The DX7 has become both one of the best-selling synthesizers of all time and a truly 'classic' instrument. So how do you improve on it? Jay Chapman reports on Yamaha's long awaited attempt...

Imagine the situation. The DX7 Production Line gently rolls to a halt for the last time. You have sold 180,000 or so examples of an instrument which has been top of the league in its price range for years, which is seen on Top Of The Pops each week, which is heard on almost every record released, and which 180,000 pro, semi-pro and amateur musicians have each happily laid out well over a thousand pounds on all around the world.

This amazing phenomenon introduced FM synthesis to the world at large not with a wimper but with a bang. Not 6 or 8-note polyphony, but 16!! A good touch-sensitive (and aftertouch-sensitive) keyboard. A truly amazing sound production device at a sensible price. Really, really good news. So, what do you do to top that?

YAMAHA'S SOLUTION

In a nutshell, the DX7IID is exactly what its name suggests: it is a Mark II DX7 - a second edition, a second version, an update, an upgrade, a refinement... it is not a new instrument in the sense that the word 'new' implies completely different. Like that other second coming, it has been long awaited, and if the presentation and stage management of both events is not carefully handled, you may be disappointed. What you must do, dear reader, is try and elbow your preconceptions out of the window and examine, in an objective manner, what the DX7IID actually offers you.

Given that the DX7 itself is well known and that comprehensive reviews of it have appeared in the past, this review concentrates mainly on what is new, why it is there, and what it does for you!

MARKET RESEARCH

The first thing to be done, whether by Yamaha or by current DX7 owners, is to evaluate the old before you consider replacing it. The DX7 is very good, but in no way is it perfect. However, the technology that went into the DX7 still has enormous potential, not to mention the fact that Yamaha have spent a lot of money on research and development which they don't wish to throw down the drain.

One question that Yamaha will have asked themselves is 'does the customer want (or need) more synthesis power?' The answer they have come up with, as you will see below, is apparently 'no' in terms of the complexity provided to create a single timbre, although the refinements that apply in this area are quite stunning. The DX7IID is bi-timbral, however, (which has a bearing on the 'complexity' issue) and sports a host of extra features which greatly enhance its capabilities, particularly as a 'live performance' instrument.

Yamaha have obviously decided to build on the sturdy (and stylish) foundation work already done. The DX7's imperfections have been dealt with and great care has been taken to develop the full potential of the FM technology.

So, keep the best... and redesign the rest. Listen to the current DX7 owners. Carefully compile your customers' wish list and add the features they want. Rework interesting ideas which didn't quite come off. Improve resources where the result is worthwhile and the cost is not unreasonable. Use hindsight to tell you what new directions to head in.

One thought that must have been uppermost in the minds of the DX7IID's designers was the fact that 180,000 people have made some effort to come to terms with the world of Algorithms and Operators. 180,000 people have sweated and strained to create their own voice libraries - well 18,000 at least ...surely? 180,000 people are already converts to the DX7 world and maybe persuaded to upgrade to the DX7 Mark II, so there must be compatibility - there are thousands and thousands of voices out there which will be available to Mark II owners, a good selling point. Don't trample all over a legend, instead use the reputation, experience and technical skills already built up as a launching pad. The DX7 is dead, long live the DX7IID!

Yamaha, if you haven't already noticed, have quietly killed off their KX Master Keyboard range and you will discover that the DX7IID is designed to take over the KX role. Yamaha, and other manufacturers, have found that most punters will not pay umpteen hundreds of pounds for a Master Keyboard which produces no sound. Most of the facilities required can obviously be built into any MIDI-equipped keyboard, and the DX7IID looks good in this context. The actual keyboard is not of the same length or construction as the KX88 though, that would have put the price up considerably.

OPEN THE BOX

I open the box marked 'DX7IID' and nearly drown in a veritable sea of Quavers. I eat half of them before I realise that they were part of the packaging material... Yes, the product comes well packed in a stout box which you can substitute for a flightcase - for a while at least. Inside the box was (eventually) revealed the beast itself, along with a music rack, ADP-1 cartridge adaptor (costing £22 extra), 'Voice & Performance List' and a telephone directory...

Sorry, that last one should have read 'Owner's Manual'; it just happens to look about the size and thickness of a telephone directory. To be fair, it is actually an 'Owner's Manual', a 'Manuel d'Utilisation' and a 'Bedienungsanleitung' all rolled into one. If your French and German aren't up to scratch you can always stick to the first third of the manual. On the other hand, if you fancy a quick 'mise sous tension' or 'Ausschalten der Speichersicherung' then put on your EEC sweatshirt and go for it! The manual covers both the DX7IIFD and DX7IID, so if you buy the one without the floppy disk drive you can read about what you're missing!

The manual is very comprehensive in describing the facilities available on the DX7IID/FD instruments and discusses carefully how to access and make use of them. It is full of diagrams and drawings of actual displays so that you don't get lost during experiments. FM is discussed at appropriate points in the manual (as you learn how to edit voices, for example) and there are about 18 pages of discussion devoted to FM topics and hints and tips. This is a good start, but if you want more Yamaha will sell you their book on the subject, written by that famous double act: Chowning & Bristow. It's good to see such a high quality manual provided: somebody at Yamaha needs congratulating!

LET'S GET PHYSICAL

Black plastic, 5 octaves, suitably sexy... you want more?!

Two things stand out as soon as you look at a DX7IID. Firstly, the buttons stand out - literally! No more funny membrane things: these are real buttons that you can feel in the dark, that have a positive action and a nice click. So, there is your first piece of evidence that Yamaha have been listening to DX7 owners! The second doesn't literally stand out but is one of the major improvements over the DX7 - the display.

Now we are getting serious! The display on the DX7IID is a two line, 40 characters per line, illuminated LCD type. This represents two important improvements. Firstly, you can read the display in the dark and from any (reasonable) angle. Secondly, because the display is much larger than on the DX7, far more information is available at one glance. This means that parameters can be shown in meaningful groups - which eases editing no end. For example, if you want to edit an Envelope Generator then all eight parameters appear on the display at once. Similarly, if you want to tamper with the frequency of an Operator then all three parameters (Mode, Coarse and Fine) can be accessed and viewed at the same time. It's hardly a computer terminal screen, but it really does make a big difference.

By the way there are two 2-digit, 7-segment red LED displays as well which tell you what voices you currently have selected.

BI-TIMBRAL

The original DX7's 16-note polyphony capability was rather nice but how many times would you have preferred two lots of 8-note polyphony instead? Perhaps you would have fancied a DX5 instead of the DX7, or maybe a TX7 as well as the DX7. Well, with the DX7IID you get two 8-note 'instruments' without paying a penny extra! By way of comparison, my Oberheim Matrix-6R can only manage one 'instrument' of 6 notes or one of 4 notes coupled with another of 2 notes (it does have some other good points, however!).

Not only do you get two 'instruments', which can be arranged in Dual (ie. layered) or Split configurations, but they can be output in stereo via separate jack outputs. Panning between these outputs can be controlled from various sources, such as an LFO or a dedicated Envelope Generator. If you get the chance listen to Cartridge Voice 32, entitled 'KoikeCycle', which is Dave Bristow's imitation of a Japanese colleague's motorcycle blasting across the soundfield!

Returning briefly to the 'complexity provided to create a single timbre' issue, it doesn't take too much thought to realise that you can now use dual mode to create an 8-note polyphonic, 16 Operator, 1024 Algorithm FM synthesizer - which should keep the Voice Editors amongst you happy for a week or two!

'FAT' SOUNDS

It should go without saying that you can detune the two 'instruments' against each other, which offers the possibility of those 'fat' sounds that everybody likes so much. Yamaha have gone one step further, however, by allowing the allocation of four sets of sound generators to a voice (giving 4-note polyphony in 'Single' and two times 2-note polyphony in 'Split' modes) all of which can be detuned. A good example of this effect in action is Internal Voice 6 'Superbass'.

Another new feature that contributes to the sound, this time in terms of the 'warmth' and 'ensemble' effects, is the provision of one LFO per voice (ie. 16 LFOs, one for each note of the polyphony available) rather than one for the whole lot. This means that each LFO can start its cycle independently whenever a note is played. This makes a difference when simulating a violin section, for example.

NOISE

Or rather the lack of it - unless you programme it into a voice on purpose, of course! One of the major criticisms of the DX7 was the noise generated by the FM circuitry; people in expensive recording studios just don't like noise being introduced at all! On 'quiet' voices the noise was quite distracting and I wrote to Yamaha asking them to do something about it; evidently they got my message (and presumably got the same message from many other people too) because the DX7IID is very quiet indeed.

If you want to test this out choose Cartridge Voice 64 'Init Voice' and listen carefully - I don't think you'll have any complaints. If the noise at the start and end of notes bothers you, set Rate 1 and Rate 4 of Operator 1 to about 75; it's the square edge of the 'Init Voice' Envelope that is causing the noise (as it should) and not any problem with the circuitry.

Okay, I'll come clean - I haven't taken any measurements to prove the following, but Yamaha tell me that the FM system on the DX7IID has been changed (hence the lack of noise), giving improvements in both frequency response and dynamic range. The improvement corresponds to something like the effect of increasing, by 2 bits, the bit resolution employed in the FM system (which should make a considerable difference). I'm afraid I haven't had time to do side by side comparisons of the same voice in a DX7 and DX7IID because of the short time in between my getting my hands on a DX7IID and the magazine's copy deadline.

Subjectively, the sounds are very, very good. In fact, when Dave Bristow showed the DX7IID off at the press launch, one just had to be suitably amazed. It always worries me a little bit, however, that I can't play anywhere near as well as Mr B. and he isn't supplied as an optional extra. Ah well, you can't win 'em all!

VOICE COMPATIBILITY

Both Internal and Cartridge memories are available; if you buy a DX7IIFD you will have a 3.5" floppy disk-drive as well.

The most obvious storage requirement is for voice-related data but the DX7IID has a few other bits of data to cope with as well, as we shall see. Note that the old DX7 cartridges will not plug directly into the DX7IID but Yamaha do make an add-on adaptor, the ADP-1, which costs £22. Since the DX7 parameters form a subset of those available on the DX7IID, all your old DX7 voices can be used on the new synthesizer. If you load them into a RAM cartridge or transmit them via MIDI to the DX7IID then you can edit in all the new features where appropriate.

The DX7IID uses a new RAM cartridge, the RAM4, which is not compatible with the DX7 RAM1. However, it is possible to read ROM cartridges meant for the DX1, DX5 or DX7 using the ADP-1, as well as reading the RAM1 cartridge they use, but you cannot write to RAM1 from the DX7IID.

Not all of the new machine's pre-programmed voices are going to suit you, of course, but many of them will prove useful and some of them will absolutely delight you! The ROM cartridge that comes with the DX7IID contains a full set of copies of the internal voices, so you need have no qualms about creating new voices and overwriting the set that comes initially loaded in the Internal voice store.

There are the usual DX-type sounds plus some Oberheim-like analogue sounds to show that the DX7IID is quite capable of such things. The voices have been programmed by Dave Bristow and Gary Leuenburger (Dave's American counterpart) who are probably the top two people in the world at this sort of thing. There is no point in me trying to describe the sounds or assign them some sort of quality rating when you can get on down to your local Yamaha dealer and form your own opinions. Persuade him to play the DX7IID through a decent amp/speaker set-up in stereo with reverb to taste...

As you try the sounds you will begin to realise what an important role the various performance-related parameters and controllers play in promoting the sheer playability and usefulness of a sound (more detail on the controllers below). The Performance Memory aspects of the DX7 have been greatly improved upon: you can now store performance parameter details with each voice in a similar manner to the TX7. This is no great surprise since Yamaha had obviously noted their earlier omission - don't forget that the TX7 had performance memories both for its own voices and for the DX7 that was assumed to be driving it.

Since we have a bi-timbral instrument here, there is further performance information to be considered. Which two voices get selected together? Split or Dual? Split Point? What about panning? Detuning? Overall Volume and Balance? ...I could go on.

INTERNAL: In fact, there are 32 Performance memories of the type partially described in the last paragraph in order to cope with the 64 voice (and 'local' performance) Internal data memories provided onboard the DX7IID.

CARTRIDGE: The ROM and RAM4 cartridges can be formatted to provide storage for four different types of data: voice and performance; system set-up; fractional scaling; and micro tuning. I wont get time to talk about the last three in this review but no doubt I will in some future article. The ROM cartridges hold four Banks of data, but RAM4 can only hold one Bank. The RAM4 is relatively cheap at £55 and probably worth having if you get well into editing (unless you have a DX7IIFD with built-in disk drive, of course).

So, taking both Internal and Cartridge memory into account (ie. assuming that you have a cartridge plugged in), you would have a minimum of 128 Voice memories and 64 Performance memories available to you via a few button presses. Using the ROM cartridge supplied with the DX7IID, and assuming you had filled the Internal memory with your own voices, the numbers increase to 192 Voice and 96 Performance memories. If Yamaha, or third party voice programmers, start producing Voice ROMs you could get up to 320 Voice and 160 Performance memories. Not bad,eh?

The DX7IIFD's floppy disk will store even more data, of course, but it will take you more time to press the right buttons to load data into internal memory. Since I had access to a DX7IID and not a DX7IIFD, I will mainly ignore the disk drive possibilities in this review.

PERFORMANCE CONTROLS

Both the quantity and the applicability of performance controls has been drastically improved on the DX7IID. There are Pitch and Modulation Wheels, as you would expect (my Pitch Wheel wouldn't bend down from the original pitch: I rang Yamaha who immediately tested the DX7II's they had on hand and none of them exhibited this problem so I assume I just got unlucky; these things happen!).

You also expect Aftertouch, Breath Control and the possibility of using a Sustain Foot Switch and again you won't be disappointed, they're all there.

Yamaha haven't stopped there, however. There are sockets for two Foot Controllers (ie. continuously variable pedals) and a second Foot Switch (ie. on/off like the one for Sustain). The second Foot Switch can be used for a variety of functions including 'key hold', which gives a 'sostenuto' effect where the notes you are holding when you depress the switch are sustained but any new notes you play are not. So far the controller set-up described is exactly the same as that on the Yamaha KX88 and it would therefore appear that we do have Master Keyboard Controller potential.

There are, in fact, a total of 9 (yes, nine) devices for performance control available. It is possible for certain controllers to substitute for, or act in parallel with, certain others: if you have Continuous Slider 1 (CS1 - see below) set to perform some control function, and realise you haven't got a spare left hand to move the slider, you can assign Foot Controller 1 to act as CS1, for example.

Unlike the KX88 (which comes with one Foot Controller, one Foot Switch and one Breath Controller) the DX7IID has no external controllers supplied; you have to purchase them as optional extras. Since I am of the opinion that a Sustain Foot Switch is absolutely essential for a keyboard instrument, I would have liked to have seen at least this provided as part of the package. It is fair to say that you won't be able to unleash the full potential of the DX7IID without at least one Foot Controller and one Foot Switch. How about supplying these two pedals in a promotional package at a special discount price for anyone purchasing a DX7IID - are you listening Yamaha UK?

CONTINUOUS SLIDERS

Two more 'controllers' are supplied on the DX7IID itself in the form of two sliders (CS1 and CS2) which are similar to, and positioned next to, the Volume slider. Generally, you can use these as well as, or instead of, the other forms of continuously variable control available.

Now all the performance controller stuff is very tasty and very useful. Anyone who has tried using Aftertouch to add controlled vibrato or open up the 'filtering' of a voice will know what a difference a good controller can make. Whilst the controllers have an important contribution to make, they are not alone in doing their job: the range of things that can be controlled matters too! The DX7 had various capabilities in this area but the DX7IID has moved up into a different league altogether...

I'll warn you straight away that there are simply too many possibilities to be gone into in detail in a review - this article isn't supposed to be a copy of the manual, after all! Also, some of the ramifications of what I'm presenting an overview of will not become apparent until you have had quite some experience of the DX7IID. This is definitely an instrument that you will 'grow into' over a period to be measured in months rather than days.

There is control of the same parameters as before, such as Pitch and Amplitude Modulation, and Envelope Bias - again, on an Operator by Operator basis. However, far more pitch control is available than before: it is now possible to add pitch bends via Aftertouch, for example, which is a wow for jazzy guitar solos. If you get the chance try Internal Voice 3 'PickGuitar'; the combination of pitch bend via Aftertouch and a velocity-sensitive keyboard will have you in raptures! Oh yes, it's also possible to arrange that only the highest or lowest note of a chord is pitch bent and to avoid sustained notes being pitch bent - very useful. And, as we will see in a moment, any of the parameters of the Pitch Envelope Generator can be controlled during live performance.

CS-CONTROLLABLE PARAMETERS

You can use CS1 and CS2 sliders to control almost anything - in fact several things at the same time, in live performance. Have a look at the list of controllable parameters shown in Figure 1. Admittedly you will need to understand the effect of altering such parameters to really get into this facility. For example, altering a Modulating Operator's Output Level affects timbre rather differently from altering that of a Carrier Operator. Experimentation, and analysis of the pre-programmed voices, will pay dividends here.

The Continuous Slider implementation shows evidence of the flexibility that Yamaha have built into the DX7IID. There is even more to come...

MIDI

Yes, the magic word had to crop up eventually!

The DX7 had a reasonable MIDI implementation. It included two major blunders, however, both on the transmission side. Firstly, you were restricted to transmitting on MIDI Channel 1 and, secondly, there was no implementation of the 'Local Control' feature which allows the control side of the synthesizer to be isolated from the sound production facilities. Local Control, whether implemented implicitly or explicitly, is an absolute must for any keyboard instrument that aspires to Master Control Keyboard status - and with the original DX7, Yamaha blew it! To be fair, you have to remember that the KX88 coupled to a TX7/TX816 were seen as dealing with this area. The role of the DX7 in the MIDI network has been most definitely updated with the DX7IID.

The obvious requirements for Master Control Keyboard have now been met. Local Control can be turned on and off, control messages from the various built-in and external performance controllers can be transmitted, program change messages can be sent, and so on. However, it does not appear to be possible to transmit on separate channels in Split keyboard mode, which seems a little short-sighted of Yamaha.

The DX7IID's implementation of the other side of the MIDI coin, reception, is also very good. Parameter changes (via System Exclusive messages) are dealt with quite happily which means that computer (or sequencer) control, or control from some other Master Keyboard, should pose no problems.

INDIRECTION

Yamaha have introduced another layer of sophistication into their MIDI implementation that would be perhaps known as 'indirection' in the computer world. In many, if not most cases, you can not only specify that a particular parameter is to be controlled via MIDI, but you can also specify which MIDI controller message will be used, rather than settling for a default controller message which may not be interpreted correctly at the receiving device. This applies both to transmission and reception by the way, and greatly increases the flexibility of your MIDI control.

Another 'indirection' feature is that you can specify what MIDI control message will drive the sliders, CS1 and CS2, which themselves can each be driving several parameters in parallel. It is also possible to have the act of selecting a new program number on the DX7IID actually transmit the selection of a different program number over MIDI, which is useful when you haven't organised voices that are to be used together on different instruments into the same store number on each instrument.

There is plenty more to talk about on the DX7IID but I have, unfortunately, run out of time and space. What I have left out - such as MicroTuning and Fractional Scaling - are things that the average user will appreciate (when he realises they are being used) but will not be likely to actually play with for some time after buying a DX7IID.

To be fair to Yamaha and to you, the readers, I have to point out that this review has been written in great haste to ensure that SOS brings the news about the DX7IID to you as soon as possible. I have only had a few days to familiarise myself with the instrument, which means that there is a good chance that I have not fully understood and/or appreciated all features, good and bad, of this complex keyboard instrument. If I have omitted anything important, I apologise in advance.

CONCLUSION

At first glance it is tempting to be disappointed with the DX7IID.

Why? Well, probably because we have very high expectations based on what the original DX7 did for us. Our problem, and it is a problem that Yamaha must be a little frightened of, is that whilst we expect 'a lot' for our money, we have never really formulated what 'a lot' means in this context. We probably want lots more synthesizer power, lots more memories, lots more control, lots more MIDI, more quantity, more quality and, of course, a low price! We probably half expect speech control and a laser show to be built in as well!

So what have we actually got for the same price, more or less, as the original DX7? Well, if you look at it honestly, we definitely have got 'a lot'.

We haven't got a new technology (which would have looked sexier on the advertising blurb) but have got a 'matured' version of the current technology. The DX7IID is more controllable, more flexible, more general purpose, better fitted to being a Master Controller Keyboard; it sounds good, is easier to use - particularly in live performance - and it is easier to edit voices (though understanding FM hasn't got any easier, of course).

Be warned, however: you will have to work even harder (than with the DX7) to realise the full potential of this instrument - it is very complex and it is very sophisticated. In a sense, this is the price we have to pay for wanting so much in the first place.

Who will buy it?

Anybody who hasn't got a synthesizer and is moving into this price range will be tempted. Of course, there are other contenders for your money (sampling keyboards, for example), but if you want everything that FM, complexity and sophistication offers, then the DX7IID fits the bill.

If you already have a DX7 then it depends how thick your wallet is. I don't think that you will get a lot for your DX7 in part-exchange now that the Mark II version is around - but I could easily be wrong!

If you were considering a Master Keyboard-based set-up, then maybe replacing a DX7 with a DX7IID is a reasonable answer. If, like me, you already have a Master Keyboard that you are happy with, then the obvious thing to do is buy the Expander version of the DX7IID. Or rather it would be the obvious thing to do but, unfortunately, no such animal exists at the moment.

However, having seen the TX7 follow the DX7, what's the betting that a TX7IID or TX7IIFD will follow the DX7IID and DX7IIFD? The only problem with this quite reasonable piece of speculation is when will it see the light of day? We will have to wait and see...

A word of thanks is due to Jim Corbett of Yamaha who has been extremely patient and very helpful in responding to my barrage of questions over the phone while I have been preparing this review. Yes, I know it's his job but you get to appreciate people who know what they're talking about in this business!

MRP of the DX7IID is £1699 inc VAT. (The DX7IIFD with built-in disk drive retails at £1899 inc VAT.)

Further details available from Yamaha-Kemble UK Ltd, (Contact Details)