its actually not that hard to do without any mcu
Here is the DEIMOS CIV a guitar i have built myself about 6-8 years ago:
3 Pickups (2x Humbuckers) every combination possible is selectable, cut of switch / out of phase/ single coil selectable for every combination.
its complex wiring but mangable , here is my build:
notice REAL COW HORNS!!
The skulls are knobs for Volume and Tone for the selected pickup combination
it was a pretty tough fit inside the existing caverns of the guitar
my concernes with the arduino-version:
a mcu circuit could give you issues with interference, noise etc. there is also nearly no room for additional circuitry without cut opening the solid body-->may ruin the sound and give vibrating issues to the body itself.
its overkill to run all the wires out to stomp-boxes and then to the amp(but possible) but this will / may create signal drop and even more noise. with active preamp and then messing around with the signal via arduino etc.. would be no different pickup selection but just a homemade effect box.
That's a cool guitar but I think you vastly underestimate the space those wires takes up. As an example here is a circuit board used in modern Gibson guitars for volume and tone control.
It looks to me like there is room enough for at least an ATtiny85, and that's the hole through version. I bet with surface mount you could cram an entire ATMEGA32U4 or AT90USB1286 in there. The MCUs would not be processing the signal, just routing it from place to place probably using transistors or FETs or relays or something. Honestly, switches can be very noisy, which is why players tend not to play with them in the middle of a song. I think a transistor can be at least as quiet as a regular switch. It's possible that my dreams of a PWM controlled kill switch might be too much but believe the rest is possible and valuable.
this might work , but i think the signal will be corrupted by transistors and so on..there are concerns of musicians about using different WIRE than the original because of different resistance altering sound quality.
there are people measuring the EXACT capacitance of replacement capacitators to match the original and then shout out to the world how they have been ripped off by soemone who sold them a 47nF Cap but it doesn´t sound like "the 47nF" before.
I´have peronaly experimented with different parts in my guitars, now I think the best signal is the one with the less influence.
But I hope you prove me wrong and build an awesome axe.
I agree that there is plenty of superstition around guitars and a lack of scientific evidence around what actually makes something sound good. Thanks for the support. I hope Ben can help me.
Hello. I'm bumping this old thread because I'm planning to attempt such a device like this with the help of someone I met over at the VGuitarForums.
I want this primarily for myself as I have a doubleneck guitar with a piezo hexaphonic pickup so there are a LOT of options to control and it would be best to do this via pedalboard than to twiddle knobs and switches. Manual control is fine for recording but not in a live context. So it's not so much being able to get a certain pickup combination but to make the change instantly without having to stop playing. Concidentally, Ernie Ball made a guitar called the Reflex "Game Changer" that had computer-controlled pickup changes. They stopped making that guitar in 2017 and they never offered any sort of standalone kit.
Sounds interesting, you may want to add this to element14.com/suggestionbox
so any of the element14presents guys can pick it up for a build video(probably myself as I built the guitar shown up in the thread.)
It would be nice if it were more of a group effort. My main interest in this is final assembly as I made the AtariVox+ boards so Ben Heck is a name I know well. Would also like to play around with Arduino programming as I code .Net for a living and the flavor of C in Arduino seems fairly easy to work with.
The main attraction if this were to be a video is the guitars Your guitar is pretty cool and mine has horns too, just not actual cow horns.
There's limited space in the cavity of my guitar as well. Since I wanted this to respond via bluetooth, having it inside a shielded compartment isn't likely to work very well. But hey, the more challenges, the better, right?
Electric guitars uses switches to select which pickups are activated at a time. Most designs though do not allow for all possible combinations of pickups. Also there are alternative ways of wiring a guitar, series/parallel wiring changes the tone. Also reversing the phase (polarity) gives you other sounds. Almost no guitar gives the option of selecting all of these options because the wiring becomes too complex. I would like to challenge Ben to create a system by which an Arduino can be used to select any of the different combinations.
Here are the wiring diagrams to give you a idea.
In-Pase./out of phase
Current mods to help add pickup combinations include:
If you put all these ideas together you get something like what Brian May from Queen built. http://www.premierguitar.com/articles/21307-mod-garage-inside-brian-mays-red-special
Still there is more, pickups with two coils, called "humbuckers" can be "coil tapped" to be single coils, making one more set of switches one might want.
I have a Music Man 'Steve Morse' guitar. http://www.music-man.com/instruments/guitars/steve-morse.html
It has 4 pickups, and switching between them is crazy complicated all by itself. Here is the diagram: http://imgur.com/r5As604
Finally another guitar mod is know as a 'kill switch'. It's basically just a momentary button used to cut the signal to the amplifier, but when used by people like buckethead uses https://www.youtube.com/watch?v=NM8DuJKYlqE
A micro-controller would automate a killswitch and have lots of selectable patterns.
Can you help me Ben? Can all of this be built on to one circuit board controlled by a microcontroller? Possibly even with an LCD display that indicates what mode it's in?