In addition, there is a small 1/8” ( 3. 2 mm) TRS (tip, ring, and sleeve; sometimes called a ‘stereo jack’) jack next
to the MIDI out connector that was intended for future
controller expansion. The planned accessory was a dual
foot controller that would add a sustain pedal and a
volume/foot controller potentiometer pedal. The function
of the volume/foot controller is selected from the ‘D-pad’
gaming control on the front panel. The D-pad is the four-position flat joystick control on the front panel which
offers switch closures for up, down, left, and right
In summary, Table 1 is a list of the front panel MIDI
functions (note some buttons are labeled differently
between the Xbox, Sony PlayStation, and Wii versions).
You may want to label these MIDI functions like I did
as shown in Figure 2. Since I painted the body of mine,
relabeling was needed anyway. If you do plan to paint the
body on yours, remove everything from the case. That will
make painting much easier, and prevent potential issues
with the electronics.
Let’s Add a MIDI
Now comes the fun part: Tapping those features in
the 1/8” pedal jack. I think most will agree that a sustain
pedal on a two octave keyboard is not very useful.
However, when used on a stage as a keytar, a neck-mounted sustain switch is quite useful for theatrics, and a
look at most higher-end keytars reveals this is a fairly
common feature. We could add another switch to the
neck for this purpose, but there is already a nice
momentary switch mounted on the neck in an ideal
position. The function of the current switch is not very
useful, however. When held down, it causes the ribbon
controller — usually controlling modulation — to instead
control pitch bending. It’s quite awkward to do pitch
bending this way, so I came up with another method.
I added a small SPST toggle switch to an unused area
on the front of the body. I then desoldered the wire from
the current neck switch (labeled ‘overdrive’ on the neck
printed circuit board [PCB]) and soldered it to the toggle
switch. I then ran ground to the other terminal of the
switch. The ground is conveniently located next to where
the overdrive wire was on the neck PCB. Details are
shown in Figure 3. When the switch is closed, pitch bend
mode is activated on the ribbon controller. An open
switch defaults the ribbon to modulation mode.
To convert the existing neck switch into a momentary
sustain switch, I ran a wire from the 1/8” TRS pedal jack’s
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■ FIGURE 1. Stock Rock Band 3 keyboard.
■ FIGURE 2. Repainted keyboard with MIDI functions
■ FIGURE 3. Neck PCB. To start the MIDI sustain
switch function and move the pitch bend/modulation
selection switch, desolder and remove the top wire in
the ribbon cable. It's labeled "over_d" on the PCB.
Next, solder a wire on the underside of the "gnd" wire
solder connection next to the "overdrive" hole.
MIDI Command PlayStation Wii Xbox
MIDI Sequencer Start Start + (plus) Start
MIDI Panic (all notes off/reset) All 3 buttons above All 3 buttons above All 3 buttons above
Keyboard octave decrease by one (square) 1 X
MIDI Program increase by one (triangle) 2 Y
Keyboard octave increase by one (circle) B B
MIDI Program decrease by one X A A
January 2016 31
• D-pad up = (Drum
mode) lowest keyboard
octave outputs on MIDI
channel 10 for playing
• D-pad down = pedal
outputs MIDI channel
volume cc 7.
• D-pad right = pedal
outputs foot controller
MIDI cc 4.
• D-pad left = pedal
outputs expression MIDI