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Yamaha SY77 (Part 1)

RCM Synthesizer

Article from Sound On Sound, January 1990

The DX7 captured musicians’ imaginations like no other synthesizer before or since. But the legacy of releasing endless variations on the DX theme has turned some musicians away from FM synthesis and into the waiting arms of a new generation of 'sample plus synth' keyboards. Now Yamaha are back with a vengeance, an even more powerful method of synthesis (Real-time Convolution and Modulation), and a spanking new flagship synth. But has the SY77 got what it takes to regain the hi-tech musician's vote? Martin Russ finds out.

With the arrival (at last!) of what must surely be the replacement for the DX7, the SY77 provides a new synthesis method which builds on FM, but which also presents an interesting mix of simplicity and complexity. In this, the first of two articles taking an in-depth look at the SY77, I will describe the major features of this new Yamaha flagship synth.

Next month will see a detailed examination of the synthesis power provided by the SY77's new synthesis method: RCM.


The SY77 is a multitimbral, Advanced FM plus AWM workstation, modestly described on the front panel as a 'music synthesizer'. It has the widest range of potential sound-producing capability I have ever witnessed in an 'affordable' instrument - from fully synthetic to breathtakingly real, all in very high quality stereo (or even quad, for those who remember it!). In the past it has always been necessary for musicians to acquire a mixture of different methods of producing sounds (analogue, sampled, digital, etc), but the SY77 makes that approach virtually redundant. Imagine an instrument which has the potential to sound like a D50 LA synth, an M1 AI synth, a U20 using Resynthesized PCM, a Phase Distortion CZ synth, a K5 Additive synth (with up to 32 harmonics), a Clavinova, a DX7, an Oberheim or Prophet Analogue synth, a CS80 using Ring Modulation to warp sound, and more - plus any mixture of these, and some new ones! It looks like I don't need to wait for a Resynthesizer [see SOS Feb 88] - the SY77 can sound like almost any keyboard, and it is here now!

The SY77 I (and other reviewers) have been using is a prototype version, not a fully finished production line model. Therefore some of the functions I am about to describe may have changed slightly in the final design. The factory sounds will probably be different, so I will not concentrate on those which came with the review instrument. The owner's manual was not available for most of the (short) review period but I unearthed no glaring problems, despite some serious exploration of the SY77's quieter back-alleys. The machine has never crashed, and has performed flawlessly in almost every respect - and this was only a prototype! Production models will be available in late January/early February 1990.


The SY77 is the first digital synthesizer I have ever seen which completely does away with the need for separate storage for layers, splits, velocity splits, zones and the other parameters normally used to define how the basic sounds behave when played from the keyboard (or via MIDI). There is only one type of patch or sound memory - the Voice. A Voice is made up of everything that is needed to define a performance - the sound itself, the effects, panning, micro-tuning, name, output assignment etc. There is no separate storage for any smaller basic unit. Each one of the 128 preset (and 64 user-programmable internal) Voices is constructed from up to four separate structures, called Elements, where each Element is a complete synthesizer in its own right! Alternatively, a Voice could be a set of Drum sounds, but the same idea applies - the Voice is the only thing that you work with when you are just playing the SY77.

Similarly, the interaction between the onboard sequencer and the sounds is made easy by the use of a single multitimbral equivalent of a Voice, called a Multi. A Multi specifies what happens when the SY77 is working as 16 separate synthesizers, and includes all the relevant information about volume, pan, effects and so on, with the basic sounds being just the Voices themselves. There are 16 preset Multis (and 16 user memories), which may be likened to instant pop-up orchestras that you may use for recording songs, and you can save and load additional Multis from the storage devices (more of which later).

The Voice concept removes the potential confusion about whether you are editing a sound or a performance definition - the DX7 MkII can be very difficult to get to grips with because of its many modes for editing and playing voices, performances, pans, duals etc. With the SY77, you just select one of the 128 preset Voices or 64 user Voices, and then play — the splits, layering, tuning, effects etc all form part of the Voice itself. To modify the sound, you just edit the Elements which make up the Voice...

There are only two types of Element, both of which should be familiar to anyone who follows what Yamaha have been selling recently - FM is represented by Advanced FM (AFM), an improved version of the 6-operator FM employed in the DX7 MkII; and playback-only sampling is represented by Advanced Wave Memory 2 (AWM2), a version of which forms the basis of popular units like the EMT10. Together with the interaction of the Elements, this combined technology is called 'RCM' - Real-time Convolution and Modulation synthesis. Next month's SOS covers the details of this method of synthesis, here I am more concerned about using RCM in a performance workstation.


Both the AFM and the AWM2 sections are 16-note polyphonic, giving a total available polyphony of 32 notes. As with Partials in LA synthesis, there is a similar restriction - the more Elements you use in a Voice, the lower the resulting number of notes you can play at any one time. The arrangement of Elements within a Voice can be made in several ways, and is called the Mode. Here are the Modes and the maximum number of simultaneous notes available in each:

1 1 AFM mono (16)
2 2 AFM mono (8)
3 4 AFM mono (4)
4 1 AFM poly (16)
5 2 AFM poly (8)

6 1 AWM poly (16)
7 2 AWM poly (8)
8 4 AWM poly (4)

9 1 AFM + 1 AWM (16)
10 2 AFM + 2 AWM (8)

11 Drum Set (16)

The assignment of Elements is made dynamically, so the SY77 attempts to maximise the polyphony at any one time, but it is obvious that the combined Modes 9 and 10 make the most efficient use of the available resources - since you get twice the polyphony of any other Mode made up from two or more Elements. Not surprisingly, most of the factory supplied sounds tend to use Mode 9. There is more to these Modes than might be apparent at first, and this will be covered in detail next month.


Accessing the Voices necessitates interacting with the instrument itself, so I had better describe what is available. The SY77 is a 17kg (quite heavy), 1046mm x 400mm x 117mm box sturdily made of folded steel and black aluminium extrusion, with plastic end cheeks and disk drive mounting. The angled front panel makes it reminiscent of the Kurzweil 250, and even the old Yamaha CS80. The casing is finished in the latest Yamaha matt black (dark grey?).

The front panel is dominated by the large central display - a blue, backlit LCD with 240x64 dots. A rotary contrast control is hidden away on the back panel (in the original DX7 it was inside, unreachable in normal use!). In stark contrast to the Korg M1, the remainder of the front panel is covered in buttons, sliders, and an alpha dial - all black, of course. Luckily the 32 status LEDs are mostly red/green, and these flash and change colour to give welcome visual feedback on what is happening.

There are two Modulation Wheels: one is in the normal form, whilst the other is a centre-off version whose MIDI Controller number is assignable to any Controller from 0 to 120 (but only the most significant seven bits are used, I think). The sprung Pitch Wheel has the usual centre detent. The 61-note (C1-C6) keyboard is both velocity and aftertouch (channel pressure only) sensitive.

On the left, above the performance wheels, is a 720K capacity (not High Density!) 3.5" floppy disk drive for storing Voices, Multis, Sequences etc. There is no dedicated space for storing spare disks, unlike the Ensoniq VFXSD and the Roland D20. Floppy disk drives are generally not noted for their speed, but making SY77 disk backups can require five or more disk swaps! This suggests that there is less than 200K of free RAM inside the machine - and since this is usually used to store Sequence data, formatting and backing up disks wipes any sequence from memory. (Atari ST, Yamaha C1 or IBM PC compatible owners will be pleased to learn that using a standard 'bit copier' program on these computers will produce perfect backups of SY77 disks with no problems, and with no tedious disk swaps or loss of sequencer memory!)

There are four sources of sounds on the SY77: for rapid access the Internal user memories and two Presets, P1 and P2 (each with 64 Voices split into four banks of 16, A to D) provide storage for 192 on-board Voices. In addition, there are two card slots marked 'Voice' and 'Waveform', which rather gives away their intended use. These accept 256K or 512K RAM or ROM credit cards (but not American Express!). The disk drive provides the fifth source of on-board sounds - although accessing sounds from a disk takes longer than from a card and overwrites the Internal user memory bank, which means that you only ever have a choice of 256 Voices. Waveforms can only be taken from the Waveform card slot, not from a disk (a pity!), but otherwise the two mediums can store similar types of data - you have the choice of low cost disks with slow access, or faster but more expensive cards. As with the DX7II before it, micro-tuning data (and AWM2 waveforms) must be on the same external storage medium as the Voice which uses it - so Card Voices must access Card data, not Internal data, although the Presets are always available. A similar restriction applies to Voices employing those modes which use all four Elements - they can only be stored in Bank D, because of the size of their definition files (over 1K each).

If the DX7 and V50 are anything to go by, you can probably expect the production model SY77s to come with either a ROM card or a floppy disk containing some sounds and/or a demo song or two. (Try as I could, I failed to find the hidden buttons to activate the built-in SY77 demo song, so perhaps there isn't one?!) I suspect that the established third-party sound library companies will concentrate on producing new ROM cards, whilst SY77 owners will utilise the 3.5" disks for distributing their own voices.


The controls are split into sensible sections. The far right has 24 Voice selection switches which are also used for Element control whilst editing - Element on/off, Operator select etc. Sixteen of the buttons are assigned to numbers 1 to 16, four are used to select Banks A to D, and the remaining four are used to select from the Internal user memories, the Card, or the Presets - no multi function colour-coded buttons here!

Over on the far left, below the card slots, are the five operation mode selector buttons (not to be confused with the Mode used to describe the arrangement of Elements): Voice, Multi, Song, Pattern and Utility. The leftmost 'Voice' button selects Voice mode, whereupon its LED illuminates red. The Memory, Bank and numeric buttons will now call up the stored Voices, although not immediately. Having selected a Bank and Memory source (the LEDs flash to show they have been selected), nothing will happen until you press the numeric button - neat, sensible and well thought out. This avoids the problem found on some instruments, where selecting a new Bank instantly changes the sound before you can choose the patch number in that Bank!

Three buttons complete the row of eight on the left-hand side: Edit accesses the editing pages for whichever mode you are in; Copy lets you copy either an Operator, Envelope, Filter or Element, depending on the current editing page; and Effect Bypass lets you temporarily remove on-board signal processing and hear the original sound.

Continuing the theme of careful planning and forethought, the SY77 provides lots of ways of doing things - especially editing values and entering numbers. Instead of pressing one of the 16 numeric buttons, you can use the keypad instead. Typing a two-digit number and pressing the Enter button lets you use the MIDI program number (up to 99, anyway) to select sounds, and three-digit numbers can cover the whole range of available MIDI Program Changes - typing numbers above 128 just produces 128. The numeric keypad has 0 to 9 buttons, a '-' button for specifying negative values, and an 'Enter' button to confirm entry. These buttons can also be used to enter note durations (note values are indicated above each button) in the SY77 sequencer, and alphanumeric characters when assigning names. The keypad is to the right of the LCD window, along with the data entry slider, increment and decrement buttons, the alpha dial, cursor keys and page movement buttons. You can use the alpha dial and the increment/decrement buttons to select Voices as well. The data entry slider and increment/decrement buttons are assigned to the usual MIDI Controller numbers (6, 96 and 97, respectively).

The main purpose of these alternative ways of entering numbers is to enable you to choose whichever means best suits the task in hand. The slider is good for rapid searches through lots of values, whilst the alpha dial and increment/decrement buttons are good for homing in on a specific value. Quick editing of numbers well away from their current value, or resetting them to zero, is nicely handled by the keypad. After a while, your hands begin to remember which is the best tool for the job, and you begin to appreciate having all of them.

The inclusion of page left, page right and cursor buttons points us nicely towards the SY77 Operating System. It is a page-based user interface, with the cursor buttons being used to move an inverted video block around the LCD screen, highlighting the parameter currently being edited. Eight softkeys (F1 to F8) below the screen are used to move around between pages, and to select options, with a Shift key accessing eight supplementary softkeys. The Exit button is used to leave a page, or to cancel an action. The Jump/Mark button is used to switch between pages, and can be used with the keypad to go directly to a particular page. I have suggested to Yamaha that they use the softkeys buttons to store page numbers, as on the Roland U20.

The softkeys are used in the Voice mode: F1 is marked 'Send' and is used to transmit MIDI Program Change numbers; F8 changes the page to a display of the Voices in the current Bank, and you can use the softkeys, the cursor keys, or the keypad to move around this directory - pressing Enter loads the selected Voice; F7 shows the current assignment of the performance and MIDI Controllers - although you cannot edit these, it is only a view of how they are set up.

Below the Mode buttons on the far left are two volume sliders - the SY77 has dual stereo outputs. The other Mode buttons select the Sequencer pages: Multi, Song or Pattern, and the Utility pages. Three further buttons give control over the edit/compare, copy and effect bypass functions. Between the volume sliders and the LCD are the seven Sequencer function buttons: Go to Measure 1; Rewind; Wind; Locate; Record; and Run. There is a rotary control on the back panel, next to the LCD contrast control, which sets the volume of the metronome click used when recording a sequence - the two click tones appear mixed in with the audio output.

The rear panel houses all the input and output connections. There are two pairs of stereo outputs on quarter-inch mono jacks; a stereo headphone socket; MIDI In, Out and Thru sockets; footswitch, volume pedal, sustain switch and foot controller (assignable to MIDI Controllers 0-120) sockets; plus a breath controller socket. A captive mains lead and power switch completes the itinerary.


In Voice mode there are really only a few pages to move between: the main Voice Title page (page 100), the Controller View page, and the Bank Directory page. I soon got used to using the softkeys to select a page, and then using the Exit button to return.

Editing a Voice involves more pages, and pressing the Edit/Compare button takes you to the Voice Edit Title page (page 200). Softkey F1 is shown selected in inverted video with the word 'Mode', indicating that the 11 numbered selections are the available ways of using the Elements. One of these 11 will also be shown in inverted video - the currently selected mode. Typically, this will be Mode 9 (1 AFM and 1 AWM2 Element). Three other softkeys will be labelled in this instance: F2 'Com' leads to the pages dealing with those parameters which are common to all the Elements in the Voice; F3 'E1' goes to the editing pages for Element 1 (AFM in this case); F4 'E2' does the same for Element 2 (AWM2). Softkeys F5 and F6 will be similarly used when four Element modes are selected. In a single Element mode, only F3 will ever be used.

Selecting a mode using the cursor keys or the keypad illustrates the editing method used in the SY77 - you select a parameter by moving the inverted video block (the cursor) to it, and then change its value. Moving the cursor on this page changes the Mode. To make the change permanent, you need to store the Voice, and here another aspect of the careful thought that has gone into simplifying the operation of the SY77 becomes apparent. There is no separate Store button, and you are effectively prevented from losing an edited Voice unless you actually abandon it. If only all instruments were designed this way...

Pressing the Exit button moves to the Auto-Store page. This is similar to the Bank Directory page except that there are three softkeys: Return, Quit and Go. Return takes you back to the Mode Select page which was just exited. Quit abandons the current edit and goes back to the main Voice Title page, whilst Go writes the edited sound to the currently selected memory location. Pressing the Bank, Memory and other movement or numeric buttons allows the selection of a different destination before pressing the Go button. Once pressed, the display returns to the main Voice Title page, where a 'Store completed!' message greets you. Pressing the Exit button once more completes the edit, clearing the softkey bar and restoring the softkeys as before. The same process is followed each time you try to exit from any pages where you have made edits - you do not need to worry about changing things accidentally, since unless you actually store them you cannot cause any damage.

The Voice Edit Common parameters illustrate the way that parameters are divided into pages. Pressing the 'Com' softkey from the Voice Edit Title page calls up the Voice Edit Common page, which has 15 numbered selections:

1 Element Level
2 Element Detune
3 Note Shift
4 Note Limit
5 Velocity Limit
6 Element Pan
7 Output Select
8 Random Pitch
9 Portamento
10 Effects
11 Micro-tuning
12 Controllers
13 Name
14 ............
15 Initialise
16 Recall

The Recall and Initialise pages do exactly what they say, the rest call up sub-pages which contain the parameters themselves, although in a few cases another level of sub pages is used.

Pages are organised in levels: the title page is at the top (at ground level), and the first edit page is on the first level underground. Further sub-pages are further down. The Exit button moves up through pages, whilst the Enter button moves downwards. In the case of the Voice Edit Common pages, they are all on the same level, and this is where the page left and page right buttons come into play.

The Voice Edit Common pages provide access to all the parameters which are more usually associated with layering, splits etc. Here you can set the relative and actual volume levels of the separate Elements within a Voice, the amount of detune between the Elements, pitch transposition, and the range of notes and velocities to which an Element will respond - which gives zoning/splits and velocity switching capability. Comprehensive control of the dynamic stereo panning is possible, choosing from 64 pan presets and 32 user pan memories - using a separate Low Frequency Oscillator (LFO), the note number, and a separate five-segment Envelope Generator (EG) to determine the stereo imaging.

The Output Select page allows the Elements to be routed to either or both of the two stereo output pairs. Random pitch depth, portamento mode and time can also be controlled, and there is access to the five sub-pages containing the Effects parameters (see 'Effects' panel for details). Another page gives control over the micro-tuning — there are two dedicated tuning memories available, plus 64 preset tunings, ranging from conventional scales to quarter and eighth tones, and even a reversed keyboard. Micro-tuning can be programmed on an Element basis, so you can have a Voice with several differently tuned Elements in it.

The Controllers page has four sub-pages which allow the performance controllers to be assigned to MIDI parameters. Finally, the Name page lets you assign a name to the edited Voice.

The last two selections do not access pages, instead they act immediately when you have selected them and pressed the Enter key. The Initialisation is separate for the Common and AFM/AWM specific parts of the Elements - so you can decide exactly which areas you want to clear. Recall calls up the last abandoned edit, and can be disconcerting if you press it accidentally - just make sure that you 'Quit' from the Auto-Store function and all will be well again. The draft owner's manual called the pages 'Jobs', and this fits into the more usual Yamaha naming conventions, although 'Pages' does seem to be a clearer term.

The page system and large LCD screen makes editing and using the SY77 easy. The softkeys could be better utilised, but the rest of the user interface is well thought out and very quick to use once you have found your way around. It took me much longer to learn my way around the original DX7!


'Multitimbrality' has become the watchword of the current generation of synthesizers, since it offers better exploitation of the available sound resources - the opposite of using a DX7's 16-note polyphony to play monophonic bass lines! As with splits, stacks and velocity switching, making the best use of multitimbrality can be difficult, so Yamaha have simplified this aspect of the SY77 as well. When you are working with the SY77 as an expander, or with the on-board sequencer, you use the Multis (complete definitions of how the SY77 behaves when it is used as 16 separate synths).

Assigning MIDI channels to sequencer tracks and sounds can prove complicated in some instruments, but in the SY77 there is no problem - you can't do it! Instead, the track number is the MIDI channel number and the Voice channel automatically (you can alter the MIDI channels for the outgoing sequence information though, should you need to). So Track 1 is on Channel 1 and drives the Voice on that track. The SY77 is 16-part multitimbral and uses Dynamic Voice Assignment to make the most of the 32-note polyphony, by sharing Voices around as they become free - much as in Roland's Partial Allocation system.

In practice, the Multis free you from most of the headaches of trying to decide which channel or track is which, since you are always dealing with the same number. The Multi provides you with a virtual 16-track mixing desk, since you can control the volume, fine tuning, note shift, pan and output selection, as well as the effects setup. It is rather like having an instantly reconfigurable MIDI system made up of 16 instruments, but with no need for MIDI switchers, Merge and Thru boxes, or miles of cabling. The 16 preset Multis cover a selection of 'orchestras' ranging from solo pianos to ensembles of various types, and you can fill 16 user memories with your own Multis and store more on RAM cards or floppy disks. When you are in Multi mode, Program Changes can be interpreted as Multi selections, so you can use the SY77 with an external sequencer and still use the powerful Multi facilities.

Other MIDI features include standard master keyboard and expander type functions, like setting the output channel in Voice Mode, turning Local Control on or off, setting the SY77 to receive odd or even notes only, setting the System Exclusive device number, and protecting the SY77 from bulk dumps - this latter function is only active for bulk dumps, which could erase all of the user memory, because the Auto-Store feature means that there is no 'memory protect' switch as such.

How you select one of 256 Voices via MIDI is not immediately obvious when there are only 128 available Program Change numbers! The SY77 provides two modes: Normal mode ignores the memory and always decodes the first 64 (0-63) incoming Program Changes into a Voice number, whilst the next 16 (64-79) are used to select Multis; and Direct mode uses Program Change messages above 116 to select the memory source - Internal, Card, Preset 1 or 2 for Voice or Multis. Exactly the same messages are transmitted when you select a Voice or Multi.

Bulk dumps have a whole page to themselves. There are 12 different types of information which can be sent, from all the internal Voice, Multi, Pan and Micro-tuning data down to single Voices or just the setup portion of the Sequence data. The SY77 only supports the Yamaha N-Seq format for dumping songs over MIDI.


Next month's feature on RCM will cover the SY77's sound generation system in more detail, so here I will outline the main points which are new and improved in comparison with the DX7 Mk1 and MkII. I am assuming that most readers will have some familiarity with FM synthesis - if not, then Dr. John Chowning's and Dave Bristow's excellent book on the subject, 'FM Theory & Applications' [1986 Yamaha Music Foundation] is highly recommended. Alternatively, my series 'Practically FM' [SOS May-October 1988] may be of interest to more advanced FM programmers.

The basic thing to remember about the SY77 is that Yamaha have strived to improve both the audio quality and the functionality of FM and AWM. The sound output quality is correspondingly high - on a par with the finest digital audio equipment. In particular, most of the 'processing' noise associated with FM in the past is not apparent in the SY77.

Certain parameters are common to all the Elements (see above). Since each Element can be thought of as a complete synthesizer, these common parameters are similar to the Performance or Function settings in older Yamaha instruments, and so this is where splits, stacks, zones and velocity switches are controlled. Although the digital effects are common to all Elements within a Voice, because the Elements can be assigned to neither (this is where the stereo mix switches become important), either or both of the two output groups, there is a great deal of flexibility built in. Once you have become acclimatised to the idea of finding everything inside a Voice, it seems a natural way to work, and you may even start to wonder why all instruments are not like this.


The Advanced Wave Memory 2 section in the SY77 contains 113 basic digitised waveforms, which are stored as 16-bit linearly encoded words, with the AFM waveform also available as an extra sound source. These waveforms cover a range of sounds: a multi-sampled piano; strings; brass; orchestral instruments; oriental instruments; percussion and special effects; analogue synth sounds; residual waveforms derived by removing the pitched part of electric pianos etc; traditional synthesizer square, pulse and sawtooth waves, and more. All the internal signal processing uses 24-bit precision arithmetic, which helps keep the quantisation noise and finite precision effects at a low level. Pitch tracking can be fixed, normal, or normal with micro-tuning (which is switchable for each AWM2 or AFM Element) - which is a boon for producing sounds with components which do not need a standard keyboard span. Microtunings like eighth and quarter tones are already provided, and two user-definable tunings should cope with more esoteric requirements.

A five-stage Envelope Generator (EG), with velocity rate scaling and an optional delayed start mode, provides lots of control over the amplitude envelope, whilst four-segment output level scaling can be used to control the keyboard zoning. There is one LFO, with control over the initial phase for creating special effects at very low frequencies, and a four-stage Pitch EG incorporating velocity sensitivity for pitch modulation provides four ranges, from half an octave to eight octaves. Overall, you are given plenty of control over how the samples are played back, which is very important in producing sonic distance between the raw sample and the final sounds.


The SY77's Advanced FM provides 15 complex waveforms in addition to the traditional sine wave used by the Operators. All the calculations are made using 24-bit precision arithmetic, and there is improved resolution and bipolar control for many parameters. An Initial Phase control for the Operator and LFO Frequencies helps give more control at low frequencies, as an extension of the phase sync provided in previous FM versions. The EG is much more sophisticated, also: six-stage envelopes with delayed start, segment looping and rate velocity sensitivity. Pitch modulation is much improved, with individual Operator pitch modulation switching for the four-stage Pitch EG, which has velocity sensitivity for pitch modulation depth and four ranges from half to eight octaves. In addition, you can use the AWM2 waveform as an extra modulation source.

Some 45 algorithms are provided, with user-definable feedback and feed-forward loops, as well as a built-in noise generator. The four-stage Operator output level scaling simplifies the over-complex three note fractional scaling found on the DX7 MkII, but loses little in functionality. There is an extra low frequency mode in fixed frequency, and (at last) two LFOs - one main and one sub, which provides delayed vibrato only. And before I forget, portamento only works on the AFM Elements. It is also a Voice Common parameter, so you can't have different values for different AFM Elements. However, if you need to create slurred pitch effects you could use the Pitch EGs in place of portamento, as these are independently programmable for each Element.

The end result of all these improvements is a flexible, high quality, synthesis source which neatly sidesteps most of the problems and limitations of earlier incarnations of FM. Despite this, AFM should be reasonably easy to use for anyone who has mastered the DX7, and the page-based editing system might even have made it easier! So, the wealth of parameters and fine tuning capability make this a programmer's system which should still be editable by the knowledgable player.


The SY77's real-time digital filters are the same for both AWM2 and AFM Elements. One of them may be implemented as a 12dB/Octave low pass filter (LPF) with resonance or a 12dB/Octave high pass filter (HPF), whilst the other is always a 12dB/Octave low pass filter. The filters can also be turned off. This means that you have the flexibility to choose 12 or 24dB/Octave cutoff slopes for the low pass filter by using one or both filters. The cutoff frequency can be controlled by either an EG or LFO. The Filter EG has five stages and is not looped - there is one per filter, which makes the combinations of LPF and HPF acting as a bandpass filter with separate envelopes quite mind-boggling. The cutoff can also be controlled by the main LFO, allowing traditional filter sweep effects. The filter frequency control has 127 steps, from 0Hz up to 22kHz, and this can be varied with velocity sensitivity, LFO modulation depth, and a four-stage cutoff frequency scaling exactly like the output level scaling.

But what do the filters sound like? I was raised on analogue synthesis and at one stage could tell the difference between an ARP, a Moog, a Korg and a Roland just by the characteristic sound of their VCFs, and so I was especially interested in how the SY77 filters sounded. As you might expect from a digital synth they were clean, crisp and clear, with hardly a trace of colouration - very much a perfect filter sound. As you increase the resonance the transition into partial oscillation is smooth, and emphasises the harmonics very neatly without any problems - this sort of treatment is especially wonderful on string sounds. The filter applications will suffer slightly because of the single cutoff modulation sources (EG or LFO), so for special effects that need more than one filter modulation source, an old monosynth is probably still the best.

In conclusion, these filters are hardly the digital replacement for the purist who wants the Moog VCF of old, but they make very pleasant listening and, most important of all, the filtering will be consistent across all SY77s and all sounds, unlike most analogue filters.


This is a dream of an instrument. I am completely converted to RCM synthesis, and have already sold my DX7 and ordered an SY77! At present there is really only one serious contender to the SY77 - the Ensoniq VFXSD.

Both instruments have similar filtering and effects, although the VFX leans more towards synthetic sounds and has no strong piano sound, the SY77 does. The SY77 has a mixture of realistic and synthetic sound capability, 32-note polyphony (only 21 in the VFX), 16 instrument multitimbrality with 16 preset and 16 user Multi memories (the VFX has one), and 192 Voices instantly available (only 20 Presets for the VFX, or 60 if you count VFX Programs instead). The SY77 offers a more powerful synthesis method with its mix of AFM and AWM2, and has two pairs of stereo outputs, but the VFX scores on its interaction between performance controllers and effects, the increased track and note capacity of its sequencer, and the polyphonic aftertouch (although the feel of the keyboard has been criticised and may require some adjustment in your playing technique).

I must admit to being biased in favour of FM, and so my vote goes to the SY77 - mainly because I can't help thinking that an FM synth added to sampled sounds has got to be more powerful than just a set of (short) sampled waveforms. If you want a DX7 replacement, then there is simply no competition - I expect the DX7-to-SY77 voice conversion programs (mine included) to start appearing by the middle of 1990! I loved the SY77. I have been waiting for quite some time for something which would enable me to replace my ageing DX7, but also provide a wider range of timbres. The SY77 exceeds my expectations and I have no qualms about praising it ecstatically. With one SY77, you could virtually throw away most of the rest of your equipment (with the exception of your sampler), so the £1999 price begins to look much more reasonable in this context. By bringing together their expertise in AWM, FM and Signal Processing, Yamaha have set a new standard in mixing synthesis with sampling to produce the most exciting synthesizer I have ever seen or heard! This is a performance instrument par excellence, with great sounds, huge potential, and an interactive sequencer all in one. In a word - wicked!


£1999 inc VAT.

Yamaha-Kemble Music UK Ltd, (Contact Details).


  • 61-note keyboard (C1-C6), Velocity and Aftertouch sensitive.
  • 16-note polyphonic AWM2, 16-bit linear 32/48kHz sampling.
  • 16-note polyphonic AFM, 8 operators, 45 algorithms, 16 waveforms.
  • Real-time digital Filters (up to 8 per Voice).
  • 128 preset Voices, 64 user memories.
  • 16 preset Multis, 16 user Multis.
  • RAM card and floppy disk storage.
  • Sequencer: 15 tracks plus dedicated pattern track, 99 patterns, 1 song, 32-note polyphony, 16,000 note capacity, real/step-time recording, punch-in.
  • 4 separate Effects Processors, 40 Reverb programs, 4 Modulation programs
  • 2 pairs of stereo outputs (4 individual outputs)


The Sequencer and Multi modes work together very closely - you will find yourself moving between them all the time whilst using the SY77 as a music workstation. Multis work on the bank, memory and number, not the Voice name, so you need to keep Multis and Voices together otherwise your Multi will use the wrong sounds! It is a good idea to always save the synth data with the song data on the same disk. If you think about it, this is exactly the 'instant total recall' which has been the goal for software packages like Dr. T's Xor program, and here it is as a built-in feature.

I am never completely happy about reviewing on-board sequencers, as a full review could occupy an entire article on its own. Unlike a software sequencer, you have no opportunity to change a hardware sequencer unless the manufacturer releases a ROM update. To paraphrase the WYSIWYG acronym used for word processors, it is a case of 'what you get is what you use'! Hardware sequencers are not normally my first preference, but the reviewer's art demands, and so I used the SY77 to produce a couple of songs to check that what you get is actually usable.

I am pleased to be able to report that the SY77's sequencer is a very friendly, carefully thought out piece of work, which makes the process of creating a song relatively intuitive and straightforward. I discovered this without the aid of an owner's manual (few prototypes ever have a manual), so it can't be that difficult! In many ways the V50's sequencer has had a direct influence on the SY77 design - it uses the same buttons to select tracks for recording, playback or editing functions, and there is a wealth of editing and quantising functions to help tidy up the stuff you record.

The sequencer is a single song, 15 track plus dedicated pattern track, 16,000 note capacity, 32-note polyphonic, 99 pattern device. Only one song? You only need one because you can always load another off disk, and so 99 patterns seems adequate in this context. 16,000 notes is certainly enough to try out most ideas for songs, although the actual capacity will decrease if you use aftertouch or controllers, of course. The Korg M1's sequencer was criticised for its small memory and restricted number of patterns, but the SY77's disk drive means that it does not suffer from the same problems, and so can fulfill either a workstation or musical notepad function.

Recording can be in real-time or steptime, with punch-in, overdub and replace modes. You can only record on one track at a time, but this fits into the structure of Multis and Voices, and is not a severe limitation in most cases. Measures can be of different lengths and time signatures, and the tempo can be varied on an event basis, should you need tempo changes per note! Controllers like aftertouch, program change and pitch bend can be inserted after the basic note information has been recorded, if you wish.

Track editing can be in the form of individual events or with a graphic representation of the keyboard in the LCD, showing the played notes. The SY77 soft-keys, below the display, come into their own here by providing instant access to relevant functions. The alpha dial, increment/decrement buttons and sequencer location buttons are all used to allow movement through the song. There are 16 editing jobs: Quantise; Alter gate times of notes, Modify velocity; Crescendo and Diminuendo; Transposition; Thinning out of Controller data; Erasing events; Shifting notes (for matching drum sounds to other drum machines, etc); Moving a track backwards and forwards in time; Copying, erasing, deleting and inserting measures; Mixing down tracks. Erasing tracks, and the rather perilous Clear Song.


The SY77 keyboard is velocity and channel aftertouch sensitive, and is not weighted. It feels very similar to the keyboards on other recent products (V50, YS100/200, DX11, DX7II etc) - ie. slightly smoother and quieter in action than the original DX7. It protrudes slightly from the casing, which has its good and bad points: it is easy to play, with no end-stops to jar your fingers, but it might be prone to damage on the road. In common with most modern instruments, there is no piano-style (DX7-style) felt strip to collect the dust!

The aftertouch response is very similar in feel to other Yamaha synthesizers, and is perhaps a tiny bit on the heavy side for my taste - I would prefer something like the softer, more responsive, feel of the Roland D50. The point at which the aftertouch begins to have an effect felt slightly higher in the key travel than I am used to, but the pressure-sensing strip may just need to be played in for a while.

The pitch and modulation wheels are the new, wide, deeply ribbed design for better grip - much lighter and not as damped as the older, narrower wheels found on the DX7. Some 'pull and release' pitch bend techniques tend to overshoot and sound funny - you need to damp the return to centre with your hand (rather like string damping on a guitar) to prevent this, but it might end up being exploited as a performance technique! The second modulation wheel is centre detented, although the detent is quite subtle, and so can be used for smoothly controlling parameters up and down in value without catching at the centre position; it replaces one of the performance-based continuous sliders on the DX7 MkII. The SY77's data entry slider can double as an extra realtime performance controller (eg. for filter cutoff frequency), and its position in the centre of the keyboard makes it usable with either hand when performing.

Unfortunately, the alpha dial and increment/decrement buttons cannot be used as performance controllers because they are assigned to Voice control. (Although you can assign the increment/decrement buttons to Controller parameters, the Voice selection takes precedence!).

Any external MIDI device (MIDI Controller numbers 0-120) can be a controller - the display shows the defined names where appropriate. Because many of the performance oriented parameters in the AFM and AWM2 Elements are now bipolar (that is, they can be positive and negative), it is easier to add sensitivity to velocity and aftertouch because there is less need to pull up in level and then reduce by adding sensitivity, as on the older FM synths.

Pitch Wheel
Aftertouch Pitch

Selectable: (MCN 0-120 and Aftertouch)
Pitch Mod depth
Amplitude mod depth
Filter mod depth
Pan Bias
Volume Low limit
EG Bias depth
Filter Cutoff EG modulation depth

There is no space to put more than one extra floppy disk near the disk drive (pity), but you should be able to fit quite a lot of data onto one disk - based on the RAM inside (256K), you should be able to fit at least three 16,000 note sequences (songs) onto each disk, together with at least one set of Voices.

Strangely, the headphone and breath controller sockets are sited on the back panel. This makes using them less convenient than on previous machines, as you may find that the leads get in the way of your hands and arms when playing. Incidentally, the output sockets and MIDI connections are located on the right-hand side, when the SY77 is viewed from the front - unlike almost every other keyboard. Still, all sockets are clearly marked in white lettering on the top and rear panels, facilitating easy connection from the front.


The SY77's Drum section is like a special case of a Multi - you can assign each of the 61 keys on the keyboard to a separate AWM2 waveform at any pitch, and allocate various other parameters like volume, static pan position, and output group. A special 'Alternate' switch lets you specify drum sounds which will not play simultaneously - like open and closed hi-hats, for example - the last drum sound played will cut off the previous one in this case. Drums steal notes from the AWM2 polyphony when they are playing, and so the SY77's dynamic voice allocation is important in maintaining a high apparent polyphony.

The sequencer patterns are ideally suited to use with the drums. Track 16 of the sequencer is dedicated to patterns, and contains pattern numbers and repeat marks in much the same way as a musical score. Patterns are useful because they can be re-used within a song many times and only the reference to the pattern number is recorded each time, not the pattern data itself. This can save a huge amount of sequence memory if you use repeated patterns, eg. for drums or bass lines.

Pattern recording and editing is almost exactly the same as for sequences, although the jobs are restricted to copying a pattern, getting a pattern from a track, inserting a pattern into a track, and chaining patterns together. The only problem is that patterns only play on one channel, and so you cannot hear a pattern in context with a sequence. They are therefore best suited to prior planning rather than improvisation, although you could use the 'Get Pattern' job to quickly turn parts of a previously recorded track into patterns.


Four digital signal processing (DSP) blocks are available - two are used for modulation effects (4 types) and two for reverberation-based effects (40 types). The effects can be arranged in three ways, and this allows you to select how the two output groups are effected. When sequencing, only one Effect can be active at once (the one in the Multi definition itself, although it does seem to default to the drum effects unless the Effects Edit page is called up when in Multi mode).

The effects processors are similar to the REX50, SPX90 and FX500 units, with 15kHz bandwidth, maximum delay/echo times of 300 milliseconds, and longer reverb times than you will ever need! The quality of the reverbs and other effects is as high as ever and I could find little to fault, except perhaps a plea for the full 20kHz bandwidth and longer delay times. The tone controls are useful, and the distortion settings can provide additional colour to sounds other than electric guitar simulations. The provision of feedback for some of the effects, like early reflections and gated reverb, also provides some creative possibilities.

All the effects are mono in, stereo out. This means that the Stereo Mix feature needs to be active if you want any dynamic panning, since the summing at the input of the effects will otherwise destroy the panning effects. As the SY77 offers two audio output groups, it is possible to use dynamic panning on one stereo pair and effects on the other, allowing you to treat some instruments within a Multi differently from others. This can be especially useful if you do not want your drum sounds to be wallowing in reverb, for example. In Multi mode, panning can be static with fixed positions in the stereo field, or can remain as specified in the Voice itself - particularly useful for drums, where you do not usually want to have all the drums in one position.

Series - "Yamaha SY77"

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A Visit From The Doctor

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Gajits Sequencer One

Publisher: Sound On Sound - SOS Publications Ltd.
The contents of this magazine are re-published here with the kind permission of SOS Publications Ltd.

The current copyright owner/s of this content may differ from the originally published copyright notice.
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Sound On Sound - Jan 1990

Donated & scanned by: Mike Gorman


Yamaha SY77

Part 1 (Viewing) | Part 2

Gear in this article:

Synthesizer > Yamaha > SY77

Gear Tags:

Digital Synth
FM Synth
FM 6-Operator

Review by Martin Russ

Previous article in this issue:

> A Visit From The Doctor

Next article in this issue:

> Gajits Sequencer One

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