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Lowrey MX-1 Instrument Review

Article from Electronics & Music Maker, May 1981

Each month we review the latest Electro-Music Equipment — from synthesisers to sound reproduction and effects! E&MM's special in-depth reviews look at what's new in the world of commercial music — a vital updating for both electronics designers and musicians.

Lowrey MX-1 Electronic Organ

It seems a definite turning point has now been reached in the marriage of organ, synthesiser and computer. No longer does the organ aficionado, whether amateur or professional, have to take a less than perfect reproduction of an instrument. The developments in micro-technology can now make possible the duplication of traditional orchestral and popular music instruments so that it is difficult to know which is the original. I must be one of many people who watched the BBC TV 'Parkinson' show recently and literally couldn't believe that the sounds I was hearing came from one single instrument — the Lowrey MX-1. It was expertly played by Harry Stoneham, although I doubt whether even he needed to concentrate all his skills to make the instrument create an electronic orchestral sound of such complexity. In fact, all you've got to do is play a single 3-note chord on the lower manual and select your orchestral combination, from Big Band to Baroque, and away you go! And it's not just the realism of the instrument voices, it's the way each instrument plays counterpoints, harmonies and rhythms ideally suited to it.

All this and much more is achieved at a price — the MX-1 costs £13,950 — although Lowrey have already introduced a new range of 'Micro-Magic' organs, starting with the Fiesta at £855, that no doubt benefit from this new technology.

Back cover removed showing first layer of circuitry.

The conception of this remarkable instrument first started about five years ago in Chicago, Illinois at the Lowrey Organ Division of Norlin Music Inc. It first emerged in the UK at last year's music trade fair, having been on sale in America for a year, and the reception it received was tremendous — we all looked for the hidden tape recorder with no success! Certainly, the implementation of a huge amount of micro-chip circuitry in one home organ cabinet has created a system that could well be come the ultimate dream for many home organists — but no doubt there are more innovations to come. Many of the ICs are custom LSI chips developed by Lowrey — for example, there's the Serial Interface Controller which is virtually a microprocessor in itself.

I spoke to Braham Digdgelli, Service Manager for Lowrey U.K. at Braintree, Essex, and he commented that although the design was wholly done in America, he is able to provide feedback from the British point of view. Braham then proceeded to give me an enthusiastic survey of the MX-1 that took no less than three hours!

Controls and layout

We switched on and immediately the organ jumped into a routine of flickering lights reminiscent of Star Trek's instrument panels! In fact the tabs, pedals and obviously the presets, which all have coloured LEDs under their buttons, are scanned one by one every 5 microseconds to show that the organ is operating properly and waiting for your command. The moment you select any button the effect is cancelled. The majority of the controls operate through a 'PIC' — Parallel Interface Controller which enables, for example, tabs to switch FETs and similarly gate all the other hardware that the performer uses to the organ microprocessor.

The control panel is illuminated by two side halogen spotlights that can be directed onto the controls or music rest at two intensities. There are tab lights, pedal and panel lights (high and low brightness) as well. Lowrey sliders, introduced about 2 years ago, are smaller than standard constructors sliders and felt as smooth as they should be and the small single touch 'latching' presets contain a special low current LED that can change colour on certain functions (from red to yellow or green) thus indicating a change of mode. This is especially useful on the Digital Stereo Rhythm to indicate end of intros.

A low impedance stereo headphone socket is provided, if you don't want to deafen your neighbours with the MX-1's 6 x 40 watt amplifier system. An interesting extra, that should be on all drum machines these days is a 3-digit LED readout of tempo for setting the rhythms which subsequently synchronise all the 'Orchestration Plus' accompaniments, 'Magic Genie' chords and 'Golden Harp' arpeggios. The control slider is not a 'pot' type but a multiple switch, so that the numbers indicated step from 54, 59, 64 in exponential fashion to 295, 321, 350 and 380 maximum tempo — no more guessing the correct speed from Rock to Waltz!

All controls are situated on the main front console and this includes external phono sockets in and out for stereo recording of the organ or playback of taped music. Another big advantage here is that the 'Leslie' effect (called Stereophaze Sound) for the organ tabs is very good indeed and is electronically-generated so that it will be present on the recorded signal. The organ speakers can be cancelled if desired and external speakers used instead and there is a 'Cancel' switch that will cut out all accompaniments immediately to give full manual control.


The power supply is quite substantial and provides a range of + and - voltages that draws a surprisingly small primary current of under 1 amp! The keyboards (both 49 note, upper C-C and lower F-F) are fully polyphonic, operating single contacts for diode keying and they are scanned from right to left every 5 microseconds by the Serial Interface Controller. You can even hold virtually all notes of the lower manual on 'Magic Key Memory' without the pitch drifting. Thus 49 upper, 49 lower and 18 pedal switches feed serial data to the Keyboard Encoder which sends its information to the upper manual flutes, Solo Symphonizer, Golden Harp, Orch. Percussion and AOC; lower manual flutes, Magic Memory and Magic Chord. It provides data that selects the fractional flute, on/off strike tone and Orchestral Symphonizer pitches. At this point too, the pedal and lower keyboard serial data goes to the CPU which produces Data and Address lines and Control Bus (WR, Reset) for the Orchestration Plus system. The Magic Chord, AOC and Golden Harp are also controlled via the Keyboard Encoder.

Various triggers, for the EGs, sustain control, strike tone for bells and vibe voices, snub lines (for initial control of piano and other percussive instruments) are initiated from keynotes played. Main tone generation is done by Top Octave Synthesisers (TOS) receiving a 4mHz oscillator and dividing down over the pitch range. Vibrato and Glide (a semitone slide up to the note) is obtained by modulating the oscillator, the latter effect is sometimes inserted automatically on Orchestration Plus, or it can be added manually from a foot button operated by the right toe as it moves the swell pedal. Certain sounds such as 'piano' will change the glide into a 'sustain' control. The selected pitches are sent to the main instrument tone generation boards which include Symphonic Strings, Vibes, Vibra Harp, Violin, Hawaiian Guitar as well as the Orchestration Plus and Solo Symphonizer. The Custom Symphonizer is really a synthesiser with the minimum preset and control slider functions for quick setting up.

It relies on a suitable sound source, taken from Orchestra (Polyphonic) or Solo (Monophonic) before it can produce percussive effects. Wow and rich stereo chorus can be added to get a big solo lead synth sound.

Note the two 6

Many of the voices are derived from several tone formants that are a result of adding pulse waves and sawtooth waves which are then filtered to give instruments like oboe, trumpet, sax, bassoon, and jazz flute. Fractional filtering gives flute pitches of 16' 8' 5⅓' 4' 2⅔' 2' and 1' and low frequency sawtooth waves also control attack and decay on filters to give more realistic sounds. Tremolo can also be added to both Orchestral and Solo Symphonizer, which is really a BBD generated chorus effect giving pitch and volume variation after a slight delay. The result is a much more natural modulation on most instruments especially 'wind' types. It's nice to see a tuning control for each of these sections so that synthesiser style detuning can be done. Incidentally, instruments have their tonal qualities altered as you play each group of 7 notes up the keyboard, thus acting like a keyboard follower to brighten higher pitches.

The Solo Symphoniser plays on the highest note of the upper manual and has Piano, Clavecin, Rock Guitar, Sax, Oboe, Jazz Flute, Jazz Guitar, Clarinet, Bassoon, Trombone and Trumpet instruments. A solo keying on/off button ensures that note jumping does not take place — i.e. from releasing a single top note it will not jump to a lower pitched left-hand chord, which can be very irritating with both hands on the one manual. The large Solo generator chip gives 16' 8' 4' and 2' squarewave outputs and these go through their own Solo filter board containing analogue switched filters for multiple selection during the actual instrument envelopes. The Jazz Flute is a good example with a 4' initial envelope and noise 'breath' added to the 8' pitch. The noise generator is digitally produced from the Rhythm board.

The Rhythm system is operated from another PIC which keys 15V op-amps, providing suitable triggers for each percussion effect. The main sounds are bongo, bass drum, cymbal, tom-tom, wood block, hi-drum, snare, low-drum, clave, and noise (for Jazz Flute treatment). With 'Autostart' on, the drum rhythm selected — there are 16 to choose from including two-tone metronome — will commence as soon as you play one or more notes on the lower manual and the percussion will continue until you release all these notes. It doesn't stop immediately but ends suitably on the first beat of the next bar (that is why there is a period when you can release the chord and move your left hand to play the upper manual or select other tabs, before it is necessary to return to the chord for continuous rhythm — very useful indeed). One of the most interesting developments here is that when a sound is selected on 'Orchestration Plus', the rhythm section will flash those selector buttons that provide the most appropriate rhythms for the sound, so 'Big Band' suggests a choice of Dixie, Country or Samba. Choose one of these and you then have the best combination for the music you are playing. You could, of course override the suggestions by selecting another rhythm — such as 3-beat 'Waltz' with a 4-beat 'Baroque' (Dave Brubeck would like this one!). The 3 beats of the waltz still have the same basic pulse as 4-beat, unlike other drum machines whose beats are divided over 48 parts, (i.e. 3 every 16, and 4 every 12).

Second layer of circuitry revealed.

The drum sounds themselves are extremely authentic and are produced in stereo with a push-button cymbal crash that is derived through its own LSI to give you multiple ringing effects exactly like a big cymbal decaying. There's an 'intro' button that gives a suitable fill-in before all the Orchestration Plus and Magic Genie accompaniments burst forth. You know when the fill-in is finished because the LED downbeat indicator changes colour from red to green, and a 'Rhythm Balance' control sets the L/R speaker outputs for real stereo percussion.

Needless to say, this is where both Braham and myself began to deviate from the circuitry functions towards the musical effects and special controls! So I will simply justify this by saying that we both had realised that the enormous complexity of this instrument can only be briefly discussed in this review — it's the central processing unit based on an 8085 microprocessor, with bi-directional Address/Data bus and control lines for operating an 8 x 1K RAM, SIC 1 Button scan, address latches, SIC 2 Key-switch scan, that masterminds the MX-1. The push-button scanning is performed through the SIC by looking at Y select lines (a vertical row of buttons) and then sending an X-scan to decode which of the horizontal buttons in the vertical group has been selected. The Orchestration Plus boards produce up to 6 different instruments including a bass line from the 'pedal keyer and filter' board for each button selected.

Controls and effects

There are a lot of features on the MX-1 that make it easy for the beginner to get a full accompaniment that is synchronised with the rhythm and other effects. On the other hand, they also increase the possibilities of multi-layer 'orchestral' performances for the more experienced musician.

Orchestral Symphonizer Sound Decoder using PIC 7949.

The 'Magic Genie' chord system gives interesting homophonic accompaniment from Piano, Guitar and Banjo tabs, with auto bass derived from the LH chord played. A LH single note gives a major chord and this is changed to minor from the right toe foot switch on the pedal. This switch also adds Golden Harp when you want it and gives yet another effect for the competent player to master and enjoy. Its extra 'Magic Key Memory' feature is linked to the 'Magic Genie' and 'Orchestration Plus' to allow the player the temporary use of both hands on the upper keyboard to play full block chords.

Orchestral percussion has a distinctive set of percussive instruments: Bells, Vibes, Vibraharp, Chimes (on top 30 notes), plus Accordion, Hawaiian Guitar and Violin. Also here are 4' and harmonics for adding to flute drawbars used on jazz/pop organ playing.

The Golden Harp is great fun to use and will give swirling arpeggios, always synchronised to the rhythm tempo, but selectable for fast, slow, up, down and 'virtuoso' (variations on up/down) arpeggios. It works on the Orchestral Percussion voices (and Orchestral Symphonizer as an option).

CPU board containing PROMs, RAMs and ROMs.

AOC (Automatic Organ Computer) is one of Lowrey's selling features on their organs and it gives full upper keyboard harmony from 1 finger of the right hand. The chord is formed from the lower manual chord being played. AOC 'Organ' provides chords for upper tabs and most of the Orch. Symphonizer voices and polyphonic Custom Symphonizer. In addition, AOC 'Open Harmony' produces a wide two-hand style chord that really does give a full ensemble sound to melodies and can easily convince the listener that a complete woodwind, string or brass section is playing.

The 'Stereophaze Sound' provides a particularly good stereo image for the player from carefully positioned speakers in the console. Here you have the traditional Leslie sound and more, all electronically produced so that recording the 'live' sound is easily done through the Stereo phono output sockets.

It's not a bad idea to use headphones to monitor recording if possible and it's also important to keep the swell pedal volume off maximum otherwise you'll start picking up the usual electronic organ background whistles and noise. In live performance the sound quality is excellent — especially considering that the largest speaker is a 10", for the bass really thumps out if you want and the top is bright enough to do justice to all those high harmonics.

Cymbal processor and drum circuitry.

In all there are two 10" Bass speakers mounted in a central sealed enclosure (see photos), two 6" x 9" Chorus speakers at left and right ends of the console, one 8" main speaker and two 8" flute speakers.

'Vibra Trem Flutes' create the traditional 'chorus' fast rotor effect. Flute and Main Chorus tabs give an ensemble (from a very short pulsed delay treatment on one channel whilst the other side is straight). Chorus, Celeste is really the slow rotor 'chorale' effect. Vibrato, Tremolo (as described) and reverberation can be added to complete the concert hall sounds of the MX-1. There's even a Marimba repeat that gives alternate reiteration from two notes, and of course variable sustain.

Instrument Sections

Now we come to one of the most exciting aspects of this instrument, the vast range of sound combinations available — there's virtually nothing missing (except Harmonica!) and to complete it all comes the innovative 'Orchestration Plus' section.

Orchestration Plus circuitry.

There are Symphonic Strings on upper and lower chorus that have a realistic phased ensemble quality for d. bass, cello, viola and violin. 'Orchestral Symphonizer' gives Grand Piano, Brass Ensemble and specials such as Banjo, Electric Guitar, Post Horn and Mandolin. The Solo Symphonizer complements the latter section for lead-line playing that adds an authentic top-note solo to your right hand, from a reasonable 'reedy' Sax to 'breathy' Jazz Flute, and then you can add the Custom Symphonizer in mono or poly mode as well.

'Symphonic Bass' gives tremendous depth to your own pedal playing — after all, 'piano' on the Bass gives that rich orchestral film score feeling (such as on John Williams' original score for 'Star Wars'). There is Tuba and Bass Fiddle as well, with the 18 note pedal-board a great help for church organ music. And we mustn't forget the full tab selections on upper and lower manuals. These not only include a full flute tab set (except 1' mixtures), but have a custom flute tab that lets you set sliders in any combination just like drawbars. Full brass, clarinet, and a Vox Humana that almost sounds like voices complete the tabs.

Finally, we come to Orchestration Plus, described by Lowrey with a string of superlatives as 'the most advanced, innovative, imaginative, truly incredible musical feature ever to be introduced in an electronic organ'!

There is no doubt that this section provides the most exciting feature for this instrument. Its innovative design enables, for the first time from one instrument, a choice of twelve preprogrammed fully orchestrated accompaniments that are very realistic indeed. Despite the fact that every two or four bars, the selected 'orchestra' repeats its various counterpoints based on lower manual chords (any inversion), the variations of instruments and melodies are sufficient to avoid any feeling of monotony when played properly. With 'Chord-Logic' button on certain chords (in particular the flattened 7th) will make the CPU select a slightly different melodic line, and even give glide on appropriate instruments such as trombone. 'Basic Mode' will give a full set of instrument groups on all chord rhythms. Switch this effect off and you're back to separate sections 'doing their own thing'. 'Variation' ensures that you'll never get tired of the accompaniment! You can also have 'keyed style' so that the orchestra only plays for the duration of a left-hand chord. Needless to say, there are enough couplers and upper/lower select options to give plenty of variations to your registration.

It is at this point that the final say has to be left to the instrument itself! So on E&MM's Demo Cassette No.2 I have provided examples of the Orchestration Plus section, from Big Band and Polka to Waltz and Baroque. Here I'm sure the provision of an aural complement to this review will be worthwhile, for the examples are done not by spending hours of practice to master the controls and effects in a virtuoso way, but by simply sitting at the organ and there and then assessing what the instrument can do without too much effort. Thus you have a more accurate idea of what the home musician can achieve after a very short time (provided he knows his chords and names of controls). Other features are highlighted on the cassette and along with this review should help you assess this unique instrument for yourself. You may need a good few 'strong arm' men to lift the superbly finished console — it weighs 357 lbs (162kg) (there's a matching bench too) and it measures 28¾" (731mm) from front to back. That's just less than many door frames — but I for one would be quite happy to remove my front door to get the MX-1 in my house!

Previous Article in this issue

Electronic Dream Plant Limited

Next article in this issue

Hot Wiring Your Guitar

Publisher: Electronics & Music Maker - Music Maker Publications (UK), Future Publishing.

The current copyright owner/s of this content may differ from the originally published copyright notice.
More details on copyright ownership...


Electronics & Music Maker - May 1981

Gear in this article:

Organ > Lowrey > MX-1

Side A Tracklisting:

09:59 Lowrey MX-1 Organ.
11:34 - Lowrey MX-1 [2]
12:23 - Lowrey MX-1 [3]
13:24 - Lowrey MX-1 [4]
14:24 - Lowrey MX-1 [5]
15:36 - Lowrey MX-1 [6]
16:54 - Lowrey MX-1 [7]
17:24 - Lowrey MX-1 [8]
19:05 - Lowrey MX-1 [9]
19:45 - Lowrey MX-1 [10]
21:15 - Lowrey MX-1 [11]
22:52 - Lowrey MX-1 [12]
23:35 - Lowrey MX-1 [13]

E&MM Cassette #2 provided by Pete Shales, digitised by Mike Gorman.


Previous article in this issue:

> Electronic Dream Plant Limit...

Next article in this issue:

> Hot Wiring Your Guitar

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