Archean is an open-source patchable synthesizer.

It is a fully open-source project. Both the firmware and the circuit schematics are openly available, empowering you to modify the code to add new features or change existing ones. The firmware runs on a Teensy 4.0 and is programmable via the Arduino IDE, making it easy to experiment and develop your own functionality.

The oscillator generates sound waves in a range of seven octaves (16.25 Hz to 2093.0 Hz). The synthesizer generates three types of sound waves: the first is a signal in the form of a randomly generated landscape, the second is a constantly and smoothly changing random landscape, and the third is a triangular waveform.

All control voltage inputs and outputs have a voltage range from -5 to +5 volts. The 1 volt per octave input ranges from 0 to 7 volts. The touch keyboard, consisting of various mineral shapes, has 22 keys and adjustable scales, of which there are 22 types.

The synthesizer has two audio outputs: a line output and an output for Eurorack systems. The synthesizer can receive MIDI messages via USB, through the MIDI input, or be controlled by a 1 volt per octave/gate control voltage.

The synthesizer is equipped with a distance sensor that generates control voltage depending on the distance to the object in front of the instrument.

The instrument can be used as a USB-MIDI keyboard. The instrument sends MIDI-CC messages from the distance sensor and the following knobs: fine, attack, decay, sustain, and release.
Archean
Introduction
Controls, indicators and Settings
List of scales in order corresponding to the keyboard keys:
Technical information
  1. MIDI-In. Used for connecting a keyboard or sequencer.
  2. Tune. Coarse pitch.
  3. Fine. Fine pitch .
  4. 1V/Oct. Used for connecting a keyboard or sequencer.
  5. Gate in. Used for connecting a keyboard or sequencer.
  6. Button. Generates a new landscape or starts the settings.
  7. Slide switch for selecting oscillator mode. (1 – triangle, 2 – random landscape, 3 – Metamorphism).
  8. Distance sensor. The sensor converts the distance into control voltage and sends MIDI-СС via USB.
  9. ADSR. Envelope.
  10. Touch Sensitive Noise Generator
  11. Element. A tool with variable functionality.
  12. Attenuator. Voltages adjusting.
  13. Low Frequency Oscillator.
  14. Slide switch for selecting LFO mode. (1 - pulse, 2 – sine).
  15. Delay. Delay time control.
  16. FB. Delay feedback.
  17. D/W. Delay wet/dry mix.
  18. Mult. Signal multiplier.
  19. VCA. Voltage controlled amplifier.
  20. Q. Filter resonance.
  21. Filter. Filter cutoff.
  22. Weathering. Overdrive.
  23. Volume control.
  24. Line out. (-1.2/+1.2 V).
  25. Out for Eurorack systems. (-5/+5 V).
  26. Power jack. (+15 V).
  27. USB-port. For receiving and sending MIDI-Messages.
To enter the settings mode, press and hold the button for 5 seconds. Once the settings mode is activated, the LED will start blinking. The first stage of the settings involves selecting the element function. Choose the desired function or skip this stage by pressing the button. The LED will start blinking twice as fast, indicating that the keyboard musical scale selection stage is now active. Select the necessary scale or skip this stage by pressing the button. When the LED stops blinking, you have exited the settings mode.

Functions in order corresponding to the keyboard keys:
  1. Random voltage
  2. Envelope repetition at the output
  3. Linear modulation of the oscillator.
….list will updated with next firmwares.
  1. Chromatic
  2. Minor
  3. Major
  4. Dorian
  5. Mixolydian
  6. Lydian
7. Wholetone
8. Phrygian
9. Locrian
10. Aeolian
11. Byzantine
12. Diminished
13. Minor pentatonic
14. Major pentatonic
15. Enigmatic
16. Prometheus
17. Geez
18. Hindu
19. Octatonic
20. Maqams
21. Harmonic minor
22. Tritone
Dimensions: 22 x 13 x 5cm
Weight: 450g
Power Requirement: +15V DC (2.1mm tip positive connector)