16 Voice Demon Core Oscillator

The catch of our Demon Core Oscillator is in a new innovation called the MDCO (Multiperiod Digitally Controlled Oscillator) which allows a single analog oscillator core to form multiple simultaneous waves with pitch and phase control. In practice this means 16 analog voices which can be controlled separately.

The sonic gravy is found in the fine tuning of the voices. They can be set in strict digital tuning, be statically detuned (spread) or set to drift (Core Stability). Or both. The spread control takes us from a brutalist digital cityscape to super saw planet while the core stability ranges from vintage DCO synthesizers to a broken and misbehaving vintage VCO. On the middle ground of both controls the sound resembles that of the old warm VCO designs of the 80’s (which we are very fond of).

The basic building blocks are saw and pulse waves (with PWM) but more complex waveforms can be created using two or more unison waves and triggering the phase sync via the sync trigger input. Simultaneous unison waves in the same phase increase the amplitude but when slightly detuned they generate strange harmonics and form unusual waveforms. If more voices are used, spread is opened slightly and the sync trigger input is used with gate signal, the phase sync acts like a decay envelope producing flanging effect. This can be used for massive bass synthesizer sounds.

All of the voices can be configured in different depths of unison and octave stack. Up to 6 octaves are supported. The 16 voices are spread evenly between the octaves.

Since we know the precise tuning of the waves the master tuning can be accurately set in A440 across 6 octaves via a tuning LED. This makes the module handy for practical applications requiring accurate pitch. The 1V/Oct pitch control is calibrated to high precision. A bipolar linear FM with a attenuator controls the master pitch in conjunction with the 1V/oct input.

While the Demon Core Oscillator stores megatons of energy in itself, it can be boosted to maximum yield by attaching the Demon Core Expander to it. Check it out over here.

Tech specs:

  • 12hp, skiff friendly with 25mm depth.
  • 120mA +12V and 20mA -12V
  • 16 configurable voices (octave, stacks)
  • Saw and pulse waves with PWM ranging from 0-100%
  • Coarse tune for 6 octave range with half-step increments
  • Fine tune for ± half step range
  • A blinking tuning indicator for finding C note in every octave and A440 fine tuning
  • 1V/oct master pitch CV
  • Linear FM CV (±5V) with attenuator
  • Combined Spread / PWM CV (±8V) with offset function
  • Stability CV (±8V) with offset function
  • Trigger input for synchronizing the phases for all waves
  • Mono audio output
  • A function (shift) button to do magic for different controls!
  • Software updates via audio
  • Secure shrouded power connector with a supplied power cable

Firmware updates


You can update your Demon Core Oscillator’s firmware by holding WAVE, FUNCTION and VOICES buttons and turning the power on. The module then enters bootloader state. You can connect your computer or phone’s headphone output to FM CV jack and play the firmware audio file. The progress is shown on the voices LED array. After updating the firmware the module enters play mode.

From an ordinary headphone output on a smartphone, volume should be turned way up to achieve proper result. WARNING: the audio files below contain 56k modem-esque DAMN LOUD audio. Don’t damage your ears or audio equipment with it.


DCO Firmware 1.1


  • Virtual VCA zipper noise at medium release and attack times has been significantly reduced.

Bug fixes:

  • At 5 voices, stack depth 3, using the pulse waveform, the maximum frequency was limited to about 600Hz, above which the frequency would wrap down by an octave. This has been raised to 2.5kHz

DCO Firmware 1.0

  • Init release
  • Modules 1-100 have this firmware when shipped

Other useful info