MATRIXSYNTH: Ellitone Osage Modular Synthesizer System (EOMSS) Serial# 001

Tuesday, November 08, 2022

Ellitone Osage Modular Synthesizer System (EOMSS) Serial# 001

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video upload by ellitone instruments

"audio demonstration of EOMSS serial# 001. this system is now for sale on reverb"

via this auction

"Welcome to the Ellitone Osage Modular Synthesizer System (EOMSS).

This listing is for system serial #001

'analog where it matters, digital where it counts'

Todays listing is for an EOMSS 4-voice starter system:

1x midi to cv interface and stereo mixer module
2x dual oscillator dual wavefolder modules
1x quad envelope quad vca module

the 4-voice starter system contains the essential modular functionalities necessary to achieve four independent analog voices (polyphonic) controlled via usb midi


-EOMSS is a synthesizer format consisting of unique module dimensions, power distribution, audio signal levels, control voltage levels, and connection jack styles. I will attempt to answer most compatibility questions with these quick stats:

-module dimensions: 164mm X 93mm

-audio signal levels: 4v peak to peak (-2v/+2v)

-control voltage levels: 0-10V

-oscillator pitch tracking: 1v/oct

-connections: control voltages (banana jack) audio inputs/outputs (3.5mm mono)

-usb midi in


-includes case power module, 5 pin power cable, 12v meanwell wall adapter
-does NOT include banana cables or 3.5mm mono audio cables.



-incoming usb midi messages are converted into polyphonic control voltage outputs for note values, note on/off gates, cc/pitchbend, and velocity data

-select “OSAGE MIDI” as midi output device in your DAW

-use the BUS SELECT and BUS EDIT buttons to assign each of the four busses (A,B,C,D) a midi channel (1-16) and midi cc# (0-99)

-while multiple busses (A,B,C,D) are assigned to the same midi channel, these outputs become polyphonic. Incoming midi note messages will be parsed between the channels, one after the other.

-hold BUS SELECT button for 2 seconds until display reads 'CC' to assign a CC# for each bus. the default value [00] for CC corresponds to the PITCHBEND midi value. Unlike regular CC messages with a resolution of 127 steps, the PITCHBEND midi value has a much higher resolution of 16,384 steps, this is why it is the default selection. Both CC and PITCHBEND values will be output as a control voltage level of (0-10V)

-hold BUS EDIT button for 2 seconds to bring current value on display back to its default value. a simple trick to save time.

-the stereo panning audio mixer section offers four high quality, digitally controlled analog channels of audio input and summing. some might consider it an overkill to use a specialized quad VCA chip, controlled by DACs and microcontroller to achieve a simple four channel audio mixer. But this approach was necessary to achieve true channel separation and avoid audio bleed between channels. This approach also allows for direct control of channel volumes by incoming velocity midi data.

-MIDI VELOCITY ENABLE button while active will override the positions of the audio level sliders and set channel volumes according to values of incoming velocity midi data.



-two high quality vintage analog oscillator designs based on the classic buchla 258 circuit, each with its own dedicated wavefolder based on the buchla 259 timbre section.

-the 258 circuit was chosen because of its rich wave shapes and excellent audio fm characteristics. These oscillators offer tonalities ranging from sweet and subtle sine waves to absolute chaotic noise
-oscillators are calibrated to track pitch at 1v/oct

-the dedicated wavefolder circuit on each oscillator takes the triangle waveform output and transforms it into a harmonically rich and complex variable wave shape controlled by knob or cv input

each oscillator has three audio outputs:

-(left osc) sine to square. (right osc) sine to saw


-wavefolded triangle out

-oscillator frequency, wavefold amount, and wave shape are all voltage controllable with an input range of 0-10V

-by default, the audio fm input jacks on each oscillator are normalized into the wavefolder output of the oscillator next to it. By increasing the audio fm level knobs, the oscillators will begin to cross modulate each other resulting in subtle harmonic distortions at low levels and spats of blistering noise at higher levels. Plugging another audio source into the audio fm input jacks will disconnect the default cross mod connection.



-four voltage controlled amplifier channels are controlled by four internal envelope generators.

-each of the four channels consist of an audio input, audio output, envelope gate input, envelope cv output (0-10V)

-select which channel to edit using the channel select button. While a channel is selected, its envelope attack time, decay time, and vca offset values are displayed as a ring of lights circling each of the encoder knobs.

-pressing the channel select button until the fifth position will activate all four channel lights. This mode indicates that all four channels of envelope settings are now being adjusted. This poly mode allows for easy editing of all envelopes at once during a multi-voice performance.

-adjusting vca offset affects the shape of the envelope giving it a trapezoid type shape. a surprising amount of useful envelopes can be achieved using these three simple controls.


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