For this issue I have the pleasure of assessing two instruments at opposite ends of the synthesiser spectrum — the Yamaha GX-1 and the Korg Micro-Preset. Although aimed at rather different markets, both these Japanese instruments have a great deal to offer musicians.

Yamaha (who now seem to make everything from motor cycles to toilet seats) have made a claim for world dominance with the GX-1. Although positioned at the top of the Yamaha Electone organ range, the GX-1 is regarded as a polyphonic synthesiser — many of its facilities are common to the better known CS-80. The best known piece of music employing a GX-1 is Fanfare For The Common Man (a top ten hit for Emerson Lake and Palmer in 1977), which demonstrated only a fraction of the instrument's capabilities. It is also the instrument Stevie Wonder calls his 'Dream Machine', and having heard a lot about it, especially the price, I had built up a rather awesome image of the instrument. On being confronted by the device I must say that even my expectations didn't do the instrument justice. I was impressed.

The GX-1 consists of two 61-note 8-voice polyphonic keyboards, a 37-note monophonic keyboard, and a 25-note pedalboard, all of which is housed in a white fibreglass shell, complete with adjustable bench. The instrument is split in such a way that the bench and pedalboard can be detached and the remaining keyboard section easily lifted by eight people! (It weighs about a third of a ton.) A detailed description of the instrument would, I feel, be rather heavy going and take up a lot of space, so I've included a layout of the GX-1 to show some of the machine's facilities; I'll briefly discuss some of them and refer to the diagram.

The two polyphonic keyboards (upper and lower) and pedalboard have 20 associated presets — the monophonic (solo) keyboard has ten — and these are selected by illuminated pushbuttons at the top centre of the facia. The relative pitches of these presets are controlled by the overtone slide switches to the left of the tone push switches, and the presets are set by tone modules that are housed in racks in the top of the instrument, using the box of tricks that can be seen sitting on top of the GX-1 in the photograph. This enables all the commonly accepted synthesiser functions — waveshape, envelopes, filters etc — to be programmed.

The other controls on the panel above the solo keyboard (PN-1) are reasonably self explanatory. One interesting facility, however, is the coupler; similar to that on a church organ, this will couple up any two keyboards (or pedalboards) so that a more complex or fuller sound can be obtained.

(PN2) and (PN3) carry the controls associated with the solo keyboard. This has all the facilities of a normal one-oscillator monophonic synthesiser, but in addition the keyboard has a 3-way touch response system. The keyboard is sprung so that it 'bounces' up and down — on pressing a note the key itself will move down, then by pressing harder the whole keyboard will tilt down — one touch response position. Further pressure will cause a second touch response, and by applying sideways movement to the note a third response is obtained. These touch responses can be used to control different parameters, switches for these being on (PN3).

(PN4) and (PN5) have the modulation and touch controls for the upper polyphonic keyboard. This has an eight note capability, each note having two channels (I and II). Portamento is available on this keyboard and, like various modulation elements can, if required, be introduced by the knee lever. The lower keyboard is almost identical to the upper, the controls being housed on panels (PN6) and (PN7). However, on (PN6) there is a rhythm unit — this is an extremely good module, and I say that as one who normally hates 'drum machines'. There are 16 preset rhythms contained on two banks (A and B), so that two rhythms can be balanced against one another. There is also a swinger control that allows you to make the beats in the bar uneven so that more interesting rhythms can be obtained. This is a simple to use yet effective unit that can be triggered by hand or by the footswitch on the expression pedal.

In between (PN5) and (PN7) there is a row of five push switches which change the response that the expression pedal has over the volume of each keyboard, pedalboard or rhythm unit. This enables one to fade certain sections down without drastically reducing others.

(PN8), which is housed beneath the lower keyboard and pulls out rather like an ashtray, contains the controls for fine tuning the instrument and also presetting the footages of the channels for the two polyphonic keyboards and pedalboard. The latter are activated by the push switches in between the upper and lower keyboards.

That then is the GX-1 made easy. The sounds obtainable are really fantastic and I must say it's worth the money (you do get a rather nice amplification set-up thrown in with it as well). This is, as far as I have seen, the best polyphonic synthesiser around at the moment. It records well and, if you can get over the weight problem, is easy enough to control to play live.

In contrast, but as important in its own right, is the Korg Micro-Preset. This is, as the name implies, a preset monophonic synthesiser. It has a two and a half octave keyboard, a 'simple to use' set of controls and is housed in a teak veneered case that is very light. The whole instrument is so light, in fact, that you could easily hang one round your neck and play it with little discomfort.

The Micro-Preset is a one oscillator synthesiser, the presets selected by a rotary switch/pushswitch matrix system. The six push switches select synth 1, synth 2, brass, string, wood and voice. The rotary switch normally sets the pitch of the voicing, but on synth 2 the 4' and 16' positions are used to give white and pink noise respectively. The pushbutton voices are reasonably accurate in their imitation of various acoustic instruments, though of course you could easily tell them from the real thing and the labels given to each voice should only be taken as a guideline, as is the case with most electronic musical instruments. The synth 1 and 2 voices are similar, although synth 1 will not sustain while the note is held, but dies away (in other words it is a percussive preset, similar in envelope to a piano).

Other controls incorporated in the instrument include attack and sustain controls to alter the envelope of the note, a volume and pitch control, modulation and modulation-routing controls, portamento controls, and a traveller (or filter) control. These are all useful and effective and contribute considerably to the instrument's versatility.

I like this instrument. It is cheap, but it has been well designed and, at the price, is very versatile. My personal favourite effect is a 'laugh' obtained by using portamento on the tenor preset.

Obviously these two instruments are aimed at different ends of the market: the Micro-Preset is a fine instrument for someone wanting to start off in the synthesiser field, and the GX-1 is a good one to end up on. It is, however, worth bearing in mind that you could buy around 170 Micro-Presets for the cost of one GX-1.

rrp: GX1 £50000/$50000
rrp: Korg £291.67/$550

Dave Crombie is resident electronic design engineer at Rod Argent's professional keyboard store in central London.