Expander Modules, Part III

Connecting a preowned, late model Allen MDS-Expander II voice module to play through any make or model of MIDI-capable hybrid pipe/electronic or all-electronic organ console can a valuable complement to the basic instrument's sound.

This is a stand alone unit, either table top (photo) or drawer-type, from an earlier generation made to MIDI-operate through any of the console's bottom manuals up to 3 at a time (Swell, Great, Choir/Positiv) and Pedal.  Its MIDI IN jack connects with the console's MIDI OUT jack via a conventional MIDI cable, and its RCA output jacks send signal via any conventional garden-variety audio cable to whatever amplifier/mixer is in use to power the instrument's speaker system.  The unit comes with its own switching power supply [black brick] which ends on one end in a conventional 3-prong electrical plug [for the surge bar, or power strip] and on the other end in a 9-pin plug [for the module's rear power jack].  Its MIDI THRU jack also might be used to send unaltered MIDI information directly from the console to operate any second expander module, should that be desired.    

The module's 99 onboard voices include classic organ stops -- flutes, strings, chorus reeds, ancient reeds, mixtures, mutations, theatre organ ranks, percussions, and a variety of orchestral and other keyboard instruments.  Up to 4 of its voices may be accessed at any one time, and these may be apportioned to the manuals and pedals in any arrangement desired whether loaded on one division or spread around.  The module also comes with 60 presets which assign various voices to different divisions which may be altered by the player or restored afterwards to original factory configuration.

Most consoles these days are provided with built-in rocker tablets controlling MIDI functions.  Any of the Allen voices may be assigned to these divisional rocker tablets which may then be brought on or off with hand-registering or captured and stored on any of the organ's general or divisional combinational pistons to play either singly or with the instrument's own stops.  The module also may be tuned up or down to sound slightly sharp or flat to the tuning of the host instrument up to 100 Cents, or a full chromatic semitone, in either direction.  Since the ear will tolerate a little sharpness but not the same degree of flatness, setting the tuning of the module barely sharp [up to 5 Cents] adds realism by simulating the random effect of real pipe ranks which are never perfectly in tune with each other.  This results whether all the Allen voices are combined with the full organ, incorporated into all the mid-level ensembles involved in the buildup, or singly with any single stop of the host instrument [which is to say, played as a pair for additional color].

Like many other add-on audio devices including reverb engines, the Allen MDS-Expander II does not have an on/off switch and requires its power supply to be connected/disconnected each time it's in use.  A way to get around this is to simply keep the power supply connected all the time and use the switch on the surge bar that supplies its power to turn the unit on and off. 

Necessity is the mother of invention, and, if the Allen module is a table top model (photo), the top of a stop jamb happens to be the only possibility for placement at the console, and the Allen's rear cable connections won't clear without being elevated a couple of inches, one satisfactory way to get around this is to place the Allen atop a square piece of green flora-foam cut to the correct size (For photo, see main menu, Videos, The Viscount Organ subpage, then scroll to bottom).  Besides being stronger than and superior to conventional styrofoam the color of this material blends visually with the module's green display screen.

If the module to be connected is drawer-type however, and the console already happens to have a built-in right-side drawer that leaves no room for the Allen, the latter can still be operated within reach of the player by leaving its drawer in open position and setting it atop a small but level, rectangular, portable wooden tray placed very close to and about 3 inches below the right side of the bench.      

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