Leto Atreides recants and discovers a new affinity with Korg's new EX800 Expander.

Your humble author lies on the chopping block, jugular exposed, waiting for the axe to strike. For in sooth hath he spoken evil things of the Korg Poly 800, and yet here he stands, about to enthuse at length on its offspring, the EX800 Expander. How can such things be? Read on, and all will become clear.

The Poly 800, although a worthy little synth in many respects, doesn't seem to have caught the public imagination as Korg had hoped, as evidenced by much discounting in the retail stores. It offers many valuable facilities — 8-note polyphony, a built-in poly sequencer, enormous portability and MIDI, but is let down by one or two drastic mistakes — a single filter (which takes it back to the days of string ensembles) and the fact that the battery power option gives you only a couple of hours playing and then proceeds to wipe all your sequences and patch memories when the batteries die. Nasty.

Now you may expect that an expander version of the 800 — having most of the facilities but no keyboard — would be a nonstarter, but the very opposite is true. The EX800 is QUITE WONDERFUL, and can offer really excellent value for money for anybody who can make it part of a MIDI polyphonic system.

Specs on

Let's quickly look at the specification of the EX800, keeping in mind that it's virtually identical to that of the Poly 800. The module plays 8-note polyphonically with a single bank of oscillators plus chorus, with an option of 4-note polyphony with layered oscillators for thicker sounds. Apart from the eight oscillators there are three digital envelope generators with six stages each (DEG2 is only operational on the second bank of oscillators in layered mode) with the last DEG controlling the filter and the white noise. Having Noise controlled separately from the oscillators can be very expressive, and by far the most impressive of the 64 preset sounds is an incredible flute with a chiff of overblown noise at the start.

Unusually, it's possible to add in any combination of footages on the oscillators — 16', 8' 4' and 2' — and all the usual bonuses like filter track on the keyboard, reversible polarity on the filter envelope and delayed modulation are there. To help make up for the single filter it's possible to choose single or multiple triggering to decide whether a new note will retrigger the filter on previously held notes or not. Additionally there are four parameters referring to MIDI and sequencer control, of which more later.

The sequencer is simple but powerful. Just enable it with a back panel switch, enter notes singly or in chords, and it'll play them back in step time clocked by a front panel control or MIDI input. This system gives a nice compromise between simplicity and musicality, allowing more complex patterns if you insert a few rests — total capacity is over 200 notes. The main problem is that the sequencer output doesn't appear at the MIDI sockets, so you can't control other synths with it.

Unlike other expanders, it's possible to alter the sounds in the EX800 using nothing more than a pair of front panel +/- buttons. Apart from these there are only eight other controls plus an eight-figure keypad. They are as follows — Write (for programming in new presets), Program/Parameter (to decide whether you're selecting a new sound or a new parameter to edit), Sequencer Start/Stop, Speed and Step, Tune, Power/Volume, and Bank Hold (which restricts program changes to one of the eight banks).

Punching in two numbers gives you a new sound in Program Mode or a new parameter in parameter Mode (easy isn’t it?), and in the latter mode the +/- buttons will alter the filter setting, envelope times or whatever. In the case of some parameters there are only two or three possible settings — Chorus On or Off (one or two), Octave High, Mid or Low (one, two or three), but for Filter and other important settings there are 16, 32, 64 or 100 settings. Holding the + or— button spins through the possible settings rapidly, so it doesn’t take too long to call up parameters, alter and store a new sound.

Now all this is familiar from the Poly 800, as are most of the back panel sockets — 9V power (transformer supplied), Headphones, Left/Mono and Right Audio Out, Program and Sequencer Write Disable/Enable switches, From Tape High/Low, To Tape Enable/Disable, Program Step Footswitch Socket (wraps around from 88 to 11), and MIDI In/Out (Thru too on production models). So why is the EX800 a better bet than the Poly 800?

VFM

Quite simply, it's a question of value for money. At around £350 you know exactly what you're getting with the EX — a MIDI expander which has to be controlled from another keyboard, from a MIDI computer link or from a sequencer of some kind. You don't have to agonise as to whether a single filter is enough — it's pretty clear that the EX is a great additional layer to an existing synth with keyboard rather than a synth by itself. There's none of this portable keyboard and flat batteries nonsense — no stacking up piles of synthesisers to enable you to do multitrack MIDI composing. The EX800 sits neatly out of the way — in a 19" rack using the flanges provided if you like — and gets on with the business of producing sounds while you get on with the playing — on only one keyboard for as many expanders as you desire.

So apart from doubling up sounds on existing synths, perhaps providing a little analogue twang to contrast with a DX7's metallic precision, the EX could best be suited to complex MIDI composition. This is where the programmable MIDI functions come in; you can reprogram the module's MIDI Receive Channel from 1—16, select Internal or MIDI clocking of the sequencer, decide whether patch changes can be made from external controllers (taking Korg's peculiar notation of 64 patches from 11 to 88 into account) and decide external pitch bend depth. The EX doesn't have MIDI Mono Mode, so it can't make more than one sound at a time, nor can it react to velocity information (the "Active Sensing" which has confused so many is simply an addition to the original MIDI spec which makes sure an input is present every so often). However, it is ideally suited to use with Korg's new portable MIDI "poser's keyboard", which can even alter its volume remotely as well as making patch changes.

You can MIDI dump patch information between Poly 800s and EX800s using the MIDI System Specific protocols and can happily use the EX800 with any of the existing computer-based or stand-alone MIDI sequencers. Using a package such as SIEL's polyphonic Composer, you could enter notes on the computer keyboard and play back on to six or more Expanders, so avoiding the need ever to look at black and white keys again!

The Expander's preset sounds predictably benefit from a few minutes' modification (except that flute!) and it's possible to get reasonably thick, twangy, almost Prophet-like textures, although you'll always find yourself using the mixing desk to give them a little added power. Strings and brass are no problem, and because of the multiplicity and complexity of envelopes it's possible to produce some complex, slowly-developing layered sounds untypical of other synths as well as helicopters, funk basses and much more; there's no Unison mode for powerful lead sounds though.

Not that the EX800 isn't exotic, but in an increasingly MIDI-dominated market it's hit the nail on the head, ironically much more accurately than the Poly 800 ever did. However, it's bound to rekindle interest in the Poly 800 and to become the centre of many inexpensive MIDI modular composing systems, as well as acting as a value-for-money add-on sound module. A very hearty pat on the back for Korg — now for a Poly 61 expander...