From: metlay+@cs.cmu.edu (Mike Metlay) Subject: A Review of the Waldorf MicroWave Date: 19 Oct 91 18:14:28 GMT DISCLAIMER 1: Well, this isn't REALLY a full review of the Waldorf MicroWave, but it's the best anyone is going to get for a while from ME. Trying to learn new gear while singlehandedly keeping a research group going and writing one's PhD thesis is at best a nontrivial task. In the month-plus that I've owned the MW, I've worked with it for barely ten hours. But those ten hours were enough for me to formulate some initial impressions to pass along, as I had promised. (Thanks to Neil Weinstock for booting me in the ass on this.) DISCLAIMER 2: This is a Metlay review. You should know by now what that means. No flames, people: I honestly don't care if you agree with my opinion of digital, sample-based Black Boxes (TM). So stuff it, okay? Now then: GETTING STARTED (AND DISCOVERING THAT YOU CAN'T, JUST YET) When you open the box, you find the MW itself, a set of optional stick-on rubber footsies if you aren't going to rackmount it, and no fewer than THREE manuals. One is the Performance manual, which explains the architecture of Single and Multi Patch organization, MIDI setup, and the things you need to know to get started. The second is the Programming Manual, which takes you inside the voice structure itself. The last and thinnest manual is the update for software rev 1.2x, whatever it is you get. Mine was 1.20; I understand that 1.23 is now shipping, which allows WaveSlave compatibility. The manuals themselves are a joy to use. Their only weak point is that they were obviously typeset on a Mac with very primitive software-- they look UGLY. However, Roland manuals are uniformly gorgeous, and aren't worth the paper they're printed on, so this is a minor point. The manuals are clearly organized, well-indexed, and loaded with useful data; the translation from the German was obviously done by either an American with German as a second language, or by a German who'd been speaking English for decades AND living in America for part of that time-- there are a number of jokes sprinkled through the manual, obviously aimed at an American audience (references to covering food before putting it inside wouldn't mean much to Germans). Each type of modulation has at least two examples given, that are musically sensible and clear to understand. I would instantly recommend this box, along with the Xpander (if you also had the MAtrix-12's manual, which is much better than the Xpander's), as a GREAT first subtractive synthesizer for the learner, just from the ability of the manual to communicate worthwhile knowledge. Having perused the manuals once through (I recommend this), you hook up your MIDI controller and turn on the MW. It CAN give stereo output from one of the two audio jacks, but the level is fairly low: it sounds much better through a sound system rather than headphones. The first thing you'll notice, as has been mentioned by Nick Rothwell and various other people, is that the presets are almost uniformly LOUSY. I mean, God AWFUL! They communicate NONE of the capabilities of this machine, and whoever programmed them should be shot in the throat and left to die. Playing one of these in a music store, with the presets the only available avenue of listening and something like an SY99 right next to you, is NO way to sell MicroWaves-- if I had heard it before I bought it, I would have saved my money. So, learn to initialize voices, and DO SO. Clear EVERYTHING and start from scratch, you won't be sorry you did. (At this point, a lot of the readership is saying, "You mean I can't just use it out of the BOX?!" No, you can't. I suggest that you go out and buy something more your speed, like an M1. Wankers.) This, of course, leads to the essential problem with the MicroWave, one that wouldn't be thought of as a problem as recently as 1980 but is now almost crippling: there is NO instant gratification. The unit either has lousy sounds, or no sounds. You can't start to enjoy playing it until you've enjoyed programming it first. If you can clear this hurdle, then the fun begins. If not, well, there's always the SQ-1. Gag. FINDING YOUR WAY AROUND The Micro's front panel is a bit sparse for my tastes, but the pages are organized in a fairly reasonable manner and the logic of the Micro's tree structure is a lot more snesible than most other synths out there. Basically you start with a 4x4 grid of pages, each with varying depths. They're grouped into four rows based on the sorts of activities you'll want to switch between (i.e. all the voice editing parameters are in one row, all the fast-edit parameters are in one row, etc.), so that you can jump around with minimum hassle. You choose your row with a big button marked MODE that cycles around the rows. Within each row, you pick a column (and hence a page) by punching one of four buttons. If the page you're looking at has several subpages (some do), then you punch the column button repeatedly to cycle through them until you find the one you want. Within each page or subpage, there are the parameters themselves, each with its own value. You access and change these with the red button and Big Red Knob (TM) over at the left side of the machine, by the display. The cursor will be either under the parameter or its value-- you use the button to move the cursor betwen the two fields, and the knob to dial in what you want. So, as an example, an edit to Filter Cutoff would be: Punch MODE until you're in the Voice Editing row (Row #3) Hit the second column button; if the display says VOLUME, hit it again Put the cursor under the parameter in the window, dial until CUTOFF appears Punch the red button, dial in the value you want. Sounds nasty, doesn't it? Well, I've got news for you: compared to trying to figure out where the up-arrow is going to put the cursor on the Wavestation's Mix-Envelope page, it's a CINCH. The interaction of the controls is logical and works exactly the same way for all actions on the synth (with some exceptions that make a lot of sense themselves); in less than a half hour, you'll be FLYING. Especially since when you're doing something like setting up Multi Patches or editing sounds, the number of keystrokes to get somewhere drops precipitously. I do not LIKE this setup-- I prefer a full front panel-- but it does work, and work well, as opposed to something like the SY77, ugh. VOICE ARCHITECTURE Each voice (there are eight) has two Oscillators driving two Wavetables running into a Filter and then to a Pan unit. The oscillators each have octave, pitch and detune (five octaves-plus range on each), pitch keyboard-track defeat, and two pitch modulation sources, one with a sidechain control and one straight in. The second modulator can be quantized for glissandi. Note that this is all just PITCH control; waveform control is in the Wave modules, that come next. The Waves have a common Wavetable (the unit comes with 32 and has room for 12 more) and individual Start Wave, Startsample, hardwired modulation settings for Wave Envelope, keyboard tracking, and velocity scaling, and two more modulators, one with a sidechain input. The stepping mode can be set smooth or stepped. Since the Waves are the most unique part of the Micro's sound, I'll talk more about them later. The mixer lets you blend both Osc/Waves with a white noise source; the mixer can be overdriven if desired. The VOlume page also has modulations for Volume envelope, velocity, keyboard tracking, and two general mods, one with sidechain. MIDI Controller 7 always controls overall volume. The filter is a four-pole lowpass analog filter with cutoff, resonance, modulation of cutoff by the Filter envelope, velocity, keyboard track, and two modulators, one with sidechain. The resonance also has its own mod source (As the manual says, "Yes, it can be done."), and goes into self-oscillation very nicely, thank you. The panning module sets a voice's stero position and has its own modulator. Normally voices are set to center in Single mode, but in Multis you have the option of spreading different Singles out a bit. MIDI COntroller 10 always controls voice pan, as an added modulation to existing ones. There are two LFOs. Each has rate control, shape and symmetry controls that provide many different waveforms (over 300 of them, actually), a rate-randomizer, rate and level modulators, switchable LFO sync, and a simple three stage envelope especially for LFO amount. There are three envelopes, labeled Volume, Filter and Wave. They are hardwired but defeatable to the pages named, and can also be sent anywhere else if desired. The Volume envelope is ADSR, the Filter envelope is DADSR, and the Wave Envelope is eight-time/eight-level with looping and variable sustain point. It can do either sustain or release loops, and has modulator inputs for times and levels. The Wave envelope has global modulation to all times and levels at once; the other envelopes have individual modulators and amounts for each stage. The unit also has Glide (equal rate or equal time, choosable), several temperaments including user-defined tuning tables, and can store names of up to 16 ASCII characters. There are also Macro and Fast-Edit pages. I won't describe them in detail, but they allow you to call up several preset envelope shapes and/or modulation types, enter them instantaneously, and modify them or existing envelopes/modulations with special screens (an exception to the normal editing modes) that let you fly in new values in a flash. If you're not interested in exactitude, and want to hack out a useful sound in a hurry, these modes make it easy. (And if you're a perfectionist, you always have the option of going in and tweaking the parameters in the regular edit mode.) STORING YOUR WORK The MicroWave has nine edit buffers. If you edit a patch and leave it to go to another patch, you do NOT lose your edits; they;re waiting there when you come back. This is LOVELY; I wish the Xpander did this. Even the VS's Review buffer must be manually saved before hunting around. So you can be editing up to eight patches at once! The column buttons double as a shift key and a set of three memory-management tools (Store, Compare, REcall); this assures that nothing involving memory can be done in the course of normal keypresses, and that a save or deletion is carefully premeditated. MULTI PATCHES AND MIDI Each Multi PAtch (like SIngles, there are 64) has one to eight Instruments. Each Instrument has its own Single Patch, MIDI Channel, key and velocity windows, velocity response curve, transpose/detune, temperament, volume and pan position (overlaying that of the Single patch itself).Each Instrument can be routed to the stereo outs or to one of the four individual outs. Each Instrument has its own MIDI input filters, and so on, and so on. Voice allocation is dynamic. There are four generic Controllers called CTRL W, X, Y and Z. These have different effects on each Instrument, but are assigned globally. In addition, the Micro understands Velocity, Release Velocity, Pressure (Mono AND/OR poly), Pitch Bend, and MIDI Controllers 1,2,7,10,64,65, and the numbers you pick for W,X,Y,Z. A few of these are hardwired: 7 to volume, 10 to pan, 64 to sustain, 65 to portamento switching (defeatable). Oh, I almost forgot. Glide can be in half-steps (glissando) if desired. My Micro currently understands everything in my rack, including the joystick on my VS and (if I get one) the four front-panel sliders on the Roland D-70. And the controllers can be routed anywhere.... WAVES A bit more detail is needed on the Wave modules. Here's how they work, sorta. Each Wavetable (there are 32 preset, 12 blank that can be loaded via MIDI by the user) has 64 Waves in it. OK so far? 32 Tables, 64 Waves. Now, of those 64 waves, the last three are always the same: 61 is a triangle wave, 62 is a square wave, and 63 is a sawtooth. But Waves 0 through 60 are DIFFERENT for each Table. Where these waves come from isn't important: some are stored in ROM, others are interpolated from the ROM Waves by an algorithm kept in a mayonnaise jar under Wolfgang Palm's bed and guarded by attack dogs. What IS important is that the MW is capable of shifting from Wave to Wave in real time, under tha control of any modulation source you wish! This can be a smooth shift or a stepped one: unlike the Wavestation, smoothing doesn't halve polyphony. Each Wave has its own unique character: there are smooth waves, grimy waves, ringing waves, blah waves, formants, transients, jarring noises. And they get even MORE character when swept around in Wavetables. Now, some sounds can benefit from using only one wave at a time; others might use a small range of Waves; using an etire Table isn't always the best thing to do, as the jumps from sound to sound can be jarring. What are the Tables like? Well, my notes aren't much help: "1 Hollow filter sweep sorta 3 Buzzy Inverted ring hollow !!!!! 4 Saw to Hollow and back? 5 Rectified? 10 high Feedback 12 Phonemish? 13 Evolution-- Animated! 14 Buzzy Rattly Bright!!! 15 Yanking Drawbars on the L-100 17 Multilooped Swell! 21 LEAPing OCTAVE resonances!!!!! 23 Hiccupping Organ twisty loop!! 24 Analogish filter Twist 27 Ragged S/H!! 28 Glittery Arpeg Filter with nasty tip 30 Beware of BIG THUNK at end!!" ...and so on. You have to hear them to understand. I could spend a year just trying different Wave setups in the same initialized patch, never touching anything else in the architecture. PERSONAL EXPERIENCES The unit is very forgiving of mistakes, with one small but important exception: if you switch to Multi mode in midsession, you CAN lose your edits if you're not careful. There's no volume control, except as an (admittedly fast-to-access) parameter in the grid. MIDI operation appears flawless, but Nick is hammering on his much harder than I do on mine, so it's not for me to say. Sustained notes don't quit when you switch programs, but on rare occasions they can hiccup momentarily. The buttons activate NOT when you push them, but when you LET GO of them --weird until you get used to it. The Micro's built like a tank, solid and heavy. IMPRESSIONS The MicroWave is not the ultimate synthesizer, or the ultimate anything. If it had four oscillators per voice with a vector joystick and an arpeggiator like the Prophet VS's, wave sequencing like the Wavestation's, and the modulation matrix and added features of the Xpander, then we'd REALLY have something. But let's not get ridiculous here. It does give you a hell of a lot of control, especially via MIDI. It's relatively bugfree -- I haven't hit a bug yet, and Nick has only reported a couple. And it sounds uh..... Hm. This is the part of the review I was dreading. How DOES it sound? Argh. Let me put it this way-- I have not yet (emphasis on the YET) come up with a sound that has sat me back in my chair, saying, "Oh, baby, THAT'S why I bought this machine!" Such an immediate, visceral response to the machine is important to me; in the past, I have gotten them from the modular drones and analog brasses and wild effects on my Xpander, the silky strings and hammering pads on my VS, and the gorgeous electric pianosynth on my EX-8000. But from the MicroWave-- nothing. YET! The difference was, that the other synths I've named were programmed by people rather than chimps, and were acquired back in the dim days before my doctoral thesis, when I could actually sit and work with my gear for days at a time without being distracted or feeling guilty. The Micro has so much depth and so much power that if I had some decent presets to at least HINT at where to start, and some time to really work with the machine, I KNOW I could get it to scream for me. But the patches I have created so far are heavy-handed and wearing, by and large. I need to learn to paint with smaller brushstrokes. I have created about a dozen patches so far. Some are tutorial in nature, designed to remind me of how the Wave Envelope looping works (by the way, Nick, I just got the bill for that panicky phone call to Scotland last month. You DON'T want to know!) or where waves are in the tables. Others are unimpressive; the strings are no good, and the wavescanned bass is rather slapdash. But there is also a burbling drone pad that sounds like the background to Edgar Froese's "Aqua," and a Moog Taurus that rattles the fillings.... I'm getting closer. Slowly, painfully closer, at a speed that is frustrating as hell. But my frustration, ultimately, is at MYSELF, for having gotten rusty. The Xpander and VS are like riding a bike at this point-- I sit down, I turn some knobs, I get the sound I heard in my head at the start. And to an extent, I can get the Micro to sound like an Xpander. But what's the point of that? I am trying to push BEYOND what my other gear can do, and THAT'S what is so time-consuming and agonizing. There IS something there; getting to it hurts me. So. My recommendations? They're fairly simple. The MicroWave costs about a thousand dollars. Basically it's an eight-voice analog synth with some digital tricks no other instrument can match and a great multitimbral MIDI implementation. Its presets stink, and should be cleared at once. It has no effects processing; I don't believe it needs it. If you want an analog synth with sonic and programming power, and you're not afraid of starting from scratch-- BUY THIS MACHINE. In these days of $1700 Xpanders, $1000 Prophets and $1200 MIDIed Minimoogs, it's an absolutely unbeatable buy. For your money, you will not find more power (whether that power is audio or MIDI). If you need gooey effects and nice realistic presets, buy something else. Now if you'll excuse me, I'm not going to be able to sleep tonight if I can't get this (^@&#%$#*! string patch to work.... -- metlay | "Be careful-- you really don't want to the leader of the gang, er, Team| snap off your wanger in the midst of a | performance." metlay@organ.music.cs.cmu.edu | --sound advice from the Nickmeister From: nick@dcs.ed.ac.uk (Nick Rothwell) Newsgroups: rec.music.synth Subject: Re: A Review of the Waldorf MicroWave Date: 21 Oct 91 11:40:30 GMT >Let me put it this way-- I have not yet (emphasis on the YET) come up >with a sound that has sat me back in my chair, saying, "Oh, baby, THAT'S >why I bought this machine!" Such an immediate, visceral response to the >machine is important to me; in the past, I have gotten them from the >modular drones and analog brasses and wild effects on my Xpander, the silky >strings and hammering pads on my VS, and the gorgeous electric pianosynth >on my EX-8000. But from the MicroWave-- nothing. YET! Give it a couple of months. That's how long it took me. I spent a couple of months programming up blah sounds and then started to get the "Oh, yeah, now *that's* what I'm after...!" patches once I started to get to know my way around. >I need to >learn to paint with smaller brushstrokes. I would reckon that this is the case. It's surprising how the machine jumps to life once you start adding some subtle animation (pitch especially). Detuning is essential, I find, since the wavetables tend to be very bright harmonically, and this is the best way to animate them. The other thing is to become familiar with the wavetables: there's often a tiny segment of four or five waves buried somewhere in one table that's wonderful for a particular effect. >It has >no effects processing; I don't believe it needs it. It certainly doesn't need any onboard effects (cf. the wavestations of this world which require harmonically-enhanced phasing choruses to plug the deficiencies of the architecture). I tend to sit my MicroWave in a fairly high, but clean and thin, reverb setting, and chorus it gently as well. More than that and the sparkling high-end punch tends to get lost. The machine's main weakness seems to be bass. The wavetables start to fall apart in the lower registers and I haven't managed to make the machine rumble in any satisfactory way. But, I'm happy using my MKS-70 and D-70 for bass anyway. -- Nick Rothwell | "That's the Waldorf MicroWave set for General MIDI." LFCS | "EEEEEIIIIAAAAAOOOOOOUUUUMMMM ZUMZUPZUMZUPZUMZUP..." Edinburgh University | "Is that `STRINGS 1'?" nick@dcs.ed.ac.uk | "Yeah. You got a problem with that?" From: hary@well.sf.ca.us (Joseph Hary) Subject: Re: microwave Message-ID: <27023@well.sf.ca.us> Date: 31 Aug 91 20:59:14 GMT In all the comparsions of the microwave to the wavestation and other istruments, something seems to be missing: The microwave has an unique sound that you cant achieve through wavetable playback of a string of samples. In fact, in a microwave there are only about 15k bytes of sample memory -247 waves of 64 bytes each. The wavetables in a microwave consist of pointers to these waves. Now the unusual and powerful action of a microwave oscillator is to use these waves as starting points and to interpolate among the spectra of adjecent waves. A wavetable may only point to two 'real' rom based waves and the microwave will create 58 new waves that will interpolate between the spectra suggested by the rom waves (the same holds true for user waves downloaded into ram). Depending on how you set up a wavetable, you can go for a wild ride through timbre space. The unfortunate thing about the microwave is that they did not provide a means to edit the wavetables using the front panel - you have to develop software to edit the waves. I find that wavetable editing allows me to specify a basic 'spectral' envelope that can simulate real instruments or create fanciful ones. The interpolation algorithms frequently generate inharmonic partials which create that bell-like tone. Overall, the microwave feels like a musical instrument rather than a computer to me - because of the ease of timbral manipulation. -Joe From: metlay+@cs.cmu.edu (Mike Metlay) Subject: Re: Vector Synthesis vs. Waveshaping? Date: 13 Dec 91 02:47:30 GMT In article <16750.2946c219@amherst.edu> ljnelson@amherst.edu (Starbuck) writes: >Quick question here: is there a difference between these three synthesis >techniques: > o Waveshaping > o Wavetable Synthesis > o Vector Synthesis >..or are they three different companies' trademarks for the same technique? I >understand Vector Synthesis; a friend of mine has an SY22 that I've done some >patches and sequences for. The Korg and the Waldorf names elude me, though. No, they're all different. QUITE different, in fact; I can help understand the distinctions between Wavetable Synthesis and Vector Synthesis, as I own one of each. VECTOR SYNTHESIS is a trade name coined by Sequential for a system whereby four oscillators can be mixed simultaneously in real time by a joystick. Put one at each corner of a square, waggle, and there you are. The idea of a graphically-displayed mix envelope where each point represents a point on the Cartesian plane extends the concept to repeatable effects rather than realtime wanking. The Prophet VS, SY22, and Wavestation all use a vector joystick-- the VS and WS use it to mix waveforms, and the SY22 can use it to mix between detuned versions of the same waveform (the VS and WS can do this as well, but they make it easy for you on the SY22.). This allows for timbral evolution that can either be drastic or very subtle. If the machine has transients and sustained tones available, vector mixing can easily emulate Linear Arithmetic synthesis. The simple detuned-mixing of four identical waves produces sounds of utterly obscene thickness. I discovered it for myself one day when I said to myself, "Well, if the VS has Curtis Filters, why not just put a plain old sawtooth wave on all the oscillators and see what I get? And while I'm at it, I'll detune them all a bit and vector between them...." The resulting sound is now my absolute favorite string pad anywhere, and has gotten comments like "Oooh, I *like* that" (nick) and "Where did those lovely strings come from?" (adam). Vector synthesis satisfies all the criteria for a useful technique: it's easy to start with, deep to master, intuitive, and sounds great. WAVETABLE SYNTHESIS is the process by which the Waldorf Microwave and the PPG before it created sounds. Within the Micro's memory are some 250 waves, each a half cycle consisting of a certain number of data words. (The total memory required is TINY.) They are organized into wavetables, which consist of a list of addresses (61 per table) with each address containing either a wave or a blank space. For instance, a simple wavetable might say something like: "Space number 1 has Wave 27, space number 38 has wave number 172, and space number 61 has Wave 40." The spaces in between those points in the table do not contain actual waves themselves-- they contain INTERPOLATIONS between the waves nearest them. So if you were to listen to Wave 1 in the table you would hear ROM wave number 27, and if you were to listen to wave number 38 in the table you would hear ROM wave 172. BUT if you listen to wave number 19 in the table, the Micro says, "Hmm, he wants wave 19. But there IS no Wave 19. Well, what's nearby? Ah, Wave 1 has a ROM wave in it-- number 27. And, ah, let's see here, Wave 38 contains ROM wave number 172! So the wave he's asking for is HALFWAY between those two ROM Waves, which would be....*calculate calculate calculate* ...THIS." And it feeds you, INSTANTLY, a harmonic interpolation between those two ROM waves-- a totally new waveform with characteristics of each of its parents. But if all it did was act as a memory-saving trick, it wouldn't be half as nifty as it is-- because the Micro can do those interpolation calculations so FAST, that you can choose a wavetable and tell it to scan the table >from Point A to Point B, and it'll play a waveform that CHANGES its harmonic structure in real time according to your orders. You can sweep a table one way, both ways, periodically, back and forth in uneven steps with a multistage envelope, or stick to one wave if that's all you need. The Micro has 30 wavetables with 61 waves in each, and each table can be traversed in any order with any starting point, with the two oscillators sharing one table but travelling it in two different directions. And THEN you have a filter, amplifier, LFOs, envelopes, and so on, AFTER you choose what the oscillators do. Most of the programming I've done so far on the Micro has been with no filter mod, no envelopes, nothing. Just messing with the wavetables and listening to them evolve..... Wavetable synthesis is very VERY powerful. But it is NOT intuitive, and it can be very hard to master. However, the 30 tables have their own landmarks and recognizable sections, and after a while one gets used to grabbing sections of tables to fit one's needs: noises, formants, organ tones, crunchy bits, etc. WAVESHAPING is a technique which has never been adequately explained to me. >From the stuff I've heard, it IS a real academically interesting technique but is either poorly or incorrectly implemented on the 01/W. I should also point out that WAVE SEQUENCING, as found on the WS, has a lot of power of its own-- it IS fast enough to do granular synthesis, if you're REALLY patient with your programming. Hope that helps. -- metlay | ninetyeight digital synths in the rack just another guy with an Xpander | ninetyeight digital synths | * KEYBOARD CALIBRATION FAILED * metlay@organ.music.cs.cmu.edu | ninetyseven digital synths in the rack From: metlay@minerva.phyast.pitt.edu (metlay) Subject: Re: Microwave basics Date: 12 Feb 92 17:51:53 GMT The Waldorf MicroWave is a 2U rackmount synthesizer module with eight voices that can be operated in homophonic or multitimbral modes. The voice architecture consists of two digital oscillators (q.v.), an analog VCF, three envelopes (one multistage loopable), two LFOs and a few other goodies, per voice. MIDI control over most parts of the architecture is quite flexible and powerful. The oscillators themselves use a form of digital lookup called "wavetables," where a series of waves are interpolated in a list of gradually changing harmonics, in a fashion controllable by envelopes, LFOs, etc. This allows the actual waveform output by the oscillator to change in real time before any synthesizer modification of the wave occurs, lending an extra dimension to sound shaping. The unit is a MIDIed, rackmountable version of the old PPG Wave 2.3, which was around in the early 80s, minus its sampling setup. The Micro is relatively well laid out, cleanly designed, sturdy, and quite handy with MIDI. Its basic sound generation circuitry is clean and free of nasty glitches, and there exists a fair amount of latitude as to what one can do with the basic building blocks of sound. I own one, but have had little time to really get at its guts as I might wish to. I do, however, regard it as a superior use of one's studio budget to buying an analog synth that's been MIDIed and rackmounted. Others have had more time to work with theirs; you should ask THEM about why it's owrth keeping around.... -- metlay | The Jupiter-8 is a pre-MIDI polysynth, | The Jupiter-6 is a proto-MIDI polysynth, | The Jupiter-4 is an old preset/prog. synth metlay@minerva.phyast.pitt.edu | ....and The Jupiter-2 is a FLYING SAUCER?! From: schabtac@STOUT.ATD.UCAR.EDU (Adam Schabtach) Subject: Wavetable modulation (was Re: Digital synth project) Date: 23 Feb 92 05:46:44 GMT > Now let's say > we had a wavetable which consisted of a lot of sinewave samples strung > together at increasing frequencies. Modulate the lookup into this table > with another waveform and voila, FM synthesis. Not exactly, I don't think. Note that you have to put sine waves whose frequencies are integral multiples of the fundamental in the tables. If you don't do this, the waves won't be sine waves -- they'll have an extra chunk of the sine shape in each cycle. (Does that make sense? This would be *much* easier to explain if I could draw a picture.) Hence as you modulate the wave lookup, you'll play waves that have a lot of harmonic content that sine wave don't have. This won't necessarily sound bad, but it won't sound like a sine wave being modulated. > Another wavetable-based synth is the Microwave, a descendant of the PPG > synth. It lets you pick two wave in a table and then gradually moves from > one to the other, interpolating the changes as it goes. Also a very powerful > synthesis method. In fact, the MicroWave has a much more flexible architecture than this. It has "wave control tables" which are 60-entry arrays of pointers to waves. A pointer can point to one of several hundred waves in ROM or RAM, or point to NULL (more or less). If the pointer is NULL, the wave for that entry is interpolated from the waves to either side. So in a simple case you could have the first entry point to a sine wave, the last point to a square wave, and all the rest NULL. As the lookup position is modulated, you'd hear a wave that evolved from a sine to a square (or vice versa, or both, or whatever depending on what you're modulating with). In a more complex case, you'd have a number of pointers pointing at different waves throughout the table, so as you swept through the table you'd hear all sorts of timbral changes. It's just the same as the VFX architecture, except that the VFX doesn't let you change the wave control table. --Adam schabtac@stout.atd.ucar.edu