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eowave Quadrantid Swarm

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The Quadrantid Swarm is a desktop touch synthesizer aimed at sound designers and musicians who are looking for an expressive tool to explore rich and unusual soundscapes with a direct intuitive approach.

Past research and development at eowave has contributed to a range of successful products aimed at musicians and performers - including sensor interfaces, MIDI devices, modular synthesizers and more. This has been honed and distilled in the Quadrantid Swarm. It is an instrument that has been designed openly - to be used with MIDI, alongside your modular synthesizer/CV sequencer or to be explored as a standalone drone/sequencer/generative synthesizer.

Here is the first protoype being presented at Superbooth'17 (many features have been adapted between then and the production model!)


The QS now features 8 modes. Each should be considered a springboard for musical exploration, rather than a preset. The modes are not direct emulations of existing instruments, but they borrow on inspiration from their namesakes. We found that this was the best way to retain the immediacy of function per button design while offering a generous feature set. The QS will ship with a cheat sheet that details the specifics behind each mode - the waveform, perc sound and character effect.

Front panel

Building on the feedback we received at Superbooth 17, we have redesigned the front panel to be easier to read. This matte black PCB pictured below is the final material we will be using on production, although there is a mistake on this panel that will be rectified (white layer inverted!).


The oscillator section is a digital wave generator. In sequencer mode the spread control multiplies the waveform up to 8 waveforms. In keyboard mode the spread control will not affect the oscillator because the 8 waveforms are spread across the touch keyboard to be used as a simple polyphonic synthesizer. Character controls a different effect or folder depending on the mode. The character effects/folders will help you design timbres that will range from clean and glassy to dense and distorted. To change between sequencer and keyboard mode, hold shift and press start.

CV IN - control voltage input from eurorack or analogue sequencers
mod - attenuation for CV in
freq - frequency (to tune the oscillator with your other devices)
spread - in sequencer mode this controls the spread of the 8 triangle waves, in live mode this is inactive
character - amount of wave folder or effect
What else...? We have also added in a sine wave which isn't processed through the spread or folder, giving an extra layer to your sound design


Tied to the fundamental frequency of the main oscillator is a percussive element. The type of synthesis implemented is different for each mode.

perc - decay length

A simpler mixer section, feeding into the two filters directly below, comprises of three inputs. One for the oscillator voice, one for the perc voice, and one spare. The spare input can be used to patch in an external signal, utilising the filters. With nothing patched in, the third input is pre-patched as a feedback for the spring reverb (which will overdrive/distort with high gain levels to great effect).

voice vol - oscillator voice volume
perc vol - percussion element volume
IN - channel 3 input jack
in vol - channel 3 input volume/pre-patched to spring reverb feedback


Two analogue 12db filters, based on our 'fluctuations magnétiques' module. Filter 1 can be switched between high or low pass. Filter 2 is low pass. Using the two filter poles together you can create a bandpass and other interesting filter shapes. This allows for rich, throaty and deep sound sculpting.

cutoff - cutoff frequency
mod - modulation attenuator
MOD - modulation input
res - resonance amount
hi/low - high pass/low pass switch


Two modulation sources unlock the expressivity of the synth. The first is an envelope, pre-patched to the cutoff on filter 1, and also patched to the VCA. The LFO section is pre-patched to the cutoff of filter 2 and features seven selectable waveforms via the shape function, and an 8th mode which is the sequencer CV out (allowing the sequencer to be patched to other devices). Speed is set using the speed knob. A square output has been included which can be useful for triggering clock resets and other timing functions. A slew in, out and attenuator has also been implemented to further your modulation experiments.


GATE - gate input
attack - attack length
release - release length
ENV - envelope out (pre-patched to MOD of filter 1)

triangle shape - LFO main output, LFO shape changes as per selection (pre-patched to MOD of filter 2)
square shape - square output which remains square regardless of shape selection
speed - LFO speed or frequency
shape - select one of seven LFO shapes or sequencer CV out
NOISE - noise output linked to LFO speed. Can be used as audio or modulation source
SLEW IN - slew input
slew - slew amount
SLEW OUT - slew output


An analog spring reverb adds bundles of character to the QS, and can be mixed and used to feedback into itself for chaotic overdrives. The reverb section can be used independently of the synth with your other devices, by patching a cable to REV IN, and using the main output.

rev input - pre-patched to filter out, this is the reverb gain. It will clip at high levels
rev level - reverb amount, higher levels give the impression of a larger space
MOD - modulation input for reverb level
REV IN - you can use the spring reverb of the QS independently with this input

A simple VCA can be patched to the envelope, LFO or external source to amplify the QS.

VCA CV - pre-patched to ENV output
VCA OUT - pre-patched to REV IN
OUT - main mono output to connect to your mixer or audio interface
Interfacing (MIDI, CV and audio inputs)

We will be including a standard MIDI to 3.5mm adaptor to use in your live or home setup. CV, trigger, clock and reset inputs are also featured to use with eurorack standard devices.


We designed the QS for immediate use without having to worry about complex patching, so pre-patching is used to make connections in logical places. Some of these are highlighted using arrows, particularly the modulation sources and connections, the audio routing hasn't been highlighted to keep the design clean, but is explained above.

Capacitive touch keyboard

To select a mode, hold shift and press the desired key. To change between kayboard and sequencer mode press shift and start. In keyboard mode you can play the keys as a traditional keyboard. Pots 1-8 above the keys tune each step. In sequencer mode, press start to begin the sequencer. Now each key acts as a gate on/off, which triggers the envelope. Active gates are represented with a red LED.

Capacitive touch relies on the conductive nature of your body. The keyboard is used in selecting modes, turning on and off sequencer gates and playing the keyboard. Some of the modes also feature pressure sensitivity, allowing for velocity type control of the synthesizer.


The QS has no memory to save settings or sequences. The 8 modes are the only form of memory and cannot be overwritten. It is designed this way - as a tool for sketching, patching, jamming and experimentation. You can of course use your favourite sequencer to send clock, notes and gates over MIDI and CV.

Technical Specifications
Type: Digital
Oscillators: 1
Waveforms: Triangle
Osc Modulation: Knob, LFO
Envelopes: 1
Evelope Paramerters: Attack, Decay
Filters: 2
Types: 12dB Slope (2-pole), High Pass, Low Pass
Filter Modulation: Knob, LFO
LFO: 1
LFO Notes::
+8 waveforms
Polyphony & Tuning
Polyphony: 1
Tuning: Standard
Modes: Mono, Polyphonic
Patches RAM: 1
+8 Step Sequencer
Case: Desktop
Case Details: +8 touch keys
Keyboard: Wood
Controls: Buttons, Knobs, Modulation 1/8" Jacks, Pedal - Filter, Sequencer
Audio Output Connections: 1/8" Phone Jack, Mono Out
Audio Output Count: 1
MIDI Ports: IN
CV Ports: CV IN, Trigger In
Year Released: 2017

Product Links
Company Product Sites:
[+] www.eowave.com
MSRP List Price: 499€ - convert
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References & Sources

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