Casio VZ-8M Operation Manual

Also see for VZ-8M: Guide Operation manual

Casio VZ-8M Operation Manual Manual pdf 13 page image

Theory: iPD Modular Sound SystemlI;!'1At the heart of the VZ's amazing sound synthesis capabilities is an all-new "iPD" (interactive Phase Distortion) sound source. In order to getthe most out of your unit, it is vitally important that you understand atleast the basic theory behind this new sound source.MODULESThe iPD sound source system actually consists of 8 independent modules(Ml to M8).Each module contains a DCO and a DCA, and is capable of generatingindependent waveforms. (©) If you're familiar with analog synthesis, youcan think of the modules as oscillators with controls. In the iPD system,the wave generated by any module can be used in either of two ways;1 — to produce audible sounds2 — to modify waves generated by other modulesLINESGenerally speaking, the 8 sound source modules work in associated pairsthat are called "Internal Lines," or simply "lines." There are 4 internallines — A, B, C and D, as shown to the right. (®)The waveforms generated by both modules in any line can be used togetherin three different ways. The waveforms can be mixed, or one of the waveforms can be used to modulate the other for RING modulation or PHASE,as diagrammed at the right. ((§))To show how the modules in each line are interrelated, let's analyze therelationship between the two modules which make up LINE A.LINE A consists of two different modules — Ml and M2. While thesemodules are entirely independent and generate totally independent waveforms, they can be utilized together in any of three different output formats — MIX (mixed output), RING (ring modulation) and PHASE(phase).MIXED WAVEFORM OUTPUTWhen MIX is selected, the waveforms generated by Ml and M2 are output together, according to the formula given below. (©)MIX: Ml + M2This may look a bit complex at first, but it's really not. It may be easiestto think of Ml and M2 as individual oscillators (which they are). In theMIX format, both of these oscillators sound together.RING MODULATIONThese same two waveforms can also be output using RING MODULATION, which is created according to the formula shown below. (®)RING MOD: M2 + M2 x MlYou've probably heard ring modulation — even if you don't recognizethe term. Typically, it creates a "clangorous" or metallic sound and isoften used in synthesizing gongs, bells and other ringing percussive sounds.■»- A