Freedom Enterprise Inter Continental Capacitive Ballistic Synth User manual

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Thank you for purchasing the new Inter Continental
Capacitive Ballistic Synth, IC2BS, from Freedom
Enterprise. This small portable synth was designed to
be a new tool in your inventory of sound equipment to
help you get started in the world of sound synthesis. By
reading this manual you’ll become familiar with the IC2BS,
how to use it and how to make the most of it. Good luck,
and have a great experience with your brand-new synth
from Freedom Enterprise.

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CONTENTS
Assembly 4
A Warning About Electrostatic Discharges 4
Bom 5
User Interface 7
Main Pcb 7
Side Panels 8
Interface 9
Booting Up 10
Modes Of Operation 11
Monophony And Polyphony 11
Cv And Gate 12
Features And Controls 13
DCO (Digitally Controlled Oscillator) 13
DCF (Digitally Controlled Filter) 13
DCA (Digitally Controlled Amplifier) 14
Modulation 14
Envelope Generator 14
Specifications 17
Creative Commons License 18
Warranty 19

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ASSEMBLY
Putting together the IC2BS is a simple task if you’re familiar with soldering
electronic kits. You’ll need a #2.5 hex wrench, soldering iron, tin solder, flux and
wire clipper.
These instructions will guide you through the whole process.
Electrostatic discharges, or ESD, can occur when two electrically charged objects,
such as the human body and an electronic device, come in contact with each other. This
phenomenon can be of the order of several thousand volts and can destroy integrated
circuits, like the LM386, PT2399 and ATMEGA328P. To prevent this from happening, touch
a metal surface, like a door knob, before handling any IC.
A WARNING ABOUT ELECTROSTATIC DISCHARGES

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BOM
Comment Description Designator
18650 Battery Holder
Battery Charger BC1
0.1uF Ceramic Capacitor C1, C2, C6, C8, C9, C11,C23
220uF USW0J221MDD1TP C3, C5
0.047uF Film Capacitors .047uF 63V 10% C4
10uF USW1C100MDD C7, C20, C21, C22
47uF USW0J470MDD1TE C10, C17
3300pf Film Capacitors 3300 pF 100 VDC 5% C12
0.1uF Film Capacitors 0.1uF 63V 5% C13, C14
680pF Film Capacitors 680pF 100V 2.5% C15, C16
10uF Electrolytic Capacitor 6.3X7mm C18
0.01uF Film Capacitors 0.01uF 250 Volts 20% C19
Header 1X8 M 2.54mm CN5, CN6
PJ-327U-SMT 3.5mm SMD Headphone Gold Plated CN?, CN1, CN3, CN4
Led Red 5mm D1
DC-DC Booster DC1
Ferrite Bead FB1
LM386 IC1
PT2399 IC2
ATMEGA328 IC3
10 Ω Resistor 1/4 R1
5K Ω Resistor 1/4 R2, R3

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Comment Description Designator
10K Ω Resistor 1/4 R4, R5, R8, R9, R16
15K Ω Resistor 1/4 R6, R10
5.6K Ω Resistor 1/4 R7
1K Ω Resistor 1/4 R11, R14, R15
470 Ω Resistor 1/4 R12
3.9K Ω Resistor 1/4 R13
SPST Switch_Vertical SW1, SW2
Header 1X8 M 2.54mm CN1, CN2
100K Ω Attack, Release, Modulation, Filter,
Pitch, Double, Repeat, Speed RV1, RV2, RV3, RV4, RV5, RV6, RV8, RV9
10K Ω Volume RV7
SPDT Switch SW1
Table 1

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USER INTERFACE
MAIN PCB
Start by snaping in the nine potentiometers in place. Follow the BOM to ensure the
correct values.
Follow this by placing the power switch and solder all the components.
The eight pin male headers will be assembled later.
Start by soldering the Li-Ion Charger and DC Booster modules first. To do this, apply
flux to the pads on the Main PCB and place the modules in their correct orientation on
the Main PCB. Secure them if needed and apply heat with your soldering iron on the pads
of the modules. Apply solder to the pads of the modules and let the solder flow into
the pads on the Main PCB, securing them together.
Do the same procedure to solder the 3.5mm jacks as well as the 18650-cell socket on
the underside of the Main PCB. Ensure the correct polarity on the socket.
Follow this by placing the remaining components on the Main PCB. Start with the
smaller ones such as resistors and ceramic capacitors.

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Notice that the electrolytic capacitors and the LED have polarities and must be
installed in the correct orientation according to the silkscreen on the Main PCB.
Solder these components and trim the leads.
Insert the IC sockets in their correct orientation.
Solder the sockets and only then install the provided ICs.
Insert the eight pin female header on the Main PCB and the eight pin male headers on
the User Interface. Secure the two PCBs with the provided brass standoff and screws and
solder the headers.
Finish off by cleaning the flux left behind and perform a visual inspection.
The side wood panels can be installed by sliding them into the two tabs on the Main
PCB, with the mounting holes facing upward. Insert the aluminium standoff and then the
brass hex screws. Secure them tightly.
SIDE PANELS

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INTERFACE
Figure 1. User Interface.

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BOOTING UP
Insert a Li-Ion 18650 cell in the battery holder with the correct polarity.
Connect a micro-USB cable and a red led should light up on the Li-ion charger
indicating the battery is charging.
Flip the power switch and the LED in the middle of the Main PCB should light up, as
well as a red LED on the DC Booster.
Figure 2. Preset example.

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MODES OF OPERATION
This synth contains two different modes that can be switched by the user during boot up.
In Monophony mode, only one note can be played at the time, however the two built in
DCOs are used to create a ring modulator. This is the default boot up mode.
In Polyphony mode, two notes can be played at the same time. There’s a DCO, DCF and
DCA for each voice. However, in this mode the ring modulator is not present.
To access this mode, press and hold SW1 during power up.
Monophony and Polyphony
Figure 3. Monophony block diagram.

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The keyboard generates a CV and Gate signals that can be used to control other
equipment. The CV follows the 1V/Octave standard. This is the default boot up mode.
To use the CV and Gate as inputs, thereby allowing other equipment to control the
IC2BS, press and hold the SW2 switch during power up.
Both input and output modes, the CV and Gate can only control one note at a time.
CV and Gate
Figure 4. Polyphony block diagram.

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FEATURES AND CONTROLS
DCO (DIGITALLY CONTROLLED OSCILLATOR)
DCF (DIGITALLY CONTROLLED FILTER)
The oscillator is the primary component that generates the sound. Its frequency is
controlled through the keyboard, while the pitch knob controls the octave. The wave
selector knob switches between various waves being generated such as Sine, Triangle,
Sawtooth and Square.
This digital filter simulates the filters found in conventional analog synths. Turn
it CCW for a mellow sound and CW for a brighter sound filled with harmonics.
The filter is internally connected to the Envelope Generator, ramping up and down
when a key is pressed and depressed.

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DCA (DIGITALLY CONTROLLED AMPLIFIER)
MODULATION
ENVELOPE GENERATOR
The output amplitude of the audio signal is controlled through the DCA, following the
envelope generator.
When in Monophony mode, the two internal DCO are used to create a ring modulator. The
speed rate of the Ring modulator is controlled through the Modulation knob.
The envelope generator creates an envelope to control the previous circuits. This
envelope is controlled with two parameters, the attack and release.

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Attack: When a key is pressed, the attack knob dictates the speed at which the
envelope rises from 0 to 100. At full CCW, the rise time is instantaneous. At full CW,
the envelope rises slowly from 0 to 100.
Figure 5. Attack and Release at full CCW.

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Release: The time it takes for the envelope to go from 100 to 0 when a key is
released is controlled with the release knob. At full CCW, the envelope will decay to 0
instantly when a key is released. At near full CW, the envelope will slowly decay once
the key is released. At full CW, the envelope will maintain its position, sustaining
the last note played.
Figure 6. Attack at full CW, Release near full CW. Figure 7. Attack and Release at full CW.

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SPECIFICATIONS
Dimensions in Milimeters
(W/O Side Panels)
Width 120
Height 35
Length 190
Sound
PWM 35KHz
Power
3.7 V @ 25 mA
1860 Li-Ion Cell
Micro USB charge port
Connectivity
0-5V, 1V/Octave CV
0-5V Gate

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CREATIVE COMMONS LICENSE
The circuit design and schematics present on the PCBs are licensed under a Creative
Commons Attribution 4.0 International License. You may share and adapt this work for
any purpose, even commercially, but only when appropriate credit is provided and if the
material is shared under the same license as the original. The PCBs layout, artwork and
names are the property of Freedom Enterprise and may not be cloned or replicated for
commercial purposes. Read the full license at creativecommons.org/ licenses/by-sa/4.0.

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WARRANTY
Fully assembled versions of this product are covered by warranty for one year
following the date of purchase. This warranty covers any defect in the manufacturing of
this product, such as assembly errors or faulty components. This warranty does not cover
any damage or malfunction caused by incorrect use, such as, but not limited to, power
cables connected backwards, excessive voltage levels, or exposure to extreme temperature
or moisture levels. The cost of returning a product for repair or replacement is paid
for by the customer. DIY kits and bare printed circuit boards are not covered under any
warranty and come with no guarantee of assembly troubleshooting or customer support
(although I’ll try help you out).

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IC2BS
OWNER’S MANUAL
Revision A December 2020
Written by Pedro Silva
Art by Seni