From: dm@everexn.com (Dan McMullen) Subject: Re: VZ-10M (things i wish i'd known before buying) Date: 14 Oct 90 18:10:12 GMT i also joined the pack that picked up a vz10m from sam ash lately. bought 2 actually, one for a friend who could use the voices. i do like it, so in spite of the comments below, i'd recommend it at the current price. there are a few things however that i'd like to have known ahead of time. so for the rest of you, here are my beefs (so far: i've only had it a few days now. i'm a terribly critical person when it comes to music gear i'm afraid.) 1. although some of the postings make it seem that the vz10 could be an enhances cz class machine, it is actually a completely different beast. some of the internal mechanisms for generating the sounds may be similar, but any hope of tapping the vast library of pd cz-? patches is in vain. i was most interested in the vz because i've always liked the guitar and flute sounds from the cz series, but no direct port of the particular sounds i like is possible. 2. the vz10m is no nearly as quiet as the cz machines. one of the cz's best features is that it is DEAD quiet. no such luck on the vz. patches that don't have a loud sustaining portion reveal a distinct fuzz or hiss as they decay, until some sort of noise gate or internal oscillator on/off mechanism kicks in. this is not too terribly bad, and in most music this noise would be masked by other instruments, but for sparse arrangements featuring just a vz voice it is noticable. 3. the manual is (IMHO) awful! a perfect example of describing in painful detail how to program a synth, with very little info on whats going on and why you might want to twiddle this or that parameter. especially considering that knowledge of the cz series doesn't help hardly any, this hurts. i have ordered an applications guide to the vz series that i hope will do better, but as it stands i feel completely on my own in figuring out how to achieve any particular sound i might be shooting for. (not that this is necessarally bad mind you. i might come up with a unique technique or two by not having been told how to do it 'right'.) (the application guide is by Steve DeFuria, keyboard mag columnist, writing with a (japanese?) fellow whose name i can't remember. don't have the title at hand either, but it's something like "power play vz1/vz10m"?) anyway, this has gone on too long. i'm sure i'll find more things to gripe about, & i'll post if there's intrest, BUT i do like this box (REALLY!). any interest in a usenet user group/mailing list. seeing as how there's no real pd soundbase out there (that i know of) it could be very beneficial. -- dan mcmullen, everex systems, inc., sebastopol, ca. (707) 823-0733 dm@everexn.com ...!{well!fico2,pacbell!mslbrb}!everexn!dm From: dalgic@Neon.Stanford.EDU (Ismail Dalgic) Subject: Re: Casio VZ1 - help Date: 13 Feb 91 03:50:52 GMT I bought my VZ-1 last month for 429 US dollars, and I'm smiling ever since. I know that Casio has this bad reputation of making only toy keyboards, but this is really a pretty good intro level synth, definitely worth the money. You are right, it is a 16-voice polyphonic synth with a 5 octave, velocity and aftertouch sensitive keyboard. It is also 8-way multitimbral with static assignment of polyphony on each channel. You can split/layer 4 voices. There are 64 ROM preset patches, and 64 ROM combi areas where performance parameters such as keyboard layers/splits, portamento values etc are stored. Also, you can store 64 patches and 64 combis in RAM. In addition, it comes with a 128 voice/128 combi ROM card. In my opinion, some of the presets are really good, and some just plain useless, with perhaps a half/half split between the two (your mileage may vary :-). Another good thing is that in addition to the pitch bend wheel, there are two user definable modulation wheels. Also, there are inputs for a foot modulator, foot volume pedal and sustain pedal. MIDI implementation is fairly good, although there are some things missing, like there is no local on/off and no program change mapping. This makes it a little inconvenient to use it as your master keyboard. As far as its sound architecture goes, there are 8 "modules" per voice. Each module consists of an oscillator with 8 possible waveforms, an 8 stage envelope generator for the amplitude, and an LFO that can modulate the EG. Also there is a pitch EG with its corresponding LFO, that can affect all of the 8 modules. The modules are organized in pairs, where the oscillators in each pair can phase modulate or ring modulate each other, or are simply added. Also, the output of a pair can phase modulate the next pair. So it can be in a sense like an 8-operator FM synth with some limitations (like no feedback), or an additive synth with 8 partials, among other things. I think it is a pretty flexible architecture. Also editing from the front panel is quite easy and intuitive. The largest complaint I have about it is the lack of public domain support. There are no PD patches or editors/librarians as far as I know (I was particularly looking for IBM stuff, so I don't know about the ST). Right now I'm working on writing a Glib based ed/lib for it, but given my PhD workload, it will take a few months for me to finish it. --Ismail Dalgic dalgic@cs.stanford.edu From: defrain@ei.ecn.purdue.edu (master guru) Subject: Re: VZ-10m Synth Programming Date: 18 Oct 91 16:03:46 GMT The VZ-10M and the DX-7 operate in the same general fashion. The VZ is, however, considerably more sensitive to changes in its program modifications. Understanding FM synthesis would help (at least it helps me out at times) but understanding iPD will help even more. >What is the actual mathematical description of what is going on in iPD >synthesis? In general we have something like y[t] = f[t + a(t)] where f[t] is some modulator output function and a(t) an external phase distorter. f[t] might be a sine wave of 440Hz or a square wave or whatever. a[t] can be these functions as well -- it`s effect, however, does nothing to the amplitde of y(t) (well, actally it can, but let`s not do this to ourselves today). a(t), essentially, "shifts", or modulates, the freqencies of f[t]. In one case, if a(t) is a linear function of time then it`s effect would be to pitch shift f[t] by an amont directly proportional to its slope. Now, say a(t) is a sine function whose freqency is close to that of f[t] then we will, in effect, change the modlator output waveform dramatically -- althogh perhaps maintaining the same fundamental. One last case, say a(t) is many times higer frequency then f[t] and of modest amplitude then we will enhance the brightness of f[t]. The list of possibilities goes on but we all get the point by now. Following this line of thought -- iPD synthesis is equivalent to FM synthesis -- the only difference being it`s mathematical representation. (in FM, strictly speaking, y(t) = f[t] * a(t) for example). Of course, our f[t] could be some f`[t] from another modulator and our a(t) could be as well. Also, we have envelopes to shape our amplitudes and envelopes to shape our frequencies and LFO`s just for kicks. Hmmm, this is getting interesting isn`t it (tremelo, glissando, portamento, vibrato,....). How does one keep track of all this. I don`t know. First trick is to start out with nothing and build off the 7/8 modulator pair and work towards the 1/2 pair --> this of course leaves you with phase inputs from the "lower" modules (these should have been numbered the other way). Next trick is to fix your amplitude envelopes to shape the effects of each individual modulator (after deciding how to program the modulator structure so you know which modulator is going to do what to the sound). Select your waveforms next to give you the effect you`re listening for not forgetting about all the ways yo can pitch shift these with another set of envelopes. During this whole process be sure to keep tabs on the modulator output levels else the "intended" sound could get lost in the "distortion" part if the iPD. Regarding subsequent "combination" of sounds/patches --- developing a patch for a specific combination is all too complicated for myself at this time. Just mix and match. But if you`re so patient and dilligent some nice effects can be had with this foresight. Anyways, this is how I TRY to go about things --- I rarely suuceed as much. ............................................................................. Paul D. DeFrain : "Physical concepts are free creations of : Purdue University, : the human mind, and are not, however it : Dept. of Electrical Engineering : may seem, uniquely determined by the ex- : defrain@ecn.purdue.edu : ternal world." --- A. Einstein : (317)49-43556 (am), 497-9903 : ......................................... : From: glennd@athena.arc.nasa.gov (Glenn Deardorff - GDP) Subject: Re: VZ Synthesis Method Date: 10 Dec 91 22:36:48 GMT Unfortunately, the manual for the VZ doesn't talk at all about what Phase Distortion actually is. Under their "theory" section, they merely describe the voice architecture. The CZ-101 manual actually describes the PD sound synthesis technique to some extent. I won't attempt to recreate their diagrams with cutesy little ASCII characters, but instead will use more characters describing it. They talk about what happens to the carrier wave in terms of its "phase angle", because the phase of the wave (in the example's case, a cosine wave) is measured from 0 to 2 PI. They show 3 separate cases. The first case is where the cosine wave is read linearly (that is, unmodulated). The wave is merely output as is. The second case is where the "reading speed" of the phase from 0 to PI is speeded up, while that of PI to 2 PI is slowed down. I suppose the modulator wave in this case would look something like a step function (positive, then negative). In the time domain, this results in the original cosine wave distorting into more of a sawtooth wave. The third example case is simply an extrapolation of the second case, where the reading speed is increased further before PI, and decreased further after PI. This results in much more of a sawtooth wave. These are of course, much simplified examples, since in the VZ, you can use sine or one of several sawtooth waves, with a wide range of wavelengths, as modulators. From the CZ manual: "The amount of distortion of the reading phase angle (depth of modulation) is determined by the momentary value of the DCW envelope [...the amplitude envelope of the modulator in the VZ...]". The iPD in the VZ (the *interactive* Phase Distortion) just comes from the fact that you can modulate the amplitude envelope of the modulator with a number of controllers interactively (works quite well too). As you may or may not know, the VZ arranges its modulator/carrier lines into 4 pairs per "voice". Within any one pair, the 1st line can phase distort or amplitude modulate the 2nd line, or can just be summed with it. The output of any of the first 3 pairs can be output directly, or used to phase modulate the next modulator/carrier pair. (The last pair is just output directly). Hope this helps. - Glenn From: defrain@en.ecn.purdue.edu (master guru) Subject: Re: Casio VZ info wanted Date: 23 Feb 92 17:45:48 GMT ... The VZ-10M has EIGHT stages which can be numerically and/or graphically edited. The sustain point can be positioned anywhere in the envelope as well as the end (i.e. one doesn`t have to use all eight parameters and waste time setting undesired points to zero). Are they "wonderful". Sort of. Actually programming them is a bit difficult -- the interface works on levels and rates (which is absolutely absurd IMHO). I would have preffered levels and times. Programming these is like defining a time function by manipulating its derivitive -- too indirect for me. Peaves... the envelopes cannot be looped -- they always finish!!!! What WERE the engineers thinking? Idiots... :-) ------------------ Paul D. DeFrain Purdue University EE box 145, 47907 From: dan@cafws1.eng.uci.edu (Dan Harkless) Subject: Re: Casio VZ info wanted Date: 4 Mar 92 07:45:38 GMT Tell it like it is, brother! Lemme hear you say Amen! I'd be a lot more apt to program sounds on my VZ-1 if the morons that designed this baby had made the envelopes loopable and had made them level/time, as you said. There's no way to get an envelope to hold a particular value for a period of time unless it's the sustain step, and you're holding the note. Even if you set several successive steps to the same level, it will stay at that level for but a microsecond, no matter what you set the Rate's to for those steps. And the closer the levels in two successive steps are, the less time you can have for the drop/rise from one to the next, no matter what you set the Rate's to. Pretty damn lame. ------------------------------------------------------------------------------ | Dan Harkless | "The sore in my soul | | dharkles@bonnie.ics.uci.edu | The mark in my heart -> Front 242, | | dan@cafws1.eng.uci.edu | Her acid reign..." Tragedy >For You< | ------------------------------------------------------------------------------