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Wersimatic CX1

Wersimatic CX1.

Wersi have been supplying modular electronic organs for over ten years now. From the outset, the object was to design and manufacture circuits which could be successfully assembled by the home constructor to produce a professional quality instrument.

To prevent the customers finished unit becoming obsolete as new advanced circuitry was developed, Wersi make all new additions or conversions compatible with their earlier models.

The new Wersimatic CX1 is such a development which can be used to replace current Wersimatics or is available as a 'stand-alone' unit with an integral keyboard. Basically it is intended to be a complete, computer controlled, rhythm and auto accompaniment unit.

The instrument circuitry can provide percussive voicing, bass chords and arpeggios. The percussive voices for rhythm are: Bass drum, Snare, Hi-hat (long and short), Cymbal, Tambourine, Brushes, Maracas, Cowbell, Claves and Synthedrum. Bass can be any one of three voices; Guitar, Tuba and Synthesised Bass. Chords can have Electric piano, Guitar, Wah Guitar, Strings or Organ voicing, complemented with arpeggios of Brass, Clarinet, Banjo, Bells or Strings.

The front panel of the stand-alone CX1 is split into two sections; one for instrument programming/playing, the other for rhythm selection and control functions. Two dual-concentric knobs are provided on the control panel for tempo fine/course and volume/balance adjust. A four digit LED display in the top right hand corner of the unit can be used to display tempo (BPM), tuning of the accompaniment section (A-440) and programming location along a measure. The downbeat is also displayed, when running, with a four segment square on the fourth digit.

Each switch on the panel has a built-in LED showing exactly the machine status during programming.

Instrument programming panel.


In total 48 rhythms of 32 beats are provided. The first 32 of these are factory preset, but the last 16 are user programmable. These are selected by pressing one of the 16 rhythm keys and one of the 4 rhythm banks: 1, 2, 3 or Composer. The selected rhythm is loaded intoa buffer memory which allows it to be edited and then stored if required as another rhythm in the composer bank. Intro's and breaks each of 16 beats are also available for each rhythm and can be brought in at any time.

A rhythm can be programmed in two ways; Dynamic and Static. The 'Dynamic' mode allows the rhythms to be entered in realtime with a metronome guide, entries being made on the instrument programming panel. A roll can be produced for any voice by pressing 'Roll' and the instrument. Beats can be erased by pressing 'Erase' and the required voice.

The 'Static' mode allows entries to be made step-by-step in beat/rest fashion, from a score. A combination of these can be used to program a shorter bar for complex timing by entering the Bass in Static mode and pressing End Set at the required position. The other instruments can now be added in the Dynamic mode with the shorter bar length.

Level dynamics are only provided for Bass and Snare programmed by using a '+' for loud and a '-' for soft.

Up to 16 sequences of 32 rhythms can be preprogrammed and stored using the 16 rhythm keys in the sequence mode. A 'Super Sequence' mode can be used during playing which runs through all of the stored sequences (which could be up to 512 bars) lasting possibly 20-30 minutes.

The tempo is also stored for all of the 48 rhythms.


The accompaniment section can also be programmed to complement the rhythms.

A similar memory arrangement applies; the first 32 are factory preset and the remaining 16 user programmable.

Bass, Chord and Arpeggio information is entered via the instrument panel with the notes entered from the lower manual of an organ or, in the case of the stand-alone unit, the built-in keyboard.

CX1 control panel.

Memory Storage

All of the programmed information; rhythms, accompaniment, tempo and sequences can be saved or loaded on cassette. Wersi do, in fact, supply tapes to assist the user create his own library. A 'check' function allows the load to be verified. The memory also has battery back up which allows user programmed rhythms to be retained when the power is switched off.


Wersi have spent many years perfecting their voice cards. The instruments provided are preset, as is the stereo panning, but the sounds are certainly convincing.

The instrument programming panel can be 'played' when the unit is running which allows extra percussion to be inserted between the programmed beats.


The circuitry for the CX1 under review was fitted into a Wersi Comet organ, as shown in the photograph.

All the circuitry is mounted on eight PCB's which slide into a mother board.

The microprocessor is a Z80 which is used to control analogue percussion voices and standard organ type generators for the accompaniment.

In the Comet version of the CX1 the panel was split into two sections; the control panel to the right of the lower manual and the instrument programming panel which protrudes from beneath the organ body on the far left (allowing 'live' left handed additions to the programs).

The stand alone unit differs from the organ version by the inclusion of a power supply, an integral keyboard, tuning control and two switches which allow minor and seventh auto chords to be selected, all housed in a very attractive case.

The CX1 circuitry fitted to the Wersi Comet.


The CX1 certainly offers a comprehensive range of accompaniment. Complex sequences of rhythms, bass, chord and arpeggios can be programmed with ease due to the power of the internal processor. The preset rhythms provide a useful library with which new rhythms can be created and stored in composer memory or dumped onto tape.

The voicing is varied and comprehensive complementing the rest of the Wersi range. Indeed, the quality of Wersi kits is extremely high. All of the circuitry is held in a card rack with gold-plated connectors and the wiring is supplied in pre-formed looms ready for connection.

The kit price of the CX1 circuitry which can be fitted to an existing organ varies between £527 and £627 depending upon the host model, while the stand alone unit, also available as a kit, comes at £1,177 or ready built at £1,782 including VAT.

For further details contact Arthur Griffiths of Aura Sounds, (Contact Details). Please mention E&MM when doing so.

Previous Article in this issue

Godwin Drummaker 32P

Next article in this issue

Mattel Synsonics

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


Electronics & Music Maker - Feb 1983

Drum Machine Supplement

Gear in this article:

Drum Machine > Wersi > Wersimatic CX1

Gear Tags:

Analog Drums

Previous article in this issue:

> Godwin Drummaker 32P

Next article in this issue:

> Mattel Synsonics

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