Le Strum kit - Unique, strummable MIDI controller


Sold Out

This inexpensive kit lets you build an unique MIDI control surface which functions something like a cross between a Stylophone and an Omnichord.

Connect LE STRUM to your MIDI synthesizer or computer running synth software, hold down a combination of buttons to select a chord, then use the "stylus" to play MIDI notes by touching the contact pads on the top right of the board. As the name suggests, you can "strum" across chords using the stylus, providing an unique and expressive MIDI controller. Click on the video below and be amazed at what this little board can do!

LE STRUM's 36 chord buttons give you immediate access to 84 different chords (maj, min, dom7, maj7, min7, aug, dim for 12 root notes). You can also play sus4, add6 and add9 chord variations (with some limitations). It is great for learning about chord progressions and can be a helpful songwriting tool.

LE STRUM has a special 6 string guitar mode, which knows basic major, minor and seven open chord fingerings for guitar. It can be used to lay down strummed guitar MIDI tracks without a MIDI guitar, and in a more convincing way that you could get from a keyboard. It's more than a toy, yessiree!

LE STRUM is a unique and fun controller which works great with huge pads and delay effects to create swirls of lush chordy goodness by simply pressing a few buttons. Turn on, tune in, strum out. You could even introduce LE STRUM to cousin ARPIE for some chord arpeggiation fun!

LE STRUM has several performance modes which are accessed by holding the MODE button while pressing one of the top row of chord buttons:

  • Mode+C : Basic mode - Stacked triads mapped across all 16 pads
  • Mode+D : Guitar strum mode - 6-string guitar open chords used (maj/min/7)
  • Mode+E : Guitar sustain mode - as above, but chord held after buttons released
  • Mode+F : Organ buttons - As Basic mode but chord triad plays on MIDI channel 2 as soon as button is pressed
  • Mode+G : Organ buttons with additions - as above but with sus4/add6/add9 options
  • Mode+A : Organ buttons with retrig - as above but chord buttons retrigger
  • Mode+B : Load User Patch
  • Mode+Bm : Save User Patch
  • Mode+B7 : MIDI Panic - All notes off
  • Mode+Strum Pad: Set MIDI velocity (16 levels)

User patch can combine settings for: play on make/break, damp on make/break, guitar voicing /stacked triads, additional guitar octave, enable added 4/6/9 notes, enable guitar chord bass notes, keep chord selection after chord button release, common note sustain on chord change, map chromatic/diatonic/pentatonic scale to pads, enable organ buttons on midi channel 2.

Kit information and build instructions

The Le Strum kit is for self-assembly at home.

Difficulty level: 2/5 (1 = Easy, 5 = Hard).

Previous experience with soldering and kit-building is recommended, but not necessary.


  • Integrated ON/OFF switch and power LED
  • 4mm banana plug stylus with keepy-hole in PCB
  • Designed for hackability (e.g. solder wires to the provided holes on the pads to make proper "strings" to pluck)
  • Transmits on MIDI Channel 1 for stylus activity and MIDI Channel 2 for Chord Buttons.
  • Output is to a standard MIDI 5-pin DIN socket.
  • Size 98mm x 75mm x 45mm (incl MIDI socket)
  • Weight approx 120g with battery
  • OPEN SOURCE hardware design
  • OPEN SOURCE firmware for PIC16F1825 microcontroller.
  • Firmware source code (SourceBoost C) and compiled HEX images available on GitHub (A PICKit2 or equivalent programmer is required if you want to load alternative or updated firmware on to the chip)

Kit contents:

  • circuit board
  • all electronics components
  • mounting hardware
  • pre-programed microcontoller
  • strumming probe with high flexibility cable
  • sockets for integreted circuits
  • DIN MIDI socket
  • battery holder

You will need to provide consumable items like solder, PP3 battery and all construction tools.

See the Le Strum Wiki with build instructions, source code and modding hints.

  • Shipping Weight: 0.12kg

© Lushprojects.com