SamplerBox should start right up. Next time you
reboot, SamplerBox should automatically come up with
your changes operational. This is all Linux stuff, and if you
don’t need to change anything, you can safely ignore
everything I just wrote.
There are no requirements for packaging this project if
you are only interested in experimenting with
SamplerBox on the RaspPi. An exposed Pi with a
bunch of protruding cables and USB modules does
not a robust instrument make, however.
Because I plan to keep my mellotron around for a
long time and the fact that it will be moved around
and probably even used in a live environment, meant
that I needed to package it up for its own protection.
To this end, I built a 6-3/4” x 4-1/4” x 1-3/4” box
made of 1/4” MDF and, of course, painted it a metal
flake copper brown as shown in Figure 6. Figure 7
shows that the top of the box was made of 1/8”
I suspended some perfboard from the acrylic top
using 1/2” spacers. I mounted the RaspPi 3
underneath it and the LCD display on top.
The MIDI interface circuitry is built on the
perfboard. Three pushbutton switches (Function,
Increment, and Decrement) are mounted
directly to the acrylic top. On the right side of
the box, I have mounted a 1/4” phone jack that
internally is wired to the output of the USB
I have the power connector, reboot
pushbutton switch, USB port connector, and
the MIDI connector on the back of the box.
The output jack, reset switch, and the power
connector are glued to the box, whereas the
USB port connector and the MIDI connector
are mounted to the perfboard and protrude
through holes machined in the back of the box.
I left enough slack in the wiring so that the top
with the suspended circuit board can easily be lifted
out of the box for maintenance. The rat’s nest of
wiring is shown in Figure 8.
Figure 9 and Figure 10 show the operational
Building the SamplerBox mellotron was
challenging and fun, but having a functional
mellotron around is even better. I already know my
next series of recordings will have the ethereal
sounds of the mellotron playing a prominent part.
You may be wondering why I didn’t just buy a
keyboard with a large number of sounds available. To this,
I have two answers. First, I enjoy building the things I use,
and second, I am not aware of any keyboard that has
mellotron sounds built in.
Remember, even though I use my SamplerBox mostly
as a piano and mellotron, you could use one you build for
yourself for drum sounds, brass instruments, human
voices, or who knows what.
Surprise us! NV
32 September 2017
■ FIGURE 6.
Painted box with
■ FIGURE 7. Packaging planning. The LCD display is on the front
of the perfboard, with the Raspberry Pi 3 on the back side.
■ FIGURE 8. A rat’s nest of wires. I used point-to-point wiring.