Mark Jenkins reports on this recent addition to the popular CZ range of polysynths and suggests that the Phase Distortion synthesis it employs could well be the answer for those of you caught in the 'analogue versus digital' dilemma.

Well now, we can't start this review by saying that Casio aren't accepted by professional musicians. Eighteen months ago the company faced just that very problem, mainly because they were still associated with 'toy' home keyboards in the minds of many serious players. But nowadays, although Casio are still making forward strides in home keyboards, it's the pro keyboard manufacturers who have adopted a well-justified "let's see what Casio do first" attitude.

That attitude was born when Casio launched the CZ-101, the tiny Phase Distortion synth which overnight established the company as a pro keyboard manufacturer. Because although the CZ-101 is small in stature, it's got a 'big' sound - one which is expanded and improved on by the new CZ-3000.

So a few words to begin with on Phase Distortion (PD), Casio's proprietary sound creation system used on all the CZ synths and on many of their new home keyboards. It's not analogue - Casio's experience lying more in the digital realms of calculators and LCD watches - but it isn't digital in the same sense that Yamaha's DX synths are digital.

Wisely, Casio wanted to create a system which captured the best of Roland's analogue sounds and Yamaha's digital sounds, but the latter company's FM process is patented and so couldn't be used. In any case, the argument went, a lot of players are put off by the jargon of FM - 'operators', 'algorithms', 'carriers' and 'modulators' - and by the 147 parameters needed to define a sound on, for example, the Yamaha DX7.

So Phase Distortion is something of a compromise, offering much of the power of FM but with a terminology more or less based on familiar analogue synthesis. While FM works by modulating sine waves against one another, PD creates tones by modifying the readout pattern of a sine wave stored in ROM by varying amounts to create its complex oscillator waveshapes.

The great advantage of PD is that it's easily approachable. There are recognisable banks of oscillators (DCOs), selectable waveforms (eight complex ones rather than the two or three simple ones typically found on an analogue synth), multi-stage envelopes, amplifiers and effects such as Noise and Ring Mod. The CZ-3000 is particularly approachable because it has a large table summarising the main parameters on its right-hand side where the CZ-5000's sequencer was once located.

For yes, it has to be said-the CZ-3000 is basically a cut-down CZ-5000, losing the eight channel multi-timbral sequencer which acted, in effect, as two SZ-1 sequencers together. Now as far as I know, the CZ-5000 hasn't exactly been a massive seller, probably because it looks a little old-fashioned and unapproachable, and because the onboard sequencer is rather daunting to use. However much effort you put into it - composing in real-time or step-time, assigning voices to tracks and carefully editing sections - in the end, all the voices come out of a single pair of jack sockets anyway, so it's hardly a professional recording tool.

Dumping the sequencer has made the CZ-3000 a little neater and given the opportunity for a slight cosmetic upgrade. Most of the battleship grey has gone, to be replaced by a glossy black finish which makes the synth look like it's built from ebony - very plush. The same horrible grey tablet pushbuttons are still there though, so the CZ-3000 continues to have a rather chunky, unsleek appearance.

Also absent is the tape dump facility found on the larger CZ-5000. In its place you have a MIDI Thru socket which wasn't there previously, but that doesn't make up for the fact that buying RAM cartridges all the time to store sounds is mighty expensive. If you've got a computer, there are some excellent CZ-Series editor packages about at the moment, including the one from Steinberg Research, but they're aimed principally at the CZ-101 and CZ-1000. Nevertheless, these could allow you to build up a sound library, cheaply, on floppy disks and also help clarify the difficult parts of PD editing, into which we'll now plunge.

SOUND EDITING

32 of the Casio's 64 memories are programmable, the rest being preset and only susceptible to temporary editing. Sounds are called up using four banks of four pushbuttons - Presets A-D, and Memories A-D, combined with sound numbers 1-4 and 5-8. Loading is instantaneous.

When you want to edit a sound slightly or drastically, you turn to an LCD display in the centre of the front panel. This shows names for the Preset sounds, bank and patch numbers for the Programmable sounds, and parameter levels when you're editing. To begin editing a parameter all you have to do is punch the appropriate button - such as DCO 1 Waveform, or Vibrato Level, or Modulation Depth. Once you do this, the LCD display changes to show the current level of the parameter. For instance, if you hit DCO 1 Envelope on the first preset, a brass sound, the obtained readout is "Pitch Step 1 *** Rate=99 Level=33".

Now this particular display sounds a bit intimidating, but it only means that the facility you're altering is defined by more than one parameter. In the case of the Pitch Envelope function, you can alter the pitch of the sound with any stage of an envelope to create gliding or bend-type effects, and this display is simply saying that the first envelope stage of the brass sound has a very fast, quite deep, pitch-bend on the first oscillator bank.

When there is more than one parameter on view at a time, you need to be able to select the one you wish to alter. This is done with two cursor buttons which move a flashing line from beneath one display to the next on the LCD.Then you use a pair of Up/Down value keys to alter the exact setting.

Some display readouts are more complex than others. 'Octave', for instance, simply gives you "Octave Range = " and then a choice of +1, 0 or -1. 'Portamento' simply gives you a Portamento time, while 'Glide' gives you a note value (how far from the key depressed the glide starts) and the time taken for the glide to finish. If you push any parameter button after you've finished altering that parameter, you'll go straight back to the sound name display and you'll hear the sound playing in its newly modified form.

It's also possible, using the Compare/Recall button, to return to the original form of a sound you've altered to make sure that your new version is, in fact, better than the original before you commit it to memory.

So just how easy is it to come to terms with PD editing? The basic excitement of the sounds lies in their being able to change from one waveform to another during the course of a note - a process carried out in a more primitive way on analogue synths using a filter. On the CZ-3000's waveform display for DCO 1 and DCO 2, you can start on any of eight waveforms and finish on any other at the end of the note. Some of the waves are familiar - Wave 1 is a Sawtooth, 2 is a Square, 3 a thin spike - but some are more exotic. Wave 4 is a spike followed by a sine wave (double sine), waveform 5 is a section of a sine wave with a sharp cut-off (saw-pulse), and waveforms 6-8 are highly active resonant forms with differing overall shapes: sawtooth, triangle and trapezoid. Incidentally, only one of the resonant forms can be used at any time, although the others can be combined at will to give 33 different waveform options.

Since the CZ synths sweep between waveforms, they don't need a filter, which is the main difference from a standard analogue synth. Like the DX7,there's an easy way into editing CZ sounds. On the DX7 you just change the algorithm, the 'patch' which defines the order in which the oscillators (operators) modulate each other. On the CZ, you just change the start or end waveforms to come up with something slightly (or completely) different from your original sound, then proceed from there.

Another way of introducing rapid change to the voices lies in altering the Line Select function. This allows you to listen to DCO 1, DCO 2, DCO 1 with 2 modulated, or DCO 1 with 1 modulated. Modulations available are Ring Mod and Noise Mod, the former useful for clangy, metallic sounds, and the latter for percussion, wind and surf simulations.

COMPLEX ENVELOPES

The most complex section of the CZ-3000 is the envelope generator, which has its own editing controls and right-hand graphics to aid familiarisation. From the envelope chart you can see that the design uses several stages - Attack, Decay, Attack 2, Decay 2, Decay 3, Sustain, After-Attack, Release 1, and Release 2. Obviously this envelope can produce complex sounds, particularly when you consider that envelopes can be applied to the pitch, waveform and volume of each oscillator bank. But you aren't always going to want this degree of complexity, which is why the Envelope Step buttons that select the envelope stage you're editing are accompanied by Sustain and End Point buttons. If you want the envelope only to have four stages (ADSR) like a conventional synth, you just hit End while editing Stage 4. Similarly, the Sustain function can be placed at any envelope point you like.

Since you can have all sorts of strange envelope effects - such as new Attack stages taking place even after you release the keys - you can define tremendously complex sounds which respond in different ways to different playing styles, modulating in one way if held and in another way if released, for instance.

TYPICAL SOUNDS

Now that you know how to fix up the sounds if you don't like them, it's worth looking through the presets to see what's on offer. And the answer is - exactly what you'd expect - a good combination of analogue-type and FM-type noises, a few unique effects which only the Casio could produce, and a few horrors which hark back a little too much to the days of their pocket-sized VL-Tone.

The Preset memories offer Brass Ensemble 1 (a fine, rich chordal sound), Synth Brass (sharper and twangier), Brass Ensemble 2 (livelier with more movement) and Trumpet (a reasonable solo sound), followed by ensemble and solo string sounds to which similar comments apply; then there's Jazz Organ (heavy!), Electric Piano (reasonable), Accordion (really like an accordion) and Fantastic Organ (not fantastic). Then on to wind sounds with Whistle (straight out of Tomita), Flute (dull), Blues Harmonica (straight out of Keith Emerson) and Double Reed (quite powerful). Handy Fat Bass and Synth Bass sounds are followed by Electric Guitar (a powerful fuzzy sound for chord work) and Metallic Sound (quite DX7-like).

Then we really get into DX7 territory with Vibraphone, Crispy Xylophone, Synth Glockenspiel and Marimba, all metallic percussive sounds which have much of the piercing effect of FM. Not quite as sharp, but then, an analogue synth couldn't come close to producing these effects. Synth Drums, Steel Drums, Synth Percussion and Conga are reasonable, while Human Voice is useful as a background wash. Fairy Tale is a charming tinkly little sound, whilst Carillon is a modified Marimba, and Typhoon is - well, a typhoon!

The programmable memories on the model we had for review were full of all sorts of peculiar effects, many of them from the Prophet 5 school of twangy filter treatment. Some imaginative use had been made of the Pitch Envelope, with one sound in particular bending up and down a semitone on each note in imitation of some kind of Japanese stringed instrument. Very impressive.

With all this control over waveforms and pitch envelopes you'd expect the CZ-3000 to sound something like a PPG, which to some extent it can. You don't get the same random wavetable sweep effect as on the PPG because the waves are always swept smoothly on the Casio, but there are some excellent sounds to be had with all sorts of internal movement, arpeggio-like effects with octave jumping, and much more.

On to the performance controls of the 3000, which on the whole are pretty professional. A sprung Pitch Bend wheel and unsprung Modulation wheel with On/Off button are placed to the left of the keyboard but, of course, are no substitute for the lack of velocity or after-touch response. Surely Casio must have a velocity-responsive synth on the way, now that they've developed a touch-responsive keyboard for their new piano range?

Also switchable are the Portamento and Glide functions, Key Transpose (adjusted on the LCD display) and Solo functions for monophonic playing. Then there's Tone Mix and Key Split, two powerful performance modes which can make the Casio sound even more impressive.

Normally the CZ-3000 is eight-note polyphonic (single oscillator sounds such as Flute and Violin can be sixteen-note polyphonic) but in the Tone Mix mode it's four-note polyphonic with two sounds layered over each other, and in the Key Split mode it's dual four-note polyphonic with an adjustable split point.

The Tone Mix and Key Split modes are marvellous, but they're a little difficult to get into. You can't have a programmable pair of sounds or splits, so the split point remains the same whatever combination of sounds you choose until you purposely change it. You can balance the levels of the layered sounds in Tone Mix mode, with the cursor deciding which sound you're working on, and in Split mode there's also a display of the note value of the split point (which shouldn't be confused with the MIDI note value).

But these modes are slow to use on stage, which is a shame, because the layering of analogue-like strings and digital percussive effects can work well live. Similarly, the MIDI possibilities of a split Synth Bass/DigiBrass patch are enormous, so it's a shame that Casio don't provide split patch memories as Roland do on their Jupiter 6.

MULTI-TIMBRAL MIDI

However, the MIDI options of the CZ-3000 do have more to offer. As with the smaller CZ synths,the machine can play multi-timbrally, assigning different monophonic sounds to different MIDI channels. Send and Receive channels are independent and the machine responds to Key Data, Portamento Time, Master Tune, Portamento On/Off, Sustain Pedal, Patch Number, Pitch Bend, Local Control On/Off and System Exclusive (patch) information.

However, if a second number is inserted after the MIDI Receive Channel number, some of the voices will become monophonically controllable on consecutive MIDI channels. For instance, CH1 = 01 ( 0 ) will simply give polyphonic playing on Channel 1, but CH = 03(4) will give independent monophonic playing of four voices on channels 3, 4, 5 and 6, leaving four voices spare for live playing.

Assigning the sounds used for any MIDI-controlled channels is relatively simple, although again it's impossible to quickly set up a patch for live use. In fact, you have to use a MIDI cable to connect MIDI Out to MIDI In, then select each patch after you've chosen the MIDI channel it should respond to - in other words the CZ-3000 has to 'tell itself' via MIDI which sound memories are needed.

The CZ-3000's value as a multi-timbral MIDI expander is a little limited, because as usual there's only a single pair of outputs (stereo left/right) provided on the rear panel. While we're looking at the rear panel we could point out the headphone output, Right-Mono and Left jack outputs, Foot Volume jack. Sustain pedal jack, MIDI In/Out/Thru, Memory protect On/Off switch, RAM cartridge port and Euro mains socket. And as far as the front panel is concerned, we haven't yet mentioned the sliding Volume control and Chorus Depth control, the chorus being non-programmable.

CONCLUSIONS

Time to come to some conclusions about the CZ-3000. Firstly, it's not the most futuristic-looking synth on the market, a fact which may put some prospective purchasers off even listening to it. Casio still need a little work on the styling.

Secondly, some of the major advantages of the unit - such as multi-timbral playing - are partly offset by annoying omissions, such as the lack of independent voice outputs found on the Oberheim Xpander and E-Mu Emulator II. Perhaps these could be added by an engineer in a worthwhile (though guarantee-busting) modification?

But on the whole, the CZ-3000 is very pleasing to use. The major advantage of going for any Casio synth is the provision of both analogue and FM-type sounds, coupled with a good (though slightly hissy) stereo chorus. Overall, the synth's well-constructed and should give excellent service.

For the starter torn between analogue and digital sounds, at £675 the Casio is the obvious solution. The more experienced player is still more likely to go for the CZ-101 and use it as a compact expander for an existing synth, but the new CZ-3000 deserves to be seen on more stages and in more studios than has the CZ-5000. We're still looking forward to a touch-sensitive model though!

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