Make a beautiful custom 3 channel midi controller. Use it for Ableton Live DJing (recommended) or any other MIDI compliant program. Total cost: $450!
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Step 1: The Joy of Buying Your Own Parts...
I spent a lot of time researching the perfect parts for our controller. Since a lot of the drive for making this controller came from the cheap knobs and sliders found on most $50 - $500 controllers, we wanted to make sure each knob, slider and button had the perfect amount of resistance, the proper detents, and of course, looked sharp. Another factor in my selection was the fact that we generally perform in a pitch black room. We wanted something that would allow us to go even darker.
Spend some time getting the right components. Don't like the way something feels? Send it back. Don't bother going to radio shack, they have a lousy selection.
Get spare parts! You might not be able to find something later, and then you'll have a frankenstein controller.
- Doepfer: Pocket Electronics DIY Controller Board ($115)
This board had the perfect amount of documentation for me and the right contol amounts
- Action Electronics KB 7-7 ($29.24)
This seemed like the perfect fit. Nice gentle slope, 7x7x2 7/8. Cheap.
9x EQ LED Tipped Kill Switches
- NTT Switches M2112TCW01 ($8.76ea)
Beautiful, rugged, red LED tipped toggles.
1x POWER ROCKER ($2.49)
- PH-30-850 Rocker Sw.
9x POTS (Potentiometers or the Rotating Knobs) ($1.19!!!ea)
- 313-2000-10K Taiwan Alpha 16mm Ca Linear B10K
For a buck, these pots feel better than anything I've seen on any m-audio controller!?
IMPORTANT!!! These have a "center detent", this means it click in place in the center. I later found out that this is not good with how we have it mapped to Ableton, since we use "EQ 3" which has 0.00dB at about 75% turn, so the center detent is essentially useless.
9x KOBS (the silver piece that goes on top of the pot that you actually touch) ($7.66ea)
- 506-KN900A1/4 Alcoswitch Knobs 1/4" Shaft knurled
Ahh, these are beautiful. Big, shiny, metal. Mmmmmm
1x HEADPHONE VOLUME KNOB (one mounted on the side for headphone volume) ($4.62)
- 506-KN500B-1/4 Alcoswitch Knobs .5" DIA BLACK
3x MAIN VOLUME SLIDER PER CHANNEL ($1.83ea)
- 312-9301-10K Taiwan Alpha Slide P 60mm TRVL Linear 10K
Once again, a super cheap component that feels better than anything out there.
3x PUSHBUTTONS ($2.49)
- 275-644 SPST Pushbutton Switch
Be careful, these are plastic, a millisecond extra on the solder and it'll melt inside. If you find a better button, let me know.
1x BATTERY PACK
- 23-342 9.6V Ni-Cd Battery Pack and Charger Combo Pack ($19.99)
- 10" x 7-1/2" x 4" h Commercial-Grade Case Black
- DIY Foam Cutout Kit
- Threadlocker Blue or any Bolt Locking Glue or Paste (Radio Shack)
- Soldering Station (As a self respecting hobbyist you should have one anyway)
- Colored Wire
Step 2: Prototype
To test various configurations and layouts, we made a cardboard prototype of the Keyboarder case, first of just the face and then of the whole controller. We placed the switches and rockers in their place, then the sliders, and tested whether the distances were right.
Though it's not necessary, and probobly not good for the components (since each time you solder a connection, it deteriorates slightly - as specially the LED tipped toggles and the plastic pushbuttons), I actually wired the whole unit and played with it for a bit to make sure. You should be able to get a good enough idea if your design will work without actually soldering the connnections at this point.
Though I don't remember this, our friend Michael White ostensibly improved our design at this point by staggering some of the EQ pots.
Step 3: Carve Your Case...
At this point I would recommend you have a friend named Pheonix, who has a metal shop, and loves to help friends with their projects. If you don't, anyone with a well stocked metal (or wood) shop will suffice.
Using your cardboard prototype as a stencil, CAREFULLY drill the Keyboarder 7-7 to match all the holes & slots. To make the slot for the sliders, I used a circular saw against the wishes of the Pheonix - although it worked out OK, the slots weren't perfect, and, as Pheonix pointed out, I could have easily ruined my project case.
I also drilled two large holes for the MIDI in and out, and a small one for the power supply in the back of the unit.
Pheonix drilled holes on the bottom of the unit, then threaded the holes in the circuitboard so it mounted on the bottom of the case with 2 screws.
Step 4: Solder + Screw
Hopefully, your new case will fit all the components you've purchased. I kept a drill handy in case holes needed a little prodding.
Screw in all the sliders, knobs and click in the buttons, then clean the components and bolt threadings well, and apply threadlocker generously (or as instructed).
Read the Doepfer manuel thoroughly, it's well written, and covers all you need to know about the wiring process!
The board has a +5v line, a GND line and 16 control input lines from 2 ribbon cables. For each control element, you put the +5v in and then as you turn the pot or slider, the output changes from between 0v to 5v (except in the case of a pushbutton where it will go from 0v in off straight to 5v in the on position). The control input line senses the current voltage and converts it into a midi value of 1...127.
Since our design calls for 25 different controls (9 EQ pots, 9 EQ kills, 3 volume sliders, 3 pushbuttons, 1 headphone volume), but the Doepfer we used only allows for 16, we needed to do some creative merging;
Run the circuit for the EQ lines like this: +5v --> EQ Kill --> EQ Pot --> control line input: this way, we combine the EQ kills and pots onto the same control line!
Once all your control elements are in place, cut & strip the lengths of wire between each connection point & solder up!
Step 5: Add the Battery Pack Hack
Before I finished the controller, I added a 9v battery to power the whole thing. After unscrewing the case 2 times to replace it, I went to Radio Shack and found a model airplane battery pack w/ recharger.
Using two sided tape, I affixed the pack to the inside of the controller, connect the power leads through the power rocker switch, and into the Doepfer board. I left the recharging harness hanging out of the back through the power supply hole I had made for the original power input (on the board itself).
We now recharge it for a few hours, and travel for 2 or 3 performances without recharging since the Doepfer uses very little current.
Step 6: Travel Case
After the controller traveled a little, the pots washers would start to loosen. Even though the controller is pretty solid, travel can still do considerable damage to it. We went to the container store and found this hard plastic case, and a DIY foam kit that allowed us to cut out grooves where the delicate LED tipped switches would be.
It has enough room on the side for the USB to MIDI converter and a few cables, now it's down to a laptop and this small case!
Step 7: Mapping in Ableton Live
Using the MIDI learn (Ctrl+M) function, select each item you wish to control and turn the corresponding knob or button.
Put an "EQ Three" on each channel and map the EQ's accordnigly - you need only assign either the EQ knob or Kill, not both, since they are on the same channel.
You can download the attached .als file to see our template to see our configuration. It will not match yours exactly, since we may have attached different control lines to different control elements.
Save & have fun!