JP90 bass as midi controller

Interesting project. Design of the controller and writing the software took longer than the final build.

Category:

Music

Tags:

• bass
• midi
• guitar
• lutherie

[Zone1242]

HI, it depends on what you want to do. My project was to get a certain number of midi notes to trigger a midi drum machine. The design replaces the classic midi keyboard switches with ones made when a string touches a fret. So, the strings have to electrically isolated (separate bridge pieces, etc.) and the frets have to be wired up. If you want all of the notes from the bass available then I'm not sure of that's feasible - all frets would have to be wired.

[NepherIsis]

Hey, great idea! How can I construct one of this?

[Zone1242]

@NepherIsis It depends on the complexity of the design. My project was to provide a limited number of midi triggers intended to drive drum sounds to accompany the 'real' bass playing. You'll find various interface circuit designs on the net - I used one from Parallax based on their chipset. As for the physical construction, hopefully the images give some ideas - depends on the instrument you want to mod. Each string must be electrically isolated hence you need separate bridge pole pieces.

[myhapylife]

You have midi out now an you can play keyboards an synths?

[Zone1242]

I'm not sure I understand your question. The goal was to use the instrument as a midi controller linked to a drum machine so the player could set up a drum track alongside the bass, in effect playing both at the same time.

[cecreohm]

Uh, any word on that software? I really want to know, did you buy that board or build it?

[Zone1242]

Did this project back in 2003. The board is by Parallax and uses one of their Stamp micro-controllers. The board has a patch area for building custom interfaces - mine was built around the 74C922 keyboard controller chip. The sw was written using the Stamp editor, etc. I have the source code on the really old PC I used back then so I'll see about getting it off there and post it somewhere. Can't find the final circuit diagram though....

[BN2Ofly]

hey there Zone i do have a question. I m trying to get a midi bass because i want to work with a friend of mine who is dj . We need a midi signal from my bass to work with ableton. i wanted to ask, if you only need the things you putted in your bassl? yesterday i was in a musicshop and they told me that you can only get a midi bass by using a roland kit, and that you need also some box from roland which costs about 800 euro, what is way too much for a student. hope you can help me out.

[cecreohm]

Don't worry about finding the code on account of me. Thanks for the reply!

I have a bunch of tone decoder chips (they output a logic high when they detect a signal within the range of their connected bandpass filter) and I have been thinking about gutting a usb gamepad to create an interface to use a guitar or keyboard as a game controller. With all the stuff I wanna do I'll get to this in probably about ten years though.