Is it a hi fi? Is it a compact disc? No, it's Yamaha's latest slice of FM technology, the FB-01 Sound Generator. And very smart it is too, in more ways than one.

As its name suggests, this is a keyboardless, 8-voice expander module with the same four operator, eight algorithm FM architecture found on the cheaper DX synths — the 21 and 100 — and on the CX5M music computer. Unlike those machines though, and uniquely in the Yamaha DX range, the FB-01 operates in both Poly (Normal play) and mono mode, ie each of the eight voices can be set to respond on a different MIDI channel. This clearly enhances the use of the FB-01 both as a 'slave' sound source for mother keyboards, and as a sound source for hard — and software — sequencers.

First appearances do definitely suggest the world of pro hi fi rather than pro audio. Tastefully finished in standard DX black, the squat, oblong metal-cased unit (measuring 218 x 48 x 274mm — WHD) sports only eight multifunction buttons and a well-lit orange(!) 16-character LCD on its slightly tilted front face.

Round the back, it's even more minimalist — just a stereo pair of jack sockets for Audio out, MIDI In, Out and Thru, a recessed memory protection switch, the main power switch, and a tethered mains lead. Ah, but what it can do.

Operation

The FB-01 has no less than 240 preset instrument sounds stored permanently in ROM, room for a further 96 voices in RAM — providing you have a computer and the relevant voicing software — four preset ROM 'configurations' (sophisticated performance patches) and 16 user Configurations — which you can access on the machine without the assistance of a computer. It all adds up to a lot of parameters to take in, so it comes as something of a relief to discover that finding your way around the various menus and sub-menus follows a logical and easily understood pattern. The eight multi function keys are colour coded into four groups. The two green keys, System Setup and Inst Select (first and second in the top row) are 'Global Menu Keys', ie those which govern the highest levels of the FB-01's operation. System Setup, for example, in conjunction with the white Data Entry/Yes-No keys, selects and saves the current Configuration (performance patch), Combine on/off (whether or not to call up pitch bend, portamento etcetera with a chosen voice), and handles some of the more esoteric functions like MIDI Data Dump (you were wondering what an expander was doing with a MIDI Out socket, weren't you?)

The second green button, Instrument Select, is used to select a particular instrument, whose parameters you may then dial up on the two blue buttons, Instrument Assign and Function. An Instrument is a grouping of any number of notes, up to eight, of a single Voice. Thus you could have an Instrument comprising eight-note polyphonic Strings, eight separate monophonic Instruments comprising a different voice for each available note, or any combination between — perhaps a four-note piano, a two note brass, and monophonic bass and synth lines.

Using Inst Select, Assign and Function in combination, it is thus possible to allocate from one to eight notes to each instrument, to set High and Low Notes per instrument (thus effectively giving you an eight-way keyboard split, whose zones can overlap), to assign stereo panning to each Voice (L, R, or L+R), Detune (-64 to +63), and Output level (0-127). This last is particularly useful bearing in mind the absence of separate Outs for each of the eight voices, since it allows you to 'mix' onboard. LFO effects for Voices which incorporate it (for vibrato etcetera) may be toggled on or off from Inst Function too. Finally MIDI Channel can be set for each voice. What actual Voices you choose to allocate to each Instrument is of course the responsibility of Voice select.

You'll be relieved after that little lot to hear that the FB-01 has a smart approach to all this editing, so when for instance you've set up two Instruments of four identical Voices each, you'll only have to detune one of the Instruments once to get a chorussing effect.

Put into plain English it simply means that, given a little time, you can choose your own set of up to eight voices from the list of 240 (arranged in seven banks of 48), stack or split them any way you like on any combination of MIDI channels you like, and store the whole lot complete with portamento, pitchbender range, modulation response to Touch, Mod Wheel, Breath, or Foot-pedal, Detuning, and individual output levels, to any one of the 16 Configuration memories for good.

And if that's still not enough, there's always the four ROM Configuration memories, Yamaha have thoughtfully set them up to offer the four most likely uses to which you'll put the FB-01, so here you'll find 'Skeleton' configurations for 'Single' — full eight-voice polyphony on a single voice, 'Mono 8' — eight separate voices suitable for control from a mother keyboard or sequencer, 'Dual', for playing a single 'stacked' sound of two voices combined, in four-note polyphony, and 'Split' — a single keyboard split with separate voices of four note polyphony either side of the split point.

All of these skeletons can, of course, be loaded with your own choice of voices and control options, and then stored to one of the user locations.

Voices

The immediate temptation in investigating the voices supplied with the FB-01 is to compare them with those of the DX7; a little unfair, perhaps, but the FB-01 doesn't come out of it too badly, particularly as keyboard velocity may be assigned to envelope shape. The lack of two additional operators doesn't really become apparent until you move onto complex sounds like pianos, where you might find that you don't get any additional crunch or bite when you hit the keys harder. This is because all the operators are busy providing the basic sound. If you don't mind four-note polyphony, you can of course stack two sounds. Or you can use two FB-01's together, which is not such a daft idea when you consider you can have four for the price of one DX7. This prospect is massively enhanced by a very thoughtful addition to the FB-01's System Set-Up menu; in normal use, of course, the unit will respond to all MIDI note numbers. If you feel like using a pair of them together though you can, from this menu, opt to set each machine to respond only to Odd or Even notes, effectively turning the two units into one, eight-operator FM sound source with full 8-note polyphony. (That is, unless you're into some very weird Jazz chords.) Brilliant.

Glancing through the Voice list supplied in Yamaha's brief but clear manual you're immediately struck by the amount of duplication there is. The 240 sounds, a stupendous number admittedly, and grouped into 'famililies' of Strings, Brass, Wind instruments and so on, nonetheless feature amongst others no less than eight Electric Organs, seven Synth Basses, and 25 Piano or Piano-style voices. A function, no doubt, of the lack of any on-board editing facility. At least this way, I suppose, you've got a fair chance of finding a sound close to your ideal. On what is essentially a preset machine, I feel this logic could have been extended to the exclusion of some of the less relevant 'effect' sounds. Still I expect someone will find a use for them and to be fair there are a lot of striking, classic DX sounds here. The selection of basses in particular is superb, as are many of the plucked, metallic, and percussive sounds. Anyone who has heard a DX100, 21, or 27 will know what I mean.

Summing Up

Yamaha have spent a lot of time and effort in developing this latest offspring of the DX family — and it's paid off. The FB-01's value-for-money capabilities, user-friendliness and flexibility for keyboard player and sequencer fan alike will breathe new life into a line which was beginning to look exhausted, and possibly extend the appeal of FM still further to those who baulk at the thought of programming. Though the manual is characteristically terse on this point, it seems that people who like to fiddle about with their sounds won't be too left out either, providing they have a micro. Yamaha, of course, are developing a Voicing Program for their own CX5M. Of the independent software houses, EMR look like being the first off the mark, with a package which will run on their own interfaces for virtually all home micros, and which will be bundled free with the FB-01s they themselves are hoping to sell over the next few months.

Somehow, I don't think they're going to have to hope too much...

Yamaha FB-01 FM Sound Generator - RRP: £299.