(The MIDIpal has been discontinued in october 2014)


The MIDIpal is a smart and small MIDI processor. Insert it between a MIDI keyboard (or sequencer) and a MIDI sound module to unleash powerful compositional tools and effects.

The most versatile MIDI event processor

Compositional tools

  • Arpeggiator: Arpeggiate your chords. 4 modes (up, down, up&down, random), 15 rhythmic patterns, adjustable tempo, rhythmical division, gate and groove, syncable to MIDI clock.
  • Step sequencer: Record step-by-step a sequence of up to 128 notes (with ties, rests, slides and accents), and play it back with transposition. As simple and elegant as the classic SH-101 sequencer!
  • Randomizer: Randomize note values, velocity, and send random CC at each key press.
  • Keyboard-controlled drums sequencer. Control a drum module from a keyboard by triggering and combining patterns — one for each key of a 49 keys keyboard. Create mesmerizing Euclidean drum patterns.
  • Chord memory: Enjoy the classic *chord memory* feature of early 80s synths.
  • Delay. Up to 32 echo notes added after each note, transposition and velocity adjustment for creating feedback arpeggio effects, syncable to MIDI clock.
  • Scale processor. Never miss a note in a solo… The scale mapper replaces each note you play by its nearest neighbour in one of the 25 preset scales. It can also transpose and add voicing/random harmonies.

MIDI message generation

  • Clock: Make your MIDI setup groove! MIDI clock source with adjustable tempo and adjustable groove/shuffle/humanization patterns, from super-tight to funky.
  • CC-LFO: Generate up to 4 tempo-synced LFOs and cyclic automation movements for any MIDI Control Change (CC) message.
  • CC knob: Use the MIDIpal as a knob to send any CC or NRPN message.
  • Controller: Up to 8 sensors / potentiometers (or any voltage source) can be connected to the MIDIpal board, turning it into a versatile “brain” for sensing applications.

MIDI setup plumbing

  • Dispatcher: Play a rack of monophonic synths like a polysynth. The MIDIpal will automatically route each note of a chord to a different MIDI channel.
  • Monitor: Sometimes things go wrong with a MIDI setup… Use the MIDIpal as a trusted source to display the stream of MIDI messages coming from a cable.
  • BPM counter: Use the MIDIpal to check the accuracy of a MIDI clock signal coming from a sequencer or drum machine.
  • Splitter: Control several synths from a single keyboard by routing one half of the keyboard to a MIDI channel, the other half to another.
  • Channel filter: Remove all MIDI messages coming from a specific channel.
  • Channel Merger: Merge several MIDI channels into a single MIDI stream.
  • Clock divider generates a slower subdivision of a MIDI clock.

The MIDIpal can also store 4 custom MIDI transform setups, each of them made of up to 4 filtering/remapping rules.

Other features

  • Powered by a 9V battery or a DC adapter.
  • The MIDIpal source code is open source and easily modifiable… So why not use it to implement your own MIDI transformation features?
  • The MIDIpal is open hardware. Use it as a foundation for your next project requiring MIDI event filtering or MIDI control; or embed one in your DIY instrument to extend its capacities.

Olivier Gillet, Mutable instruments SARL 2011-2017. Except where otherwise noted, content on this site is licensed under a cc-by-sa 3.0 license.