• Yamaha TG55
  • Yamaha TG55
  • Yamaha TG55
  • Yamaha TG55

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Yamaha TG55

Tone Generator

It's not simply an SY77 in a rack, more an alternative application of Yamaha's latest synthesiser technology - Ian Waugh gives the TG55 a full workout.

Although it's Yamaha's SY77 synth that's got everybody talking about "industry standards" and "flagships" again, the company's new TG55 expander is sure to make a lot of friends.

THE TG55 WAS launched at the same time as Yamaha's new mega synth, the SY77 (see review MT, Jan '90), but surprise, surprise, it's not an SY77 in a box - a quick look at the price will tell you that. Instead, housed in the 1U-high, 19" rack-mount casing is a near-equivalent of the SY77's AWM2 section. AWM2 is an acronym for Yamaha's second generation 16-bit Advanced Wave Memory, a digital waveform storage and reproduction system. For the technically-minded, the waveforms have been sampled at 32 or 48kHz with 24-bit internal processing and 22-bit digital-to-analogue converters. The result is sonic clarity par excellence.

The TG55 contains two megabytes of sampled waveforms in ROM (the SY77 has 4Meg of wave memory) giving a total of 74 built-in waveforms (the SY77 has 112 waveforms). Additional waveforms will become available on cards which can be inserted in the waveform slot on the front of the unit and Yamaha promise to keep users well-supplied, so increasing the potential and sonic variety of the unit.

Although the TG55 could technically be called a sample playback module, in practice it's actually rather more than that.


LET'S LOOK AT the switches n' stuff before delving deeper into the TG55's internal architecture. The front panel sports a two-line LCD and a set of clearly-labelled buttons. Actually, they're mini rocker switches and you have to press the bottom half to make them click.

To the left of the LCD are switches to select Voice, Multi (for multitimbral use - more about this in a moment), Utility and Demo modes. Might as well say now that the demo tunes are superb. You'll be impressed.

The switches to the right of the LCD are used for selecting Voices and editing parameters. Voices and Multi settings are stepped through using +/yes and -/no buttons. You can also scroll quickly through them by holding the Enter button and turning the Data Entry knob. If you play keyboards, you'll soon learn how to do this with one hand.

The TG55 has 64 preset Voices, 64 programmable internal Voices (these are initially duplicates of the presets - shame) plus the ability to access 64 or 128 Voices on an optional memory card. There are 16 preset Multis and 16 internal ones and they can be stored on memory cards the same way as Voices.


AND SO TO play. The TG55 has two modes of operation - Voice and Multi, it's interesting to note that there is no Configuration setup (as on the FB01) or Performance mode (as on the TX812). Multi mode was designed to exploit the TG55's multitimbral facilities and that's exactly what it does.

In Multi mode, Voices are assigned to a MIDI channel, not the other way around (as in Performances on the TX81Z, for example). This really does make use with a sequencer very simple to use, and it resolves the continual problem of deciding which channel to stick which sound on - there are your 16 channels, assign them sounds as you see fit.

As a consequence of this, however, only one Voice can be assigned to each channel. To play the same line with two sounds using a sequencer is no problem - simply use a ghost track or copy the track and assign the second track to a different channel. For live use, however, it means that you won't be able to play two sounds from one keyboard unless it's capable of transmitting on two MIDI channels at the same time (as can some master keyboards).

A Multi Play setup includes Voice/channel assignments, individual Voice volume, note shift, tuning, panning, effects settings and output assignments.

The TG55 is 16-note polyphonic and Voices are assigned dynamically during play in order to maximise the polyphony. For example, if all 16 channels are playing a note simultaneously, each Voice will only be able to play one note. But if four channels stop playing, another channel could then use those extra four notes.

The assignments are handled automatically by the unit, a far superior - and more transparent - arrangement to that found in some other synths in which you must specify how many notes are required for each sound. You can, however, also reserve a minimum number of notes for any channel to ensure important lines don't drop out when the polyphony gets heavy.


EDITING IN ALL modes is conducted through a series of pages. In Multi mode, for example, the first page shows the Voice/channel assignments, the second shows the volumes, the third the note shift offset and so on. All functions are clearly labelled in the LCD. The pan position is shown numerically and by a little graph - cute. New Multi setups and Voices can be given a ten-character name.

There are several copy functions to make editing easier. For example, you can copy the assignments from a channel in a Multi Setup to any other channel, you can also copy the effects setting from one channel to another. In Voice mode you can copy envelopes and effects from one Element to another (Elements coming right up).

The creation of new Multi setups is very easy, largely due to the informative LCD and the logical division of the editing functions into pages.


OK. TIME TO see what makes the TG55 tick - and produce all sorts of other sounds, too.

A single Voice is composed of one, two or four Elements, each of which can be assigned one of the 74 waveforms. A one-Element Voice will have full 16-note polyphony, a two-Element Voice will have eight-note polyphony and a four-Element Voice will reduce the polyphony to four notes. Most of the presets use one or two Elements but a dozen use four.

Element parameters include individual volume level, note shift, detune, low and high note limits (for creating zones on a keyboard), low and high velocity limits (to determine what velocity range they will respond to), pan setting, output assignment and effect balance (between dry and processed signal).

Each Element has its own five-stage amplitude envelope and pitch envelope plus two filter cutoff envelopes. Associated envelope parameters include rate scaling, which allows the overall decay rate to be varied across the pitch range: level scale breakpoints and offsets, which allow variations in levels to be sited at four points across the pitch range: velocity, pitch and amplitude modulation sensitivity and depth: seven LFO waveforms: and LFO speed, delay and phase (talk about subtlety). Each Element can play in normal or fixed pitch mode. In fixed pitch mode all notes produce the same pitch.

"Sounds are decidedly varied - I'm tempted to call them idiosyncratic, although perhaps adventurous would be more appropriate."

And then there are the filters. Each Element has two filters. One is switchable between high-pass and low-pass and the other is low-pass only. The cutoff slopes are 12dB/octave. If both are low pass they work as a 24dB/octave filter. In high pass/low pass combination they produce a band-pass filter.

Both filters have resonance controls (in low-pass mode) which can boost them into self-oscillation. As well as control by their own envelopes, the filters can be patched into the Element's LFO. Filter parameters include rate scaling and level scaling; resonance, velocity and modulation sensitivity. I'm sure you get the idea - let's say editing on the TG55 is comprehensive.

Voice Edit mode is also where you control the controllers. This includes setting the pitchbend range, aftertouch bias, random pitch range (produces random pitch changes to simulate instruments in which each note is rarely in perfect tune with the others - the clavichord and string ensembles, for example); and amplitude, pitch and cutoff modulation. In addition, you can assign any MIDI controller to amplitude or pitch modulation, filter cutoff and so on.

Editing and movement through the parameters is on similar lines to Multi mode, although there are more pages to flip through and more buttons to press. Individual Elements can be selected and switched off by holding the Select button and pressing one of the buttons to the left (almost the only appearance of the multi-function button syndrome).

Each Element has nigh on 100 associated parameters (more if you include the effects and controller settings) and the selection procedures make these as easy to access as possible although inevitably there are a lot of pages to get lost in. If in trouble, however, the Exit button returns you to the previous edit page or function so while you may lose your way you'll never get lost.

No doubt voice editor software is already being written. This will make the job of editing that much easier, especially if it also allows access to the waveforms on plug-in cards. The advantages of being able to see all parameters on a VDU - especially in graphic form - is not to be underestimated. Thank ***» for computers, I say.


NOW THAT WE know how it works, what does it sound like?

The sounds are a decidedly varied and assorted bunch. In fact, I'm tempted to call them idiosyncratic although perhaps adventurous would be a more appropriate description.

Gone are the lists of piano, organ, guitar, bass, choir and brass presets which you might expect to find on a sampler (although there are many sampled waveforms of all these). Instead Yamaha's programmers have tried to create sounds which are a little different. For example, there is no straight choir - 'St. Michael' produces bells when you release a note, 'Voyager' has a lot of breath (chords with "sizzle', as the manual describes it). The closest to a straight choir is 'Mystichoir' in which the voices swell up and shift in tone. But nice, really nice.

'Zarathrusta' is a big orchestra sound complete with swell (yep, just like the record of almost the same name). The brass volume is patched to the modulation wheel.

The 'Distorted Guitar' is absolutely superb. If you hold a note it degenerates into feedback (this sound was produced using violin and triangle waves with help from the distortion effect).

'Oriental' is an oriental orchestra. It is made up of only two Elements - strings and shamisen - but put together (detuned and so on) beautifully. Anyone with an oriental bent will also enjoy 'Gamma Band', a percussion ensemble made from piano, flute, shamisen and glocken.

If it's sweeps you like, check out 'Spirit VCF', an analogue sound with a long slow filter sweep.

There are six pianos, some acoustic, some electronic. One of my favourites is 'Piano Mist', a piano with bell overtones. The acoustic pianos are similar to those in Yamaha's EMT10 and TX1P although just a touch more percussive, perhaps, and brighter although they don't use so many multisamples.

Play 'Thumb Bass' hard and you get a slap bass sound. And there's a racy wood bass in the left-hand section of 'WdBass Duo', too.

It's interesting and informative to see how the sounds have been produced: the combination of Elements used and how they've been processed. Some, which sound like instrument samples, have in fact been created with analogue-type waves. Many Voices use the modulation wheel to add modulation (of course), change the tone or fade Elements in and out.


A FEATURE OF most current synths is the inclusion of a separate drum section. The TG55 has one, too - or rather it has two, too. Voices 63 and 64 are composed of 61 Elements each corresponding to the keys from C1 to C6. A different drum sample (or any of the 74 waves) can be assigned to each key. There are actually only about 16 dedicated drum samples but each can be detuned and transposed to produce a wide range of drum sounds.

You can specify drum Elements which will not sound at the same time - open and closed hi-hats, for example. The drum sounds reduce the total polyphony of the instrument so the dynamic voice assignment is particularly useful when playing drum tracks.

Other editing controls are similar to those available for Voices and include volume, pan, effect balance and output assignment. As in the other edit modes, there are several copy functions to let you transfer parameters from one drum Element to another.

"A feature of most current synths is the inclusion of a separate drum section. The TG55 has one, too - or rather it has two, too."

The drum samples are all usable and mainly based around a traditional kit. But check out 'Vocal Ga', for example, which sounds like the attack phase of someone being sick (any punks out there?).


MANUFACTURERS HAVE WELL and truly realised that a smattering of reverb can make just about any sound twice as appealing and few instruments are now released without a digital effects section. The TG55 is no exception. It has 34 effects in a slightly simpler arrangement to those on the SY77 (although they are broadly similar). They can either be applied to a Voice or not (although the balance between wet and dry signals can be adjusted, as mentioned earlier).

In Multi mode, independent effect parameters can be selected for each Multi setup. Alternatively, the effect assigned to any one of the 16 channels can be used.

Effect types include reverb, delay, pan, feedback, tone control, distortion and various combinations of these. You can alter three parameters per effect (such as delay time, filter, gain, delay and brilliance) which varies according to the effect.

They're no substitute for an SPX90, Multiverb or Quadraverb, but for built-in effects they do an excellent job. I won't gripe at all.

Utility offers a subset of the Utility functions on the SY77. These include master tune, transpose, velocity curves (choose one from eight), MIDI receive channel, MIDI device number, bulk dump protect (to prevent the accidental wiping of the memory) and several memory card options such as format, load and save. Bulk dumps via MIDI can handle Multi, Voice, System and All data.


MIDI CAN ONLY handle 128 program change numbers and if an instrument has more than 128 sounds manufacturers have to decide how to access them all using just 128 messages. A common method is to employ a program change table which lets you assign any incoming message to any internal sound. But that still only lets you select 128 sounds at any one time.

With the TG55 (and the SY77) Yamaha has adopted a different method. Program changes from 0 to 63 select the voice number, 64 to 79 select Multi setups and those between 119 and 127 allow 'selection of the various TG55 modes'. The manual could be a bit more informative here, but basically these messages let you select the preset, internal or card bank.

It's easier than a program change table in many ways as you don't have to preselect a voice list first, although some voice changes will require two program change instructions.


THERE ARE MIDI In, Out and Thru sockets, of course, while Left and Right stereo Outputs cater for the audio signals. There are also two Individual Outputs and voices can be assigned to either or both of these. In Multi-play mode, therefore, voices can be split across four outputs.

As more and more semi-pro and home musicians are producing stereo recordings this arrangement is very useful, as voices can be assigned a position in the stereo field before leaving the TG55. If you want greater control for additional processing you use the Individual Outs.

The manual is quite long at 140 pages, but it is clearly-written and well laid-out. A tutorial section shows you how to select Voices and create Multi Play setups and do some simple editing. The reference section contains the meaty programming bits. Functions are described comprehensively under four headings: Summary, Settings, Procedure and Details. Cross references are also included.


YAMAHA DESCRIBE THE TG55 as a Tone Generator, not a sample playback module. In essence, it uses sampled AWM2 waveforms as the basis for its synthesis so they're not telling any fibs. The presets, too, indicate that the programmers want to show its potential as a "tone generator' and not (just?) a machine capable of regurgitating piano, brass, string and choir samples. And they've done their job well.

However, because of that very fact, if you're after a playback sampler first and foremost, you may initially be disappointed by the range and number of presets of an imitative nature (although those that are imitative are generally good and some are truly excellent). But before you dismiss the TG55 as a sampler, remember that you can create your own sounds (ten of the supplied waveforms aren't even used in the presets) and don't forget the plug-in waveform cards which can add up to 99 new waveforms to the machine (these were not, alas, available at the time of the review so I can't comment on their contribution to the performance of the instrument).

If you're looking for other reasons not to buy a TG55; it has no alternate tunings (anyone use these? Write to Communique...) and its 16-note polyphony, while quite respectable, is not quite as inviting as the 32-note polyphony of some other machines. But then it has built-in digital effects and a separate drum section.

But samplers aside, as an expander and an extra/alternative source of sounds the TG55 scores highly. At the end of the day, it's whether or not you like the sounds the machine produces which determines whether or not you can live with it and use it. And I like what I heard on the TG55. In fact I spent most of the review just playing the sounds and creating new ones by swapping Elements. I'll be really sorry to see it go.

If you like what you've read so far but fancy a keyboard as well, thank your eagle-eyed reviewer for spotting a reference in the manual to an SY55 (page 109). The manual was stamped "Preliminary", so this may just be a twinkle in an R&D boffin's eye but it looks like a keyboard version of the TG55 could be on its way.

Meanwhile, the TG55 will be appearing in a music shop near you anytime now.

Price £749 including VAT.

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Live And Direct

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An Oberheim In Time

Music Technology - Copyright: Music Maker Publications (UK), Future Publishing.


Music Technology - Mar 1990


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Gear in this article:

Synthesizer Module > Yamaha > TG55

Gear Tags:

Digital Synth

Review by Ian Waugh

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