The CZ series is a family of low-cost phase distortion synthesizers produced by Casio beginning in 1985.

Casio's phase distortion synthesis technique was championed by Casio engineer Mark Fukuda and evolved from the Cosmo Synth System that was developed in collaboration with synthesist-composer Isao Tomita.

[1] To make the CZ synthesizers inexpensive, so they would be affordable to amateur musicians (a much larger market than the professional musician market), Casio used digital synthesis without a filter instead of traditional analog subtractive synthesis with a filter.

For resonant-type wave shapes, the DCW value instead controls the perceived resonant frequency.

In this capacity, it was described by Casio in the CZ-1's manual as being phase distortion synthesis's equivalent of the VCF (voltage-controlled filter) in analogue synthesisers.

[3] 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 modulatory effects of the LFO are controlled by three settings: speed, depth, and delay.

The CZ synthesizers were missing some features common to analog synthesizers: LFO can't modulate DCW, which prevents 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.

It had pegs for a guitar strap so it could be worn,[4] a compartment for 6 D-size batteries,[5] and a headphone output[6] but no internal speaker.

This synthesizer, introduced in 1984,[7] was identical to the CZ-101 in function, but used full size keys and more attractive membrane buttons.

It doubled the memory, was multitimbral, also stored splits and layers as "Operation Memories", and added velocity and aftertouch sensitivity to the keyboard, along with programming parameters to control how velocity and aftertouch pressure would affect the sound.

Page 12 of the CZ-1 operation manual explains the tone output channel settings.

The only features that the CZ-1 lacked in comparison to some other models was the basic sequencer or drum machine sometimes furnished.

Thus the CZ and VZ engines are quite different and not directly compatible, filling different sonic and architectural niches.