The first module to be added to the wonkystuff MIDI range is a MIDI Controlled Oscillator (MCO), approximating the voice architecture of a single oscillator of the Roland Juno-6. For an overview of the wonkystuff MIDI modules, I have written an overview article.

The module consumes MIDI signals from any of the MIDI channel outputs of the mb/1.

PLEASE NOTE: This module requires the mb/1 module in order to function correctly - it does not directly connect to MIDI devices!

• Inputs:
  • MIDI serial data (I)
• Outputs:
  • Oscillator output (x2)
  • Gate (Stays high whilst a key is pressed)
  • Trigger (5ms pulse whenever a new key is pressed)
  • MIDI Thru (T).

Further details

The module responds to MIDI notes 21 to 91 (A-1 to G5 - although as a digital oscillator, aliasing is evident at the higher reaches!) and uses last-note-priority, remembering up to 8 held notes. When a note is released, the pitch returns to the previously held note — when the last note is released, the output remains at that pitch to allow for slowly decaying notes.

MIDI Specification

Parameters of the audio waveform are controlled using MIDI CC messages and/or program-change messages and is loosely based on the Juno-6 voice architecture. Each parameter has a range of 0-127, allowing for quite a few different waveforms!

• Sub Oscillator:
  • A square wave siting one octave below the main pitch
  • Level controlled by MIDI CC 5
• Ramp:
  • A rising sawtooth wave
  • Level controlled by MIDI CC 6
• Square
  • A square/pulse wave
  • Level controlled by MIDI CC 7
  • Pulse controlled by MIDI CC 8
  • PWM mapped to mod wheel (CC 1)
• Noise
  • Digital sequence of random pulses, based on the noise generation algorithm of the DR-110 drum-voice clones</td>
  • Level controlled by MIDI CC 2

In addition to the above MIDI CCs, mco/1 also responds to some Program Change messages, as follows:

• Program 0: Recall the stored voice parameters or, if none have been written yet, the default ramp waveform
• Program 1: Recall the default patch — ramp waveform at maximum volume, all other waves set to zero
• Program 2: Randomise the voice parameters!
• Program 7: Store the current parameter set into Program Location 0 — this will be recalled upon next power-on, or by recalling Program 0

Unfortunately it is not possible to link product stock levels with those from the regular wonkystuff shop, so there might be times when items are not currently in stock. In these cases I will contact you to update the expected shipping times (which will need to include the manufacturing time of course).

This is not my main job, so shipping has to fit around evenings and weekends — please feel free to contact me if you think things are taking too long!