Single string pickup/sensor for MIDI

[CaptainTuna]

Hey guys,

let me start off by saying this is more of an electronics project. I study electronics and telecommunications at university, and whenever I can I try to find some sort of connection between this and bass guitar, somehow.

Anyway, I want my bass to output a MIDI signal, and I'm looking for some sort of sensor or pickup that understands when a string is being plucked; more of a sensor, since I don't need to output the signal to an amp, I just need to know if the string is being plucked, that's all. Oh, and I need one per string.

I have no ideas though, probably because it's almost bed time. Most I can think of is hall effect sensors with magnets on the strings, but I'm sure you guys can give me a better solution.

 

[line6man]

This is often done with piezo saddles.

 

[megafiddle]

There is also the Roland GK pickup, which has 4 tiny humbucking coils, one per string.

The conversion to a midi signal is normally done outside the bass though. The output
of the GK or piezo pickup is just a 4 channel audio signal. I think the only things available
for installing in the bass itself will only provide the audio signal.

Do you just need a signal indicating that a string was plucked? The audio signal can be
processed into a note "trigger" using analog synth type circuits or modules.
But if you also need note information, than you will need a pitch to midi converter.

 

[CaptainTuna]

Do you just need a signal indicating that a string was plucked? The audio signal can be
processed into a note "trigger" using analog synth type circuits or modules.
But if you also need note information, than you will need a pitch to midi converter.

I basically need to identify which string was plucked. NO other information, I don't care what fret or note is being played, just what string is being played.
I guess going for the Roland's divided pickup is overkill, even because it costs 250$ :| .

I've also checked out piezo saddles and it looks like they cost a lot as well, unless I find some sort of seller which sells piezo coax cables but haven't found much last night.

My other idea would be: fit some tilt swtiches, or piezo sensors foam and stick it under the bridge, not a single piece of foam but 4 mini strips of it, one per string.

 

[megafiddle]

You might want to register over at vguitarforums.com:

http://www.vguitarforums.com/smf/index.php

Might be someone there has built their own pickups. Even designs that didn't work well
for them (because of poor audio) might work well for your application. Lots of different
sections there, some for bass, but even the guitar type stuff could be applied.

 

[grisezd]

If you're a pick player you could isolate the strings electrically (plastic nut and wood bridge, maybe) and use a metal pick wired into a circuit. When the metal pick touches the metal string you get a completed circuit? Messy, maybe, but cheap.

 

[CaptainTuna]

You might want to register over at vguitarforums.com:

http://www.vguitarforums.com/smf/index.php

Thanks! I'll see what I can find on that forum as well.

If you're a pick player you could isolate the strings electrically (plastic nut and wood bridge, maybe) and use a metal pick wired into a circuit. When the metal pick touches the metal string you get a completed circuit? Messy, maybe, but cheap.

Not a bad idea. I was going to isolate the strings anyway so this could work. But I'm a 50/50 fingers/pick player so I'll see if I can find something better, but I'll definitely keep in mind this solution. Thanks!