The Eko EM10 is a portable keyboard with a built-in loudspeaker and a choice of mains or battery power supply. It offers ten preset voices (all fully polyphonic) and a pre-programmed rhythm machine featuring 12 factory-set rhythms. Automatic accompaniment over the first octave-and-a-half is also provided, but by far the most interesting feature of the instrument is the programmable chord memory.

First things first, though. The keyboard is 49 notes C to C, and is closer in feel to, say, a typical organ than to a traditional acoustic piano. It's housed in a brown plastic case which is both lightweight and durable, the speaker being built-in to the left-hand side of the keyboard.

To the right of the speaker housing are four slider pots controlling from left to right, master volume, rhythm and accompaniment volume, and sustain level. Some way to the right of these are no fewer than 25 push-switches. These are produced from some sort of rubber compound and are a little fiddly to use at first, particularly as those switches without LED indicators have no other means of showing the user which position they are in. A fifth slider control is located at the extreme right of the unit and controls rhythm machine tempo.

Voices

The 10 preset voices are selected using five of the aforementioned push-switches, a sixth being used to select the remaining six voices. Below is a subjective appraisal of the sound of each preset.

Piano - A good electric piano sound, particularly effective with a touch of sustain, though it's at its best over the last 1½ octaves, the bass end suffering a little from distortion. (The EM10's memory reverts to the piano preset automatically when switched off).

Harpsichord - Not terribly harpsichord-like, but still a useful poly sound, with a powerful bass end, sparkling top and a minimum of distortion.

Guitar - A fair attempt at a 'plucked-string' sound, again with a powerful bass end, though the quick attack doesn't quite come off further up the keyboard.

Musette - A pleasant, accordion-type sound, though it's a pity the deep vibrato isn't in some way controllable.

Pipe Organ - Excellent rendition of a big church hall diapason, the top-end is particularly striking. This is a sound a lot of manufacturers get wrong - well done, Eko.

Strings - A bit disappointing, with a rapid instead of slow attack, and a non-switchable delayed vibrato. Too metallic to be really convincing, it might nonetheless serve as an interesting woodwind alternative.

Clarinet - As Pipe Organ, only one octave down. Very clean and pure.

Brass - Another variation on the organ theme, though this one suffers a little by comparison due to some distortion when the first two octaves are used in conjunction with mild sustain.

Vibes - Best sound on the keyboard. A convincing percussive envelope makes it equally usable at either end of the keyboard, while a little sustain makes it more impressive still.

Jazz Organ - A reasonable attempt at imitating a Hammond though don't expect miracles on a machine of this size and price. Percussive attack and vibrato a little on the heavy side, but nonetheless quite usable.

Once you've selected your preset voice (only one voice at a time can be used) you're then faced with a bewildering selection of operational modes from which to choose. First off, the EM10 can be played as a conventional keyboard, ie. with none of the switches in the 'automatic' section activated. Alternatively, the 'split' tab can be used to divide the keyboard into two, the first nineteen keys forming the 'accompaniment' section, the remainder forming the 'solo' one.

The 'manual chords' button (automatically activated when the unit is switched on) enables you to form chords in the accompaniment section in the normal way, but if your left hand is feeling a little lazy, the 'OFC' (One Finger Chord) switch enables you to form four types of chords using just one (or three) fingers. The chords are major and minor triads and major and minor sevenths, and using them is simplicity itself: all you do is play any white note in the accompaniment section to form a major triad, adding any higher black note to form a minor one. Similarly, seventh chords are formed by playing two white notes simultaneously, while adding a higher black note to this arrangement will give you the corresponding minor seventh chord.

Auto Functions

Once you've selected your one-finger chords, the 'Auto Combined Chords' switch will provide a suitable arpeggio for the accompaniment section. This facility also operates with manual chords. For the solo section, a separate (non-programmable) arpeggiator comes into play when the (surprise, surprise) 'Arpeggio' button is activated, though like the 'Auto Combined Chords' facility, this only works when the rhythm machine is in use.

The most spectacular facility offered by the EM10, however, is the chord sequencer. This device can memorise and subsequently play back automatically an accompaniment up to 255 chords or rests in length, although unfortunately the memory can only store the factory-preset one-finger chords described above.

First step when programming a chord sequence is to press the tab marked 'record', whereupon the memory will be activated and will store any one-finger chord you play. Note however that, like most of the other auto functions present on the EM10, the chord sequencer can only be used with the rhythm unit in operation.

For programming, the last four white notes and last black note on the keyboard act as chord sequencer controls. Essentially, the system works like this. Once you've decided on the chord(s), the duration of each chord in bars must also be decided. If the duration is to be half a bar, the 'B' key is pressed while the one-finger chord is held down. For chords of one bar duration, the procedure is identical except that the 'B' key is substituted by the 'C' key, while chords of two bars or more duration use the same key pressed once for each bar required. These two keys are marked with a crotchet and a minim respectively making identification easy.

The above procedure is used for rhythms in 2/4 time but differs only in detail for other rhythms, these details being comprehensively covered in the users' manual.

To programme a rest, all you do is hold down the 'B' or 'C' keys (whichever is appropriate) without any chord being played in the accompaniment section. The B-flat key (marked 'loop') can be activated at the end of your sequence, thereby enabling the program to repeat itself automatically each time it ends. If you don't require this facility, it's advisable in practice to programme a few rests at the end of each new sequence in order to erase any chords that may still be in the memory from a previous program.

Playback

Replaying the programmed sequence is simplicity itself, as it only requires pressing the 'play' and 'start/stop' buttons. Unfortunately, the chord sequencer cannot carry on where it left off, ie. if you stop the sequencer and start it up again, the programmed accompaniment will start again from the beginning.

It's still a useful and easy-to-use sequencer though, as correcting errors is a piece of cake (using the 'G' key, marked 'Amend') and a couple of rests is all you need to separate one programmed sequence from another.

In sum, the Eko EM10 is an interesting addition to the portable keyboard market, with some good preset voices and a chord sequencer that makes user-programmed accompaniments a doddle. At the price, I would like to have seen a slightly more sophisticated rhythm machine (with a selection of factory-set fill-ins, for instance) and perhaps a keyboard with a little more 'feel', but these are relatively minor quibbles, and the EM10 should find use as an educational tool as well as a 'fun' keyboard just about anybody can use.

The Eko EM 10 has a recommended retail price of £299, and further information is obtainable from the importers, John Hornby Skewes, (Contact Details).