Way back in 1983 (is it really only that long ago?) Yamaha rocked the music industry by producing a world-beating synthesizer - the DX7. Since then various forms of the basic FM concept have appeared on a number of Yamaha keyboards but they have all employed either 6 or 4, sine wave generating, operator configurations. The 6-operator synths (DX7) are capable of producing some truly amazing sounds by the combination of the six sine waves, whilst the 4-operator synths (DX100/27/ 21) always lack a little something.

Recently, however, the 4-operator brigade struck back with the popular TX81Z expander, which proved that by giving the operators a special feature you could create some very good sounds. That special feature is the ability to select seven additional operator waveforms other than the usual sine wave, to generate richer, more complex sounds like those of the 6-operator FM synths. The TX81Z has other features which have helped its popularity - in particular, the fact that it is multitimbral (ie. it can produce up to eight different instrument sounds simultaneously) and offers a good MIDI spec. To a lot of people the only drawback with the TX81Z is the lack of a keyboard. But in true Yamaha style the TX81Z has been given a keyboard and called the DX11!! Actually, it has a few other 'extras' as well but you'll have to read the article to find out more.

THE HARD STUFF

The DX11 has a five octave, C-to-C, velocity and pressure (aftertouch) sensitive keyboard, which feels just like a DX7, but the instrument is slightly shorter due to the repositioning of the Pitch and Modulation wheels on the front panel. Some of you may not like this set-up if you have always had the wheels at the side of the keyboard, but I found that it only took a short while to get used to. On the left end cheek of the keyboard is the often unused Breath Controller socket. Apart from the additional cost of buying the Breath Controller, I have often wondered why more people do not use them since it provides a good way of applying expression to your playing without having to take a hand away from the keyboard.

The back panel contains a host of sockets including: Phones, two Outputs (yes, it is stereo), Volume Control and Foot Control (both of which require an optional FC7 or FC9 pedal), Footswitch, MIDI In, Out, Thru, and Cassette.

The front panel follows the normal DX style of having Volume and Data Entry sliders and buttons to the left of the LCD, whilst the Bank and Voice selectors are to the right. In keeping with most other Yamaha gear, the 32-character LCD is backlit and all buttons are of the raised, positive click variety. It is good to see the RAM4 cartridge slot included on the DX11, since it does provide one of the quickest ways of accessing additional voices, particularly when playing live.

GREETINGS

After switching on, the LCD lights up and displays its 'How are you?' greeting for a few seconds before adopting whatever voice was set at power-off. A nice little feature is that you can adjust the 'greeting' to say whatever you like within the limit of 16 characters. So, as an additional security measure, you could set your name and postcode to appear each time the machine is switched on, since there is a particular routine required to adjust the message and unless a would-be crook has access to a manual, or reads how to do it in an unthinking magazine, he will not be able to erase the message!

As one does when one gets something new, I immediately wanted to hear what the DX11 could do, so I selected Performance Mode and started 'tinkling the plastic'! A run-through of the 32 Performance memories left me somewhat stunned, since I never thought a 4-operator synth could produce the sounds that I was hearing. Admittedly some of the sounds are a bit 'naff' and some are very typical FM, but in amongst the 32 are some real stunners. It is obvious that Yamaha have made full use of the multitimbral capabilities of the DX11, as well as the preset waveforms, since what I heard almost made me think I was playing a DX7 one minute then a Roland analogue synth the next.

My particular favourites were the 'solo' sounds which made use of a number of different instruments, or detuned multiples of the same instrument, to produce some very powerful sounds. The bass sounds, particularly 'Tight Bass', are about as raunchy as you could want and my other favourite, 'Orchestra', is a very close likeness to the orchestral stab made famous by Fairlight. The 'polyphonic' sounds are also very reasonable but the best results seem to be obtained when a voice is doubled, which limits the polyphony to four notes instead of the maximum eight.

IMPROVED MEMORY

There are seven internal memory banks in the DX11 comprising four banks of 32 preset (unchangeable) voices, one bank of 32 programmable voices, one bank of 32 Performance memories, and a Program Change table. The four preset banks provide a fairly wide variety of sounds ranging from synths to percussion, and most of the classic FM sounds are to be found as well as some uncharacteristic ones. The programmable voice bank comes with a duplicate selection from the preset banks and it is here that you can store up to 32 of your own creations/edits. However, it is the Performance memories that make the DX11 more than just another FM synth. The following brief list gives you some idea of what each of the 32 Performance memories can contain for each of up to eight 'instruments':

Assign Mode (normal/alternate)
Max. Notes (0-8)
Voice Number (101-D32)
Receive Channel (1-16, Omni)
Limit Low (C-2-G8)
Limit High (C-2-G8)
Instrument Detune (-7 — +7)
Note Shift (-24 — +24)
Volume (0-99)
Output Assign (off, 1, 2, 1+2)
LFO Select (off, 1, 2, vib)
Micro Tune Select (off/on)
Effect Select (off, Delay, Pan, Chord)
Performance Name

In addition to the onboard storage, a RAM4 cartridge (or equivalent) can hold one bank of 32 voices, one bank of 32 Performance memories, one Program Change table, and a host of other system data including microtuning and effects data. Yamaha mention that future data cartridges may be able to contain up to 16 such 'sets'. There is also a cassette interface for low-cost storage of data.

VOICE STRUCTURE

There has been so much published on FM that I won't go into depths about how FM voices are created but simply say that the DX11 is a 4-operator, 8-algorithm machine. Like the TX81Z it gains over previous 4-operator synths by having available eight different waveform shapes which can produce a wide variety of harmonics. Some of the waveshapes are fairly close to what you might get from an analogue synth and on earlier DX models you had to use a mixture of at least two operators to achieve such waveforms.

Sounds are normally created by combining the waveforms of the operators using Frequency Modulation techniques (modulating the output of one operator by the output of another). The overall level at which a 'modulator' (the modulating operator/oscillator) affects the 'carrier' (the operator that's being modulated) gives the change in tone, as does the frequency difference between the two operators. Tonal adjustment throughout the playing of a note can be achieved in a number of ways including using an envelope generator or by one of the numerous controllers.

The DX11 has fairly simple envelope generators which, although they are akin to an analogue synth's ADSR, lack the total flexibility of the DX7. This means that although the DX11 can produce some of the classic DX7 sounds, it lacks that little bit of finesse on the envelope front.

Like most modern synths, the programming of a DX11 voice involves a fairly lengthy button-pushing process to change the numerous parameters, but the LCD helps you keep track of what's going on and the manual gives a reasonable guide. It would have been nice to see some examples of how to programme different sounds into the DX11, since I feel that a complete newcomer will find himself limited to using the presets through lack of information. Mind you, reading Martin Russ's 'Practically FM' articles each month (see p58) should help fill the gap in information left by Yamaha.

Still apparent on the DX11 is the 'quantisation noise', a hiss which is very noticeable on low notes and does detract from the otherwise good sound quality produced as you move higher up the register. It's a shame Yamaha didn't do something about this since I am sure several people will compare the DX11 with, say, the new Kawai K1 and go for the 'cleaner' sound.

The DX11 has two 'play modes'. Single and Performance. In Single mode you are limited (surprise, surprise) to just one voice at a time... well almost. One of the beauties of FM is that it is possible to have two different sounds coming from within a 4-operator structure, and several examples of this are apparent within the preset banks. For example, you can achieve an acceptable 'BrassBell' sound using two operators for the brass sound and two for the bell and still be able to play with 8-note polyphony. It is using this technique that you can achieve not just a piano sound but also a string sound brought in by one of the controllers, such as aftertouch (pressure). This is a distinct advantage over other forms of synthesis where invariably you are limited to just the one sound unless you layer. Whilst quite reasonable results can be obtained using Single mode, the DX11 really shows its strength in Performance mode.

In Performance mode you can have up to eight independent sounds playing at any one time, but with one restriction. You are limited to playing a maximum of eight notes, so if you do select eight different sounds the DX11 suddenly becomes a monophonic synth. However, each voice can be freely assigned a number of notes, programmed to occupy a defined area (zone) of the keyboard, assigned its own MIDI channel, and numerous other things listed above. I should point out that the facility to define the number of notes to be played becomes very useful when using the DX11 as a split keyboard, since you could have a 6-note polyphonic piano sound within the lower three octaves and a 1-note dual voice lead sound within the upper two octaves. Conversely, you could have four 'splits' each with 2-note polyphony, or assign two voices to the same keyboard range to produce layered sounds - the combinations are almost endless. The factory-set Performance memories give various examples of the many possibilities.

QUICK EDIT

Each of the voices has 69 parameters that can be adjusted to not only create the basic sound but also set up how the various controllers are going to affect the voice. This is an extremely useful feature since it allows you to use the expressive capabilities of the DX11 to the full. Only the Breath Controller or Aftertouch can be used on Pitch Bias, which is the ability to 'bend' notes, and I found this extremely useful when playing solos where you sometimes don't have a hand spare to use the Pitch Bend wheel.

One interesting parameter is Reverb Rate. This controls, in fact, a pseudo-reverb effect created by slowing down the EG release rates after a certain point. It's a clever trick which actually works very well. Another feature worth mentioning is the Pitch Envelope Generator, since the TX81Z does not have this facility. The Pitch EG, as it is referred to, allows you to add the sometimes natural, and not so natural, initial shift in pitch which is a characteristic feature of many acoustic instruments.

Yamaha have finally responded to the cries from the wilderness and included a 'Quick Edit' facility on the DX11, which allows you to do just that. There are four areas of the sound that can be edited in this mode: Attack and Decay rates, Sustain/Release, Volume, and Brightness. Using Quick Edit allowed me to adjust several of the presets, particularly the pianos, to my own taste without delving into the complex depths of FM programming.

Like the TX81Z, the DX11 has some onboard 'effects' - four Delay settings, four Pan settings (it's stereo, remember), and four Chord settings. Within each of the Delay options you can adjust Delay Time, Pitch Shift, Feedback, and Effect Level. The Delay Time is variable between 0.01 and 1.28 seconds, the Pitch Shift is variable between -24 and +24 semitones, while Feedback affects how the velocity of each echo is decreased and indirectly determines the number of echo repeats. The Effect Level determines the velocity of the first echo and also indirectly determines the number of echoes. Using a combination of all of these parameters it is possible to achieve some good results. For instance, the 'Glocken' sound uses Pitch Shift and Delay to create echoed notes that rise in perfect 4ths. You can, of course, set up four different delay effects of your choice and then select any one of them within a particular Performance memory.

There are three adjustable parameters within each of the Pan effects which basically determine the balance of audio outputs 1 and 2. To use the effect you need to have two instruments playing, since one has to be initially assigned to Output 1 and the other to Output 2. You can choose between LFO, Velocity, or Note to determine the source of the stereo movement and I found that some very pleasant results could be achieved using the LFO to pan an electric piano sound back and forth.

The Chord effect allows you to produce up to four simultaneous notes when a single note is pressed and is very effective if your playing skills don't stretch to some of the more obscure chords! Microtuning is also available in the form of 13 microtonal scales (11 preset, 2 programmable) for those of you who understand the use of anything other than the 'equal temperament' scale found on a piano, but I'm afraid I plead total ignorance on the matter.

I mentioned at the start that I was surprised at how rich some of the DX11 preset sounds were, and although part of this due to the use of its built-in effects, another major factor is the exploitation of the LFO and Detune capabilities. Careful use of different LFO settings and slight detuning between voices in a Performance really does thicken up a sound. It appears that you can have eight independent LFO rates for use on Pitch Modulation within a Performance memory, but only two independent rates on Amplitude. Thus, on a solo sound using eight different voices all slightly detuned with different LFO rates on Pitch Modulation, you can end up with a sound as thick as tar! You do, however, need to have set up your LFO responses when the voices were programmed, so a fair bit of forward planning is required. Again, a comprehensive step-by-step example of how to do this would have been a useful addition to the operating manual, as I feel sure a lot of people will never realise the true capabilities of the DX11.

MIDI

The MIDI capabilities of the DX11 are very impressive, offering all the usual facilities of variable Transmit and Receive channels, Bulk Dump, Local on/off, plus several other useful features. As you can have up to eight different voices playing at a time in a Performance, it is possible to select which MIDI channel these voices will receive on so that you could, for instance, use the DX11 with a sequencer playing a 2-note sequence and leaving you with up to 6-note polyphony to be played manually.

The Program Change table lets you set the DX11 to respond as you want to incoming MIDI Program Change data. For each Program Change number that the DX11 receives, you can decide exactly what voice or Performance memory is selected. It is also possible to send a Program Change number from the DX11 without having to change the current voice that you are playing, which I found very handy when using the DX11 with an expander.

CONCLUSIONS

I was impressed with the DX11 and suspect that it may just join the ranks of the DX7 in the popularity stakes, particularly if it can compete with the competition from the Kawai K1. As it comes, I was a bit disappointed by several of the Performance memories and preset sounds, which I felt did not give a true view of what the instrument was capable of. I did like the addition of the Quick Edit facility and the overall scope available on the controller front to put a great deal of expression into a voice. I, however, have a fairly good understanding of the workings of FM and I suspect that newcomers to FM will be left in the dark because of the disappointing operating manual. Unless manufacturers increase people's understanding of how to programme an instrument then we'll continue to have synths returned to dealers with very few 'homebrews' onboard. By the simple addition of a comprehensive 'How To Programme Sounds' booklet with the DX11 a new owner would soon see the light and get to grips with the machine. As it is, Martin Russ will have to include some more tips on FM programming of 4-operator synths in his 'Practically FM' series.

Price £679 inc VAT.

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