Here are new .mp3s of HT-3000, recorded with KORG AM8000R multi-effects and 4-times multi-tracking. Thanks to AM8000R, movement of HT's SD wave and lo-fi drums are emphasized, and the bass line is made possible. Also I tweaked the dial to add realtime filter movement.
The synthesis engine of CASIO HZ/HT series is called SD - Spectrum Dynamic.
According to CASIO's advertisement and what little sources there are,
it has waveforms that change their harmonics 'temporally and dynamically,'
and it is said to be characterized by its 'clear' sound.
I haven't seen any substantial description about what this really means, ever since they are introduced in 1987.
Recently I got a CASIO HT-3000 without a manual and investigated SD synthesis engine.
I uploaded what I found about SD with some sound examples recorded without external effects.
I think I have found some facts about the SD synthesis, though some mysteries still remain,
especially around its SD oscillator, and I'd like to be informed more.
If you have something to tell about HZ/HT, please let me know.
Overview
CASIO's SD synthesis was first explicitly introduced with HZ-600 in 1987.
It belongs to the lower end of the Z series known by now honored CZ/VZ synths, FZ sampler, RZ drum machine and others.
Soon the all-in-one version HT series (HT-3000 / HT-3500 / HT-700) are released.
They have drum machine and auto-accompaniment function.
CASIO HZ-600 (1987)
The SD synthesis engine is constituted by 1DCO - 1VCF - 1DCA.
So its sound resembles DCO analog synths of that day, with some unique character added by the SD oscillator.
SD synths have two splittable synth parts: Upper Tone and Lower Tone.
Synth parameters for the latter are a bit limited compared to the former.
Follow the link below for details and sound examples.
Update
HT-3000 song #1 (2.5MB)
SD Oscillator
CASIO NZ Manuals in the support page
Deep Synthesis: Home
