In 1987, Casio discharged another Spectrum Dynamic combination available. On a basic level, the SD synthesizers are computerized simple half breeds with eight voices of polyphony.

The first of SD instruments was a "professionally" looking bitimbral synthesizer HZ-600, which was trailed by HT-3000, a home console like instrument with programmable programmed backup, 61 standard-size keys and implicit amplifiers, HT-700 with the same elements like HT-3000 yet with 49 little keys, and MT-600, a preset variant of HT-700.

The Spectrum Dynamic (SD) means that some of 32 digitally produced waves (for Upper voice) are advancing in the time. In the wave memory, there are additionally established sawtooth, square and heartbeat waves, and also background noise consolidated waves.

The instrument permits to conform pitch-twist range (2, 3, and 5 semitones), transposition (+6/ - 5 semitones), to deactivate the Auto Power Off capacity, and to control the basic MIDI usage: The essential channel is flexible somewhere around 1 and 15 (for Upper tone), the Lower tone dependably utilizes the accompanying higher channel. HZ/HT instruments perceive note on/off, move of wheels (the Modulation must be exchanged on) and program change summons.

Programming of the instrument is finished by two switches (Parameter and Value) and on enormous Alpha-Dial like wheel. Luckily, all parameters are imprinted on the consoles front board which makes this programming strategy worthy.

The console without speed and weight affectability looks and feels precisely like the console of CZ-3000/5000. It can be splited in one of three split focuses, yet by means of MIDI, the Lower and Upper tones can be controlled autonomously, layered on entire console range, or splited anyplace.