
flight of harmony
Eurorack and Fractional-rack Modules
~rev1.1~
1/6

Specications
Supply Voltage (min –> max) ±9V –> ±15V
Supply Current (max draw @ ±12V) +12V: 14.1mA –12V: 13.7m.A
Input Voltage (@ ±12V) -V
Max Output Voltage
Input & Ouput (I/O) coupling Direct
Output Impedance 1kΩ
Scaling 0% –> 200% / V
Offset range ±5V
Gate output Off: -V
Trigger Output Off: -V
Trigger duration 1.5ms
2/6
—> +V
supply
±
supply
supply
12V
supply
supply
On: +V
On: +V
supply
supply

Components
1 Assembled Choices module
1 DC power cable – (euro) 9” Ribbon cable w/10-&16-pin 0.1" connectors
(frac)18" 4-wire cable w/ 4-pin 0.156" connectors
Overview
Well, it's a joystick, isn't it? A basic joystick is used to provide an
easily-varied control voltage (CV) to other modules, often allowing the input
of a DC CV that is then either amplied or attenuated by the joystick before
being sent out to other modules.
The Choices joystick is designed to have as much utility as possible
while keeping the price down. Offering only DC control seemed improper,
so the Choices was congured to operate with AC input as well as DC. A
brief rundown of the features:
It can be oriented with joystick at the top or the bottom to best suit •
its location in your system.
Separate Gate and Trigger outputs•
Two trigger buttons for ease of ambidextrous access, regardless of •
orientation.
Toggle switches to select optimal reference level for either AC or •
DC inputs.
Usage Details
Supply: This design has been tested from ±9V up to ±15V and
works well in this range, although performance specics will vary with
supply voltage. All measurements, unless stated otherwise, assume V
= ±12V. All units have a polarized or shrouded power header to ensure
proper connection. Supply polarity symbols are also silkscreened on the
PCB in case of non-standard cables or supply bus.
Orientation: Choices is congured to operate with the joystick at the
top by default. If you wish to rotate the unit, the output will be reversed in
respect to the operation of the joystick - up will decrease, down increase, left
increase, right decrease. To correct this, simply unplug the green connectors
that are connected to the joystick, rotate them 180° and plug them back
in.
Joystick tension/mobility: All joysticks have a clear silicon lubricant
applied to the ball joint during assembly for ease of motion. If the motion
becomes "dry" over time, lube it up baby. Electronic control lubricant is
recommended.
Each joystick assembly is slightly different in its physical
supply
3/6

dimensions, which affects the feel of the unit. Because of this, no xative
has been applied to the three machine screws that hold the assembly to the
panel. The feel can be adjusted by tightening or loosening these screws with
a T6 Torx© or equivalent Star-drive driver. In case a screw should become
lost, they are M2x0.40 7mm button-head machine screws.
Controls, I/O
X: Horizontal axis, left or right motion output
Y: Vertical axis, up or down motion output.
Scale: Controls the scaling/gain of the signal. Middle position is
unity gain/1:1 scaling, counter-clockwise attenuates, clockwise amplies.
Offset: Controls the offset or bias of the signal. Used to shift the
output up or down.
Ref: Reference level for input. Put switch lever in direction of the
wavy line if using an AC input signal, or toward the at line for a DC
signal.
In: Input signal goes here. When a plug is inserted, the unit
automatically switched from internal DC source to the input signal.
Out: It's the output, where the new signal comes out.
T: Trigger output.
G: Gate output.
T/G: Pushbutton to initiate Trigger and Gate signals.
Bias adjust
Figure 1 shows the rear
of the PCB. The trim pots shown
control the default amount of
bias or offset of the output.
During testing, the unit
is adjusted for minimal bias
with an AC input signal. This
will not satisfy all situations of
course, so you may adjust the
bias to suit your needs.
4/6

Stuff
on the Muffwiggler forums, come check it out! People have posted some
excellent demos on there. I haunt the forums as well, and new things are
posted there long before they hit the f(h) website.
A big thank you to those who have sent in suggestions and
comments, keep them coming!
Send samples to: samples@ightofharmony.com
Comments, suggestions, complaints to: ight@ightofharmony.com
Drawings and designs ©2009 ight of harmony / Red Hand Studios
There is a lot of discussion about new and upcoming f(h) modules
http://www.muffwiggler.com/forum/index.php
http://www.ightofharmony.com
edition 1, 4/09
we miss them.
5/6