-OP 5:1

Carrier + Modulator, frequency ratio 5:1

6 2-OP 6:1

Carrier + Modulator, frequency ratio 6:1

7 2-OP 7:1

Carrier + Modulator, frequency ratio 7:1

8 2-OP 8:1

Carrier + Modulator, frequency ratio 8:1

9 2-OP 9:1

Carrier + Modulator, frequency ratio 9:1

1. 2-OP 1:1 (+FB)

Carrier + Mod + FB, same frequency

2. 2-OP 2:1 (+FB)

Carrier + Mod + FB, frequency ratio 2:1

3. 2-OP 3:1 (+FB)

Carrier + Mod + FB, frequency ratio 3:1

4. 2-OP 4:1 (+FB)

Carrier + Mod + FB, frequency ratio 4:1

5. 2-OP 5:1 (+FB)

Carrier + Modulator, frequency ratio 5:1

6. 2-OP 6:1 (+FB)

Carrier + Mod + FB, frequency ratio 6:1

7. 2-OP 7:1 (+FB)

Carrier + Mod + FB, frequency ratio 7:1

8. 2-OP 8:1 (+FB)

Carrier + Mod + FB, frequency ratio 8:1

9. 2-OP 9:1 (+FB)

Carrier + Mod + FB, frequency ratio 9:1

9. 2-OP 9:1 (+FB)

Carrier + Mod + FB, frequency ratio 9:1

11 3-OP 1:1:1

Carrier + Mod + FB, same frequencies

21 3-OP 2:1:1