The charge: that Yamaha's DX9 FM polysynth has been unfairly neglected by most of the electronic music fraternity whilst most of the emphasis has been placed on its more expensive relative, the DX7. Speaking for the prosecution: Steve Howell.

Unless you've spent the last 18 months or so in a Tibetan monastery you will no doubt be aware that Yamaha, after an apparent disappearing act, recently released a range of electronic keyboards that utilised a technique of sound creation called 'FM Digital Synthesis'. These keyboards come in the form of two incredible console organs, two electric pianos, two preset polyphonic keyboards and, most importantly perhaps, two user-programmable polyphonic synthesisers - the DX7 and DX9. These keyboards are the result of years of research in the field of FM synthesis which originally produced the GS1 and GS2 but, in the DX synthesisers, Yamaha have brought what was once the province of the wealthy megastar into the hands of more ordinary folk, and such are these instruments' capabilities that many of the aforementioned stars now have them alongside their Fairlights, which only proves that they are not a poor man's compromise for 'the real thing'.

There is one problem, however. It takes a bit of readjustment to create sounds with them if you're used to using analogue techniques of filtering and shaping existing waveforms but, believe me, it's not that difficult if you approach the procedure logically. It's not a technique that lends itself to the 'let's-have-a-fiddle-and-see-what-happens' attitude, but then again that's not necessarily such a bad thing. But I'm not here to impart the whys, wherefores and wonders of FM programming as that is already adequately covered in our 'Understanding the DX7' series of articles.

Instead, I propose to give you my impressions of the DX9. Now, this is possibly the first full review you've seen of the DX9 as it has received little more than a passing mention in the music press, while all and sundry have been foaming over the DX7. However, having owned a DX9 for about six months now, and having used a DX7 on many occasions - I feel there is much to be said in favour of the DX9. So, let the review begin...

Background

The DX9 is a 16-voice, programmable FM synthesiser. It has four Operators per voice which can be patched together in various configurations via eight algorithms. Each Operator has a digital sine wave oscillator, an eight-stage envelope generator and associated VCA, and the user has complete control over coarse and fine frequency, detune, the four envelope rates and levels, LFO modulation level of the oscillators and VCAs, along with the delay and waveform selection which gives sine, triangle, rising and falling sawtooth, square and random sample and hold. Each Operator has variable key and rate scaling which affects each Operators' output and envelope shape over the range of the five-octave keyboard. You can switch through the eight algorithms and adjust the feedback loop (which can be used to create sawtooth waveforms and, with extreme settings, white noise) and all of these parameters can be stored in 20 memories which can be permanently or temporarily edited at will.

There are also numerous 'Function' buttons which allow a wide range of control over pitch bend range (up and down a maximum of one octave), portamento, mono or polyphonic keyboard modes, and vibrato, tremolo and tone colour, using either the modulation wheel or the optional breath controller. Loading and saving sounds on cassette is also possible. As on the DX7, all these functions are memorised, but in this case they affect all the sounds, and cannot be assigned to individual voices - you have to buy the £10,000 DX1 for that facility.

Programming

Programming is theoretically quite straightforward. You press 'FUNCTION' and 'VOICE INIT' and the LCD screen will ask you 'ARE YOU SURE?', to which you answer 'YES' using the incrementor button to the right of the data entry slider. You will then be assigned a portion of buffered memory on position '0' (shown on the red LED display) and you now have control over all the voice parameters (purple) labelled beneath the memory selectors (turquoise) and adjustments are made with either the data entry slider to the left of the front panel or with the incrementor buttons. When you've successfully(!) created your sound, you can store it simply by pressing 'MEMORY SELECT' and 'STORE' and an appropriate memory position only, and you can also turn Operators on and off temporarily (this feature is not programmable) to home in on certain elements of any sounds for comparative purposes.

Should you wish to edit any of the 120 sounds that are supplied with the DX9 (or indeed one of your own) simply press the purple 'EDIT/COMPARE' button and you can alter any of the voice parameters in the same way as you did when creating a sound. If you want to compare the edited version with the original you simply press 'EDIT/COMPARE' again and the red LED will flash: you can then hear the original sound. Should you accidentally lose your half-created sound by pressing Memory Select and selecting a memory when you meant to bring in another voice parameter (and believe me, it's easily done!) you can retrieve it by pressing 'FUNCTION' and 'EDIT RECALL' and, as with 'VOICE INIT', you will be asked 'ARE YOU SURE?' to which you answer 'YES': you will then be given your edit exactly where you left it. This feature also works when you switch the instrument off, so should you wish to recall a particular edit a few days later, and provided you haven't edited anything else in the meantime, 'EDIT RECALL' will give you edit at the point where you left off - damned clever, these Japanese... Should you wish to store an edited sound, you proceed as before and press 'MEMORY SELECT', the pink 'STORE' button and an appropriate memory location.

As already mentioned, the DX9 gives the facility to store up to 20 sounds and, although this is by no means a massive amount by today's standards, it's quite enough for most purposes especially if, like me, you only work in studios. You can, however, store your sounds on cassette, and this is done using the 'FUNCTION' buttons and, as with other functions, the LCD screen will guide you politely through the procedure, so it's all quite user-friendly. It takes about 20 seconds or so to load and save the full memory and you can either load sounds into the synthesiser en masse (ie. the full memory of 20 sounds) or you can load them singly, which is handy - if only you could save them one at a time as well.

Beware, though. If you've just made up some sounds but haven't saved them on cassette, loading in new sounds will write over them and they'll be lost forever, so it's wise always to save sounds on cassette for safekeeping.

So, with that technical resume out of the way, what are my impressions of the DX9? I love it. It's one of the best synthesisers I've used. It can sound extremely 'expensive', very 'acoustic', breathtakingly delicate and also quite aggressive (although as with the DX7, recreating analogue synthesiser sounds is not its greatest virtue). It also has MIDI In, Out and Thru, but although it works well with other MIDI keyboards, I've experienced some problems with MIDI sequencers (naughty!). It also looks and feels good.

The Comparison

One question still remains, of course, why should anybody want a DX9 when for a few pounds more they can have a DX7?

It must be said that the more expensive Yamaha does have a little more in the way of facilities than the subject of this report, and in most cases I suppose it'll simply be a question of whether or not these facilities matter sufficiently to the individual purchaser. However, it's my belief that a number of the DX7's advantages are not quite as significant as they might at first appear.

Perhaps the DX7's most promising feature is its touch-sensitive keyboard, something that accounts for quite a fair proportion of the price difference between these two FM synthesisers. Sensing of initial key velocity is extremely useful, but it's my contention that, unless you're a keyboard player whose early training was on classical piano, you'll find touch-sensitivity a feature that's not as frequently used as you thought it would be. Many of the DX7's factory presets don't lend themselves particularly well to manipulation by a touch-sensitive keyboard, and although the after-touch facility is in theory a useful one, in practice the standard Yamaha breath controller is a more precise way of controlling things. You'll probably have guessed by now that I'm not a piano-trained keyboard player, but you get my point.

The DX7 also incorporates more elaborate key and rate scaling than its cheaper brother, but every time I've used a 7 I've found their effects fairly subtle. Besides, on many of the 7's factory voices, scaling is set up so that it sounds identical to the sound's equivalent on the 9, while the extra variability this feature provides can cause the user some confusion at the programming stage. So, another feature I could probably live without...

Operators

The DX7 has six of these as against the cheaper synth's four, which - theoretically - should be quite a major difference. However, I've transferred a number of patches from a friend's DX7 onto my own instrument, and believe me, even if an oscilloscope can tell the difference, your ears probably won't!

On the algorithm front, the more expensive Yamaha has a lead of 32 to 8 - not a difference to be taken lightly, you might think. Well, I suppose it must be said that having that number of algorithms does give you an awful lot of operational flexibility but, again, one important point to bear in mind is that some of the 32 are very similar to each other and that, in case you hadn't noticed, all eight algorithms on the DX9 have rough counterparts on the 7, so that as with the Operators themselves, the different configurations available are sufficient to enable 'copying' of voices from the 7 to the 9 without too much in the way of audible discomfort.

Memory

The two DX instruments differ not only in the number of patch memories they provide but also in the way those patches are stored.

If you're going to use your FM synth for a lot of live work, the DX7 scores over its less expensive counterpart because you can have up to 96 sounds instantly recallable from cartridge. In economic terms, however, building up a library of your own programs on the DX7 is an expensive business because Yamaha's RAM cartridges cost £40 each, while ordinary audio cassettes - which are what the DX9 uses - are rather cheaper, particularly when you consider that one C60 cassette is capable of storing literally hundreds of presets, whereas one RAM cartridge stores only 32.

There are a few other detail differences between the two DXs. One thing the 7 does offer that might conceivably be of use to a few musicians is the provision for giving user programs names. This can be useful (particularly if you find yourself programming morning, noon and night), but unless you've got an overtly hard-working imagination you might have trouble thinking of appropriate patch names in the first place, and then you've got to go through the rather tedious process of trying to remember which names you gave to which sounds. So, a handy luxury, but by no means an essential fitment.

In fairness, though, I should just mention that DX7's footpedal control which really is a nice feature that I for one would like to see included in the DX9's spec also (come think of it, I can't understand why Yamaha haven't already done this: can it really be that expensive to incorporate?), but even this failing is made up for in part by the breath control mentioned earlier.

Conclusions

The final criterion, as with any musical instrument, must be the sound these two synthesisers make. It's my view - and I've hinted at this in the facilities rundown above - that the DX9 can come a lot closer to the sonic output of its senior partner than most people give it credit for.

To put this into some sort of practical perspective, a number of people have come into my studio to do sessions recently and remarked on the fact that my DX is a 9 and not a 7. Without exception, all of these doubting Thomases have changed their opinion about half an hour into recording.

Not so long ago I did some music for a television programme using the DX9 almost exclusively, and a couple of members of the studio staff commented - on hearing the final tape - that I must have been using a PPG, an Emulator and a DX7. Need I say more?

So, if you've budgeted for a DX7 at £1300, I suggest you give the smaller DX9 serious consideration. If you're still not convinced by my remarks concerning the two keyboards' relative facilities and sonic capabilities, remember that the difference in price between the two could buy you a second MIDI synthesiser (I bought a JX3P with the money I saved), a polyphonic sequencer, or a drum machine. Alternatively, you might find you don't have to part-ex your Juno 60 (or whatever) in order to get the FM synthesiser of your dreams.

Naturally I don't expect you to rush out and buy a DX9 simply on the strength of my own experiences, but I do think you should give it a fair hearing. Don't get me wrong, the DX7 is an incredible instrument and worth twice its normal selling price, but then again, and contrary to what a lot of the music press have said, so is the DX9.

Readers may be interested to know that a cassette recording of some of the best DX9 sounds is now available free from Yamaha DX stockists or from the importers, Kemble Yamaha. Standard DX9 voices are used throughout the ten-minute sampler, which was recorded without the use of multitracking techniques and with a bare minimum of studio effects.

The reverse side of the cassette (called 'Playing with Reality') contains the voice data for loading the demonstrated sounds direct into a DX9 (once this has been purchased by a suitably impressed listener), and interested readers who live a long way from their nearest dealer should contact Martin Tennant at Kemble Yamaha, (Contact Details).

Meanwhile, if you've already got a DX9 and fancy the chance to win a four-track cassette machine simply by spending a little time programming it, you'll no doubt want to enter a competition that's being organised by the DX Owners' Club in conjunction with Kemble Yamaha.

The competition's aim is to find 20 new voices for the DX9, and the programmers of these voices will each receive a £25.00 cash prize, while the sound that's judged as being best of all will earn its creator a free Yamaha MT44 four-track cassette machine. Following the competition, the 20 new voices will be released on cassette, and the only criterion you must fulfil to be able to enter the competition is that you must be a member of the aforesaid club.

Full details, rules, and an entry form are available from Tony Wride of the DX Owners' Club at (Contact Details).