LE STRUM - MIDI Strummed Chord Controller Kit
by hotchk155
Voici LE STRUM!
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.
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
Specifications
- Kit contains PCB and all components and hardware required to build LE STRUM
- Soldering is needed to assemble the kit
- A PP3 battery is required (not included)
- 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)
For more information please click here to see LE STRUM's Wiki
Please note that synthesizer hardware or software is required to make sound. LE STRUM is a MIDI controller and does not make any sound by itself!
12 QUESTIONS
Feb. 26, 2014, 11:07 a.m.
Is it possible to modify Le Strum to a accordion type bass keyboard? I mean with fundamental tones like c1-c2-c3-c4 & d1-d2-d3-d4 etc. Then the chords on the rows below. When you press the chord button it plays the chord (without strumming).
Feb. 26, 2014, 12:05 p.m.
Hi - that's an interesting question! Well I am not familiar with the accordion key layout - but the Le Strum firmware can be changed if you have a PIC programmer and are able to write new firmware for the PIC16F1825.
The keypad has 3 rows of 12 buttons. Is that enough for accordion bass?
Cheers
Jason
Feb. 20, 2014, 5:37 a.m.
Hi! Sorry, this may sound really stupid, but does this work with any hardware synth that has MIDI in?
Feb. 23, 2014, 6:06 a.m.
Hello! Not a silly question at all :)
Yes - this should work with any synth or sound module that can accept note ON/OFF information on MIDI channel 1 (and 2 in some modes). The nature of the playing style on LE STRUM (i.e.chord strumming) means that it suits polyphonic patches and devices best.
Cheers
Jason
Dec. 15, 2013, 6:06 a.m.
Could you tell me how long it would take to ship to the US? If I placed an order today would it make it in time for Christmas?
Dec. 15, 2013, 6:34 a.m.
Hi, Thanks for your question. Unfortunately I would not be able to guarantee any delivery date, but the quoted time for Royal Mail Air Mail to USA is 7 business days. I think it would be unlikely to arrive by the 24th :(
I hope that helps
Jason
Oct. 15, 2013, 2:31 p.m.
Sorry, I should have been more specific. The 5-octave range for triads is more than adequate. But I'm finding the range for scales to be a bit limiting. I have experimented with transposing within my synth, but it would be nice to be able to adjust from the LE STRUM itself. Thanks again, your time is highly appreciated.
Oct. 16, 2013, 12:30 p.m.
Ah - I see, you you mean the modes where you can play a scale on the pads,right?... yeah that should be doable but it would need a change in the firmware. Let me see what I can do
Cheers
Jason
Oct. 15, 2013, 1:58 p.m.
Heya, I was just wondering if there would be an easy way to change the range of LE STRUM, ie. octave up or down. Would it be as simple as assigning functions in the code to unused buttons and maybe adding in an extra variable or two? Being able to shift up and down even a single octave would be incredibly useful, I think. Well, thanks for your help and keep being awesome.
Oct. 15, 2013, 2:19 p.m.
Thanks for your question - currently there isn't a setting to transpose the MIDI notes from LE STRUM, but the easiest way is to get the same effect is to transpose by octaves on your synth/sampler. One issue is that the octave range of the 16 pads is so wide (covering over 5 octaves) that there isn't too much scope to shift the whole keyboard, but I guess it would be nice to transpose so you can play in a comfortable part of the keypad or access *really* low notes. Let me think about that one - could be achieved as a new firmware option
Cheers
Jason
Oct. 14, 2013, 12:45 p.m.
Hallo again, what would be the easiest way to make the notes fade away while still holding the chord button! i would like to play the strum much like a real guitar. the problem is notes tend to sustain until the chord button is released! is there away to change that? i have tried playing with sustain mode but i am not sure if using that function would help me with what i want! i am going to build a like to box for this gizmo, that would make really fun to play! thanks again! cheers hasan
Oct. 14, 2013, 12:58 p.m.
Hi Hasan, the strum controller is only sending out MIDI note ON/OFF messages, so to change the dynamics of the sound (attack, decay, sustain, release) you need to experiment with your synth/sampler you are using to make the actual sounds (just like with a controller keyboard). With a decent hard/soft synth you'll have full control over the amp envelope so you can get whatever fade out rate you like. Try experimenting with different sounds or even different sound packages. I use Reason but there are many options, some free
Hope that helps
Jason
Oct. 1, 2013, 12:17 p.m.
HI, How difficult would it be to modify the code to provide an alternative keyboard layout? Is the source code available in a reasonably high level form with comments ?
Oct. 1, 2013, 1:44 p.m.
Hi - the kit is open source, and the code is here:
https://github.com/hotchk155/Voici-Le-Strum/blob/master/src/StrumController.c
It is certainly possible to change the code, you'll just need a PIC programmer (like PICKit2) to flash the MCU with your new code
I'd be interested to hear how you get on
Cheers
Jason
Sept. 28, 2013, 3:59 p.m.
How difficult would it be to implement a MIDI-in jack to pass clock data through to the synth?
Sept. 29, 2013, 3:46 a.m.
If you mean hacking one on to existing LE STRUM - you'd need to add an external jack/optoisolator and connect the data line to to pin 8 of the PIC (currently connected to the MODE switch). You'd need to change the firmware to implement MIDI thru.
Better is probably to use another device to merge the MIDI data from your MIDI clock master and LE STRUM. Maybe you can use a keyboard with a separate MIDI THRU. The only device I currently have that could do this is an Arpie (Unfortunately you generally can't just merge MIDI signals electrically - you need switching/buffering logic)
Hope that helps
Jason
Aug. 11, 2013, 11:49 a.m.
Thanks Jason for the great Le Strum, I eventually found some spare time to put it together and can't leave it alone since then :) I'm sure you'll get some orders from impressed friends as soon as they see it. I'm ordering an Arpie straight away and please let me know when you'll release some new mini controller/instruments. Keep up the excellent work - Dan
Aug. 12, 2013, 12:17 p.m.
Thanks Dan! Cheers for the nice comments. Yeah I do have a few other things in the works, just struggling with time right now :\
July 31, 2013, midnight
Hello, I'm about to get two of these but I'm considering a third just to try a crazy idea of mine. Does it have any latency if you do use a string (read your modding suggestions) instead of the pads? I'm thinking I'd like to be able to pluck the same note repeatedly at a rapid pace and that can only be achieved with a string. But I'm not sure how realistic that would be and I'll like your feedback since you tried it already. You can bet you'll be seeing at least one cool re-boxing of this great device in the near future!
Aug. 2, 2013, midnight
Sounds interesting! There should not be a noticeable MIDI message lag as such (although soft-synths and the like do have latency), however the device does need to "scan" the pads, so there will be a "shortest note length" that can be played on it. However I think this can be very short indeed as the scan rate is very fast (100's of times a second). Be interested to see how you get on
Cheers
Jason
June 28, 2013, midnight
Hi there, I have an order for one of these beauties through! I wanted to case, hold and play it like a guitar, so play chords with the left hand while strumming with the right, but downwards. It looks like the strumming goes upwards, any way to change this, while building or through firmware? If it's firmware only would you consider to implement it? cheers and thank you very much for your creation!
June 28, 2013, midnight
Hi, Thanks for your question. It sounds like you probably would want to add your own set of strings "off PCB" to strum, in which case you can simply arrange the strings in the reverse order if needed. Please check the following wiki page which may answer your question
https://github.com/hotchk155/Voici-Le-Strum/wiki/Hints-for-modding-LE-STRUM
if not please let me know
Cheers/Jason
June 18, 2013, midnight
Hi, I'm very interested on the kit, but I would like to know if the boards come with nothing pre-soldered. I'm thinking on making something bigger, more ergonomic, maybe with arcade buttons. Would that be possible?
June 28, 2013, midnight
Thanks for your question. Yes the board is completely unassembled and it would be possible to fit it inside a case with some larger buttons and bigger playing pads. The electronics should work OK as long as you wire up the switches in the correct configuration. I would also advise keeping wires as short as practical.
I think it would be possible to retro-fit such a setup to a fully assembled LE STRUM by soldering additional wires to the solder joints on the bottom of the switches and LEDs. The pads and stylus already have additional spare solder points.
If you do make such a thing I would love to see it and feature it on a upcoming "hacks and mods" page
Cheers/Jason
EDIT: Please see https://github.com/hotchk155/Voici-Le-Strum/wiki/Hints-for-modding-LE-STRUM
10 REVIEWS
Everything is ready for build, manual is easy to understand
Feb. 25, 2014
Just got my Le Strum today very straightforward build looking forward to having a proper explore of it . But so far looks to be a brilliant piece of kit
Jan. 16, 2014
I'm not experienced at soldering but having done one project I found no problems with this.
The finished kit is sturdy, very small and very cute. As a controller it is like nothing else out there and is a lot of fun to use.
Jan. 8, 2014
This was a very well put-together kit. Everything was included (even a few extras of this and that) and the kit went together relatively quickly. I would say that I'm an intermediate-level assembler of soldered kits and this took me about 1.5 hours to put together. You will need an iron with a fine point, but that's a given with this type of assembly.
Once assembled the controller works flawlessly. I haven't had a chance to use it very much yet - I just connected the DIN-out to a midi to USB interface and ran that to GarageBand on my MB Pro. The number of preset settings packed into the device is really impressive and I've been having a lot of fun with the various guitar modes.
Outstanding! Thanks for taking the time to create and share this.
Dec. 23, 2013
A nice kit that works.
I originally bought this because I wanted to strum my guitar samples - which it does very well.
Instructions are clear and straightforward and it's easy to put together.
Team this up with your favourite sample player or synth and you can add a new creative dimension to your tracks.
Looking forward to modding it a bit and experimenting.
Will definitely be using it in my next album.
marksmusicaustralia.com
Dec. 10, 2013
Excellent idea and great Midi implementation!
It could use some ergonomics tweaking (I know it has been done this way to save on PCB costs) because it is not the best for playing too frantically, but it sounds super!
Using a 6 voice poly synth, some distortion and delay, it sounds killer. The functions and presets are quite useful, and allow for a wide variety of playing.
Kit was well packed and instructions clear and precise. It took about an hour and a half in experienced hands, but anybody with patience and solder can do it!
Nov. 26, 2013
Great instructions, quality components and a unique design add up to a fantastic kit!
Aug. 11, 2013
Easy to build (thanks to the bullet proof instructions) and great fun to play!!! The firmware covers many options and makes it easy to adjust LE STRUM to your own way of strumming. It was such a pleasant surprise to find a "Toggle strum direction" after discussing it with Jason... I can't recommend this kit and its creator enough. Off to strum all night now!
Aug. 11, 2013
The kit is easy to build. There are more components than you need so you can replace a component that you have bad soldered.
Le Strum is very funy to play with the synth of your choice. I use it with a Shruthi and it's great.
July 30, 2013
Works like a charm, unlike any midi controller i've used before. easy to build and good looking boards.
cheers!
July 30, 2013
SHIPPING RATES
Rates to United States
| Shipping Rate | First item | Additional items |
|---|---|---|
| Royal Mail: Over 100g: Air Mail Standard (Not Trackable) | $7.50 | $2.90 |
$50.00
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