Waveform
Internal format for waveform
Officially, CZ has 8 basic waveforms, and two of them can be combined to make a new wave.
As particular set of combination is not viable, there are 33 waveforms in total.
1: Sawtooth
2: Square
3: Pulse
4: Double-Sine
5: Saw-Pulse
6: Resonance I (Sawtooth)
7: Resonance II (Triangle)
8: Resonance III (Trapezoid)
Internally - at SysEx level, its waveform is represented as below.
First wave: 0-7
Second wave: 0-7
Window Function: 0-5
The actual basic waveforms
There are 8 basic waveforms, but they are different from official waveforms above.
Specifically, there are no 'Resonant waves' (#6-8) as such.
Below is the list of the actual basic waveforms.
The wave number is modified to match the official number.
'*' shows the previously unknown waves, which are named by me.
1: Sawtooth
2: Square
3: Pulse
-: Null *
4: Double-Sine
5: Saw-Pulse
6: Sine Sync *
7: Narrow Pulse *
(mp3 conversion may have damaged the higher frequencies to some extent.)
'Null' wave does not produce audible sound itself, and only a small click can be heard.
I suppose that it is similar to YAMAHA SY77/SY99's 'Fixed Frequency at zero Hertz' and Roland Super JV's 'DC Wave.'
Its inaudible power can be heard when some modulations are involved.
Ring Modulation with Null wave (produces slight click)
'Sine Sync' is the basis of CZ's 'resonant waves.'
Resonated higher harmonics is generated by Oscillator Sync with two sine waves.
This process is done in a single DCO, and I call it 'Sine Sync' ('Cosine' might be better for CASIO crews).
I emulated CZ's Sine Sync by Ensoniq ESQ-M's real Oscillator Sync.
CZ's Sine Sync
ESQ-M's Sine Sync
Sync generates its own noisy harmonics.
CASIO uses what they call 'Window Function' (Additional Ring Modulation - See the next section) to eliminate the sync noise.
Above is the raw form of the Sine Sync wave, without the use of window function.
Sine Sync can be used to imitate 'Oscillator Sync' of analog synths,
especially when in combination with 'Octave Modulation' described below.
It's a rare ability among digital synths, except KORG WAVESTATION and Roland JD-990.
'Narrow Pulse' is named as its waveform is displayed as a sharp pulse.
Even when DCW level is low, this wave still retains its pulse form.
Narrow Pulse with DCW decayed to Zero
Octave Modulation
CZ can combine two waveforms in a single DCO.
That is, a DCO can alternatively playback two different waveforms.
Unlike WAVESTATION, CZ alternates the waves at each single wave cycle,
audio range modulation produces another new waveform.
It is said that CASIO called it 'Octave Modulation.'
(Its detail is not clear.
I suppose that the name comes from the fact that the resulting sound is often lowered by one octave, as the wave cycle is doubled.
When different waves are alternatively played, something like a loop noise often emerges.
Such noise can often be heard in PCM-based wavetable synths - most uniquely in Ensoniq VFX;
see Ensoniq SQ-R page for related information.
It is said that CASIO employed some smoothing function in Octave Modulation.)
While officially the combination of the waves is limited, internally, any two waves can be combined.
Even 'Null' wave can take effect when combined with other waves.
Using 'Sine Sync' wave with Octave Modulation, differently colored 'Oscillator Sync' sounds can be obtained.
Sawtooth + Null
Sawtooth + Narrow Pulse
Next 
CZ series
Deep Synthesis: Home
8.30.2002
modified: 8.25. 2004