SD Oscillator
DCO
Below is the samples of raw - not filtered - waves of HT-3000's DCO.
The upper tone has 32 waves and the lower, 16.
It is notable that the waves respond differently to DCA decay.
So I uploaded two versions of the waves: DCA fully sustained, and shortly decayed.
Wave samples are converted to .mp3 (approx. 16KB each).
32 Waves for Upper Tone
32 Waves for Upper Tone (Short Decay)
16 Waves for Lower Tone
16 Waves for Lower Tone (Short Decay)
What is actually meant by Spectrum Dynamic
My hypothesis is:
The 'DCO' consists of several pulse waves at different octaves.
This is what I call Additive pulse wave synthesis.
It is most notably employed by KORG Poly-800.
Unlike Poly-800, HT seems to be able to control the amp envelope and the pulse-width of each harmonic wave individually.
Hence Spectrum, Dynamic.
Spectrum means additive harmonics, and dynamic means the volume control.
Unfortunately, each spectrum is always a square/pulse wave.
Then, what is meant by its alleged 'characteristically clear sound' ?
It still remains a mystery.
CZ synths are fully digital, and their bit-resolution is much higher.
Most people would think CZ (or most digital synths) sounds clearer than HZ/HT.
Because:
There are too many pulse-sounding waves.
There are many octave-unison-like waves.
The saw wave is stepwise shaped, which is characteristic of additive pulse wave synths.
They generate a saw wave by adding square waves at 4 (or so) different octaves.
Compare the saw waves of HT and CZ below.
Saw wave (HT-3000)
Saw wave (CZ-1)
SD seems to be more advanced than Poly-800, as it can control the amp envelopes of several harmonic waves, as some decay sounds above suggest.
For example: ud23.mp3 (56KB)
Some waves has wierd metallic effect.
This may be created by an internal ring modulator.
For example: u00.mp3 ud08.mp3 ld02.mp3
Noise generator
SD oscillator can generate white noise and 'metallic noise.'
Compare the waves 'u30.mp3' and
'u31.mp3.'
They may be generated by an analog noise generator.
Another possibility is CASIO's Noise Modulation, but it's not certain if HZ/HT uses it.
CASIO CZ is the only digital synth that uses Noise Modulation,
which produces noise with different character by modulating the oscillator's pitch very fast at random.
CZ Noise Modulation (20KB)
Next 
HT series
Deep Synthesis: Home
8. 22. 2002
Modified: 8. 30. 2002