An open, modular guitar-design with some nifty features.

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Compared to this whole world of electronic sound devices like eurorack-modules, drummashines and all this innovative stuff from big and small companies, the electric guitar market looks a little bit boring.

I play guitar but I also like those new ways of making music and I believe that a guitar could integrate great into an electronic music setup. It just needs a kind of redesign - what's technically possible shoud be done, as long as it stays to be a guitar.

Here is my proposal for an open, modular guitar-synth-design with some nifty features to make modern music.


I have spent much time in the past to hack guitars, adding robotic elements to them, messing with control interfaces and audio effects. But I allways did this in a non-destructive way, as I didn't wanted to do something to my babys I couldn't redo. One thing I always wanted to have, but never really achieved on this premise was an illuminated fretboard to display all kinds of information, like scales and sequencers. This problem is the main driver of the project and most of my thinking about building this guitar was how to do this.

As I'm not a carpenter but more an allround maker with typical maker tools like a 3d-printer and a cnc-router, the main challenge was to commit to a concept of building this guitar with those tools I have.

Design Goals

Before I start to decribe the build process in the project logs, here are some specs and design goals I have/had in mind when building the ElekroCaster. This list will evolve.

  • Maker friendly construction (3d-printer, CNC-Router, Vslots)
  • Modular construction
  • Parametric OpenScad modelling (changable string count, scale, space between strings,...)
  • Fully controllable RGB-Led-iluminated Fretboard
  • Touch-sensing-frets
  • Long scale (700mm) for low tunings
  • Two micros, one for audio an one for everything else.
  • Per string signal path
    • hexaphonic pickup
    • hex-preamp
    • multichannel codec (6* adc, 8*dac)
    • Teensy 3.6 microcontroller


Here are two videos, showing the led-fretboad in action. The first one shows a sequencer which is programmed by using the touch-sensing frets. It works not perfect yet, but I think i can improve on that. Notice that the strings are muted and do only sound when the string touches a fret and the sequencer hits an activated step. The strings are hit with the blue device next to the pickup which basically consists of 6 solenoids. I call it kickup. More about that on my next project log.  

Here the fretboard displays a b-major-scale. It's a bit hard to see in the video, but there are different colors for different intervalls: The root is red, the third is green, the fifth blue and the seventh pink. The second, fourth and the sixth are darker and white

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  • The MultEBow

    Frank Piesik3 days ago 0 comments

    "The EBow is a battery-powered electronic device for playing the electric guitar. The EBow uses a pickup – inductive string driver – feedback circuit, including a sensor coil, driver coil, and amplifier, to induce forced string vibrations. The EBow is monophonic, and drives one string at a time, producing a sound reminiscent of using a bow on the strings." (Wikipedia)

    The idea of the MultiBow, which I'm currently trying to realize, builds on this concept. It's essentially six EBows firmly installed under the strings. The allready installed hex-pickup serves as sensor coils and the driver coils are integrated with small class-d amplifiers into another pickup looking package. So the six signals from the pickup are going throug The Teensy-audio-board I use. It has 8 output-channels and I do only need one or two for the main output. One idea was to have additional discrete outputs for each string to process them externally. But using them as part of the MultiBow does make more sense to me, as it opens up the possebillity to modify the feedback signal to alter the effect on the strings (see moog guitar).

    Here is a little demo video to proof the concept:

    Read more »

  • The KickUp

    Frank Piesik6 days ago 0 comments

    The KickUp is an actuator which includes 6 solenoids and a mosfet driver. It's used to hit the srtings from beneath - just the opposite of a pickup. Now the ElektroCaster can play semi-automatically (you still have to use the left hand). See the the KickUp in action in the sequencer video on the details page!  

    Read more »

  • Connection and Communication

    Frank Piesik10/08/2018 at 10:15 0 comments

    Since this guitar is intended to be used in an ectronic music environment, it has to communicate with the rest of the gear, at least to get a clock signal on which it can synchronise it's actions.

    Read more »

  • Body-Neck-Construction

    Frank Piesik10/08/2018 at 09:35 0 comments

    I used three different types of components to build the basic shape of the guitar: 3d-printed parts, 20*20 VSlot profiles and plywood.

    My printer (Creality CR10S4) has build volume of 40*40*40cm. Beeing able to print the shape of a guitar body was the main reason I went for this big printer.

    Read more »

  • Audio-Hardware

    Frank Piesik10/08/2018 at 09:31 0 comments

    Here are some design goals for the audio part:

    • Discrecete audio path for each string to allow for independent audio manipulation.
    • Audio processing happens within the guitar, not on an external computer.
    • Latency under 5 milliseconds.
    • low power consumption to allow for battery operation.
    Read more »

  • Touch-Sensitive Frets

    Frank Piesik10/08/2018 at 08:26 0 comments

    An iluminated fretboad is nice to have, but making the corresponding frets touch-sensitive, the fretboard becomes a powerful userinterface.

    Read more »

  • The Led-Fretboard

    Frank Piesik10/07/2018 at 19:33 0 comments

    Thankfully, we live in the age of smart leds, because the WS2812B make the task of putting over a hundred led into a thin fretboard much easier. I cut an led stripe into its pieces and usesd the template on the left to arrange them and soldering them back together.

    Read more »

View all 7 project logs

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Mark Carew wrote 5 days ago point

Just want to chime in to say Frank this is an awesome build brother! Thank you for sharing hope your able to bring this to the masses for teaching.

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z26 wrote 6 days ago point

Neat, I'm working on something very similar but I want to do an harp instead. (I'm not as advanced in the project as you are).  Single coil pickups can be found as low as 3$ online, so I was thinking of using one for each individual string.  So far my arduino uno can directly listen to the pickup, without any extra components.  The audio isn't good quality, but it's clear enough that I'll be able to play a guitar hero clone with the harp.

I'm still debating what I will replace the uno with.  Since I'll have at least 12 pickups, I assume I'll need two boards (2x the cost).  I don't need as much processing power than you (I want to plug in a pc, not an amp) but I do wonder what kind of quality I could get with a teensy alone (no board).

Alternatively, I could try multiplexing 2 pickups per pin which would half the sample rate of each one.  While the loss of quality of doing so is quite drastic for percussive instruments, it seems much less pronounced for guitar strings.

Good luck with your project

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Brandon wrote 10/08/2018 at 18:58 point

Just wanted to chime in that this is sooo cool!

One thing that came to mind (from someone who has intermittently tried to learn the guitar) is to leverage this type of system for straight-up teaching of the guitar.

Also, I want to productize this something real-bad.  Do you have any interest in doing that?


Again, so sweet!

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Frank Piesik wrote 10/09/2018 at 08:08 point


Yes, the educational aspects of this project are very important to me too. I already have some ideas on how I want to use this for teaching...

I think this could be tailored for just this purpose and be quite inexpensive to produce. So yes, I'm basically interested to make a product out of this, but there are no concrete plans yet.

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Brandon wrote 7 days ago point

Sounds good.  Well for what it's worth I'd be happy to help out.  I think this concept/product could sell well.

How I could potentially help:
1.  I recently met w/ an investment broker over an idea I'm currently prototyping.  He gave me the skinny on what all is needed in a pitch deck, and what will/won't fly.  Based on what you have I think it's enough to throw a pitch deck together and get funded to make this into a product.  (That, or Kickstarter.)

2.  I'm an EE.  So I can help productize that side.

3.  I happen to have a buddy who last year started a Industrial Design and Mechanical Engineering services company, so his business could definitely take the mechanical side through product.

Anyways, here if interested.  In the meantime I'm going to continue to do a slow/cumbersome job of writing Swift code (to make the proof of concept of my idea), until I can convince someone to do it for me.  ;-)


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