Casio CZ synthesizers

The CZ series were a family of low-cost Phase distortion synthesizers produced by Casio mid-1980s. There were eight models of CZ synthesizers released: the CZ-101, CZ-230S, CZ-1000, CZ-2000S, CZ-2600S, CZ-3000, CZ-5000, and the CZ-1. Additionally the home-keyboard model CT-6500 used 48 phase-distortion presets from the CZ line. The CZ series were remarkably flexible synthesizers, and their price made programmable synthesizers affordable enough to be purchased by garage bands. Yamaha soon introduced their own low-cost digital synthesizers, including the DX-21 and DX-100, in light of the success of the CZ series.

Programming the CZ synthesizers

Casio's Phase-Distortion synthesis technique was championed by Casio engineer Mark Fukuda and evolved from the Cosmo Synth System that was custom-developed for legendary synthesist-composer Isao Tomita. Yukihiro Takahashi was also on board during development. [http://www.madtheory.com/CZ%20article/CZ%20article.htm]

To make the CZ synthesizers inexpensive, Casio used digital synthesis without a filter instead of traditional analog subtractive synthesis with a filter. Like many early digital synthesizers, its sound was regarded as "thinner" than the sound of an analog synthesizer. However, the CZ line used phase distortion to somewhat simulate an analog filter, it had in total eight different waveforms: as well as the standard sawtooth, square, and pulse waveforms, it had a special double sine waveform, a half-sine waveform, and three waveforms with simulated filter resonance: resonant sawtooth, triangle, and trapezoidal waveforms. The simulated filter resonance was not considered to sound much like real filter resonance, being a simple waveform at the filter cutoff value instead of a real filter resonating.

Each digital oscillator could have one or two waveforms. Unlike other synthesizers, where having multiple waveforms added the multiple waveforms together, the CZ synthesizers would play one waveform and then play the other waveform in series; this resulted in there being a fundamental added one octave below the pitch of the sound. It was possible to combine two non-resonant waveforms together, and to combine a resonant waveform with a non-resonant waveform, but it was not possible to combine two resonant waveforms.

The CZ-101 and CZ-1000 had only eight digital oscillators. For patches using one oscillator per voice, this allowed 8-note polyphony, but if two oscillators per voice were used, this restricted polyphony to four voices. The CZ-3000, CZ-5000, and CZ-1 had sixteen digital oscillators, making them sixteen- or eight-voice synthesizers. Each of the oscillators in a two-oscillator patch could be independently programmed.

The envelope generators in the CZ synthesizers were far more flexible than a traditional four-stage ADSR envelope; they were eight stage envelope generators where each stage had a rate and level value. The rate value determined how fast the envelope would move; the level value would determine what pitch/filter cutoff/volume the envelope would have. There was a single sustain stage, and an end stage. The synthesizers had but a single LFO, which could only moduate the pitch of all voices in a given patch. The LFO had triangle, square, up ramp sawtooth, and down ramp sawtooth waveforms. The LFO had only three settings: speed, depth, and delay. The pitch of a voice could also be modulated by a dedicated eight-stage envelope; the envelope generator, alas, could only increase the pitch of a sound.

Each DCW (what Casio called the phase distortion part of the sound which determined how many harmonics a given sound had) was also modulated by a dedicated 8-stage envelope generator.The DCA (which determined how loud a given oscillator was at a given moment) was also modulated by another dedicated 8-stage envelope generator. The DCW and DCA also had a "key follow" feature; which determined how much higher notes affected a sound, making the DCW have a more dull sound with less harmonics with higher notes, and making the DCA envelope faster for higher notes.

It was possible to modulate the two voices in a two-voice patch in two different ways. Ring modulation had the output of one of the oscillators affect the volume of the other oscillator, resulting in a controlled distortion. Noise modulation caused the second voice in a two-voice patch to sound like digital noise, roughly simulating the effect of an analog synthesizer's noise source.

The CZ synthesizers also had the ability to stack up two different sounds via the "tone mix" feature resulting in a functionally monophonic synthesizer; this was Casio's version of the "unison" feature other polyphonic synthesizers had. Each part in a two-patch stack could be a different patch, allowing great flexibility in stacked sounds. It was not possible, alas, to detune the two patches in a tone mix stack; this could be somewhat worked around, however, by giving each of the two patches a different vibrato rate.

The CZ synthesizers did not have some features that analog synthesizers had: it was not possible to modulate the DCW with an LFO; it was not possible to have pulse width modulation; the simulated resonance was an either-or proposition; with the exception of a resonant form, it did not have a triangle wave.

Individual models

CZ-101

The CZ-101 was the first and best-selling synthesizer in this line. Approximately 68,500 were manufactured. Coming out in 1984, it was one of the first (if not the first) fully programmable polyphonic synthesizers that was available for under $500. In order to keep the price low, several compromises were made. The CZ-101 only had 49 keys (4 octaves from C to C) instead of the 61 keys most synthesizers had. Instead of full sized keys, the CZ-101 used miniature keys.

CZ-230S

The CZ-230S was released in 1986. Despite the CZ-230Ss model numbering, it was not really a programmable synthesizer; the specifications of this model more closely resembled that of one of Casio's home keyboard models. It used the synthesizer technology of the CZ-101 in a 100 tone preset sound bank, had a mini keyboard of 49 keys, incorporated the RZ1 drum computer technology and had a built-in speaker. Only four of the sounds in the sound bank could be programmed by linking the synthesizer to a computer via its MIDI port.

CZ-1000

The CZ-1000 was the second fully programmable phase distortion synthesizer that Casio introduced. This synthesizer, introduced in 1985, was identical to the CZ-101 in function, but used full size keys and more attractive membrane buttons. It was also somewhat larger than the CZ-101. Like the CZ-101, this synthesizer had 49 keys.

CZ-3000

The CZ-3000 synthesizer used the same phase distortion engine as the CZ-101 and the CZ-1000, but added the following features:

* The synthesizer had eight voices instead of four voices (16 oscillators instead of eight)
* It was possible to split the keyboard (in other words, have some keys play one sound while other keys played another sound).
* The synthesizer had 61 keys, not 49 keys
* There was a built-in chorus effect
* Instead of having just a pitch bend wheel, the CZ-3000 had both a pitch bend wheel and a modulation wheel.

CZ-2000S

The CZ-2000S synthesizer was a rare model that was not sold in North America. It was identical to the CZ-3000 except that it also had built-in speakers.

CZ-2600S

The CZ-2600S synthesizer was a rare model that was not sold in North America. It was identical to the CZ-2000S except that it was a stereo model.

CZ-5000

The CZ-5000 synthesizer was almost identical to the CZ-3000, but had more memory for patches, and a built in sequencer. In most other regards, it was virtually identical to the other CZ series synthesizers.

CZ-1

The CZ-1 synthesizer competes with the CZ-5000 for the title of most advanced in the CZ series. The CZ-1 had all the features of the CZ-5000 except the sequencer. However, the CZ-1 added velocity and aftertouch sensitivity to the keyboard, along with programming parameters to control how velocity and aftertouch pressure would affect the sound. In this respect the CZ-1 is the most advanced CZ synthesizer. The CZ-1 also featured a backlit display - a small but nice improvement over the rest of the series.

See also

* Phase distortion synthesis
* Casio
* Synthesizer
* Musical instrument
* Musical keyboard
* Casio SD Synthesizers
* Casio MT-40

External links

* [http://hem.passagen.se/tkolb/art/synth/cz1000_e.htm Casio CZ-1000 Details]
* [http://www.obsolete.com/120_years/machines/casio/ Casio Synthesizers history from 1982 to 1992]
* [http://www.retrosound.de/cz-1.html RetroSound Casio CZ-1 Page]
* [http://www.mcrow.net/White%20Crow.htm Virtual Phase Distortion Synth]
* [http://www.cosmosynthesizer.de cosmosynthesizer.de - Casios CZ models, history and demos incl. the hidden Waveforms]
* [http://www.cosmods.de cosmods.de - details for the Casio RZ-1 Rhythm Composer with ROM and RAM update]