MIDI Keyboard Controller, Part 1

Some time ago I acquired an old Korg DW-6000 synthesizer from a friend's dad.  This thing was at least a couple decades old, and showed it.  But it was a true synth with programmable sounds, and I was interested in playing around with it.

As someone who plays music regularly with various groups, it was not really worth lugging around.  It was big, rather heavy (35 lbs), and didn't have very good piano sounds.  Newer keyboards that people had were full of high quality orchestral sounds, lighter, and also had velocity sensitive keys (hitting the keys harder makes a louder note).  However, it's synthy sounds were nice, as well as could be customized.  So what to do?  Well I decided to rip the guts out and make a rack mounted synth from it.  Then I could install it with the mixer and PA, and people (including myself) could bring their nicer keyboards, and when wanting to use the DW-6000 sounds, plug into it via MIDI.  That however is another project.  For this one, I'm going to use the existing keys and make my own MIDI controller.

Most of the devices you would consider to be a keyboard or synth are actually a combo of two elements: a controller and a synthesizer.  The controller is generally the thing that allows user input (though arpeggiators, drum machines, and playback devices also count).  Most often it is in the form of a piano keyboard and includes the foot pedals and expression wheel.  But there are other forms they can take, from digital drum kits to electronic clarinets and keytars, or even my Virtual Whammy Bar.  These devices all capture the performance and create MIDI commands to send to other devices.  The synth is what you'd expect: it makes the sound.  A controller will tell it to turn notes and and off, or how much vibrato, or a variety of other pieces of info that can affect how the music will be produced.  Again, the controller and synth are often combined into a single package, but can still be used independently most of the time.  A keyboard with MIDI OUT can control another synth, and if it has MIDI IN, there is a good chance another controller manipulate it.

So really, I'm dividing the Korg into its separate functions.  Except, I can capture the performance in more ways than the original DW-6000 could.  I can add a few modern features and a couple more inputs:

• The ability to divide the keyboard up into zones (3 or 4 max).  This means you could control more than one instrument from the same controller.  The lower octave or two could be used to control a bass and the rest of the keyboard could control strings for example.  Of course you need a receiving synth capable of performing different patches simultaneously, which is not uncommon.  A PC would do.  Or most modern synths.
• The ability to set octaves for each zone independently.  If you were doing trumpet and clarinet at the same time, you wouldn't want to only be able to play low notes on the trumpet simply because it's using the lower part of the keyboard, nor only high notes on the clarinet because it lies on the upper portion.  The instruments tonally overlap, and by adjusting their octaves this can be achieved.
• Transposition.  Ever learned a song in an easy key like G, but then been asked to play down half a step because the singer can't hit the high notes (I'm usually that singer, and it's usually more than half a step)?  A transposing feature allows you to adjust the note you're playing by any number of semitones so that you can keep playing it the way you learned.  It is very similar to a guitar capo.
• Patches for different keyboard layouts.  You might have a variety of zone arrangements, each with octave, channel, or even volume settings which you would want to recall whenever you play a specific song.  A store and recall function would prevent having to redo setup work every time.
• Additional input.  The keyboard current has a sustain pedal input, and a joystick which does pitch bend, modulation, and VCF.  I'm adding input connectors for an additional on/off function as well as one more analog input.
• Assignable functions to all pedal and analog inputs.  Depending on the synth, there are a ton of parameters that can be varied in real-time to affect the sound.  This can help achieve more techno sounds, or control more traditional things such as sustain, damper, volume, or whether a chorus effect is on or off.
• A character LCD and some buttons for a UI.  Users will need to be able to do tasks like load up patches, set the keyboard octave, transposition, or channel on the fly.  Maybe not everything can be done at the keyboard, but at least all the things you may need to do while jamming with others.
• A PC program for advanced configuration.  Configuring zones and inputs is going to be a much easier process on a computer than thru the limited inputs on the keyboard itself.  MIDI can be used for dumping and editing patches.

That's more or less the things I want to do.  I have pretty much a set of plastic keys and a joystick to start with.  We'll start blocking it out next time.

Bare piano key assembly