LZX Industries Cadet Series User manual

CADET I SYNC GENERATOR
OWNER’S MANUAL

ABOUT THE CADET SERIES
i
CADET I SYNC GENERATORLZX INDUSTRIES
The practice of analog video synthesis has an inspiring legacy of innovators, sharers, and doers. In the early 70's, Dan Sandin released
the hardware documentation of his Sandin Image Processor, a video instrument modeled after the Moog synthesizer. It contained
several modules, an expandable architecture, and was an early example of what we now know as the open source movement.
In the mid 00's in Denton, Texas, I was diving deep into the tradition of synth DIY electronics when I stumbled across the documentation
for the Sandin Image Processor and became enchanted. Teaming up with Ed Leckie in Sydney, Australia, we labored to adapt the
circuits in ways that could be built with modern components. These efforts evolved into our own unique take on video synthesis, the LZX
Industries format, and we began selling modules for the EuroRack synthesizer market in 2010.
With the Cadet series, we aim to take our work and give it back to the synth DIY and video hardware communities in a format we wished
would have existed in the early days of our work. Each Cadet module performs a single function and is designed using through-hole
parts where possible. Circuit schematics are published under the Creative Commons Attribution 4.0 International License. If our other
product lines are recipes, Cadets are the ingredients. We encourage you to think outside the box, and to combine these circuits in new
ways. Take the schematics, design your own modules and devices, and release them back into the world.
We salute you, Cadet! Go! Build!
Lars Larsen
September, 2016

ii
CADET I SYNC GENERATORLZX INDUSTRIES
LZX Industries
814 SE 14th Ave.
Portland, OR 97214
USA
www.lzxindustries.net
[email protected]
Creative tools for video synthesis
and analog image processing.
CADET I SYNC GENERATOR
OWNER’S MANUAL
Written by Lars Larsen
Illustrations by Jonah Lange & Lars Larsen
Circuit Design by Lars Larsen & Ed Leckie
Firmware by Ed Leckie
Published September, 2016.
LZX-C1-PCB-V1.1
LZX-C1-FPN-V1.0
LZX-C1-BOM-V1.1
LZX-C1-SW-V1.1
LZX-C1-OM-V1.0

FEATURES
TABLE OF CONTENTS
iii
CADET I SYNC GENERATORLZX INDUSTRIES
SPECIFICATIONS
USER CONTROLS & CONNECTIONS
BLOCK DIAGRAM
1
1
2
2
DIY BUILD NOTES
COMPONENT PLacement DIAGRAM
BILL OF MATERIALS
CIRCUIT DESIGN Notes
5
5
6
9
CREATIVE COMMONS LICENSE
MANUFACTURER WARRANTY
10
10
SCHEMATIC DIAGRAMS 7
EXAMPLE PATCHES 4
INSTALLATION 3

Cadet I Sync Generator (C1) generates the master timing signals required for your modular video synthesizer in both NTSC and PAL
formats. C1 includes a 14-pin video sync output header which transmits timing information to other modules, such as Cadet II RGB Encod-
er, or Cadet IV Ramp Generator. It can also synchronize its timing, and consequently that of your entire video synthesizer, to an external
video source.
FEATURES
1
CADET I SYNC GENERATORLZX INDUSTRIES
Horizontal Sync Pulse, Vertical Sync Pulse, and Frame Clock outputs accessible from frontpanel.
NTSC/480i and PAL/576i timing modes.
Synchronization to an external video source through Video/Sync In. Buffered pass-through of external video signal.
14-pin video sync distribution header output on rear, to transmit video sync to other modules in the system.
Buffered distribution of Horizontal Sync Pulse and Vertical Sync Pulse outs to the EuroRack power header CV/Gate bus.
SPECIFICATIONS
EuroRack Synthesizer Module
4HP
2.25 inches (57.15 mm)
30mA
10mA
Format
EuroRack Width
Mounting Depth
+12V Power Consumption
-12V Power Consumption
0.788 inches (20.015 mm) * 5.059 inches (128.5 mm)Frontpanel Dimensions
499 ohms (3.5mm outputs)
75 ohms (RCA outputs)
100K ohms (3.5mm inputs)
75 ohms (RCA inputs)
Series Output Resistance
Input Termination Resistance
0-1V DC (3.5mm outputs)
0-5V DC (14-pin video sync distribution header outputs)
2Vpk-pk (RCA input/output)
Voltage Levels
NTSC/480i & PAL/576iVideo Formats
Video Sync Distribution Header Outputs Composite Sync
Vertical Sync
Horizontal Sync
Odd/Even Field
Composite Blanking

4
5
6
1
2
3
Horizontal Sync Pulse Out. Positive-going pulse, 0-1V DC. Pulses at the beginning of each video
scanline. 15,734Hz for NTSC. 15,625Hz for PAL. Useful for synchronizing oscillators running above
these frequencies.
1
Vertical Sync Pulse Out. Positive-going pulse, 0-1V DC. Pulses at the beginning of each video field.
59.97Hz for NTSC, 50Hz for PAL. Useful for synchronizing oscillators running at frequencies above
these frequencies, but below the horizontal sync pulse frequencies.
2
Frame Clock Out. Positive going pulse, 0-1V DC. Active high at the beginning of each video frame, and
remains high during the odd numbered fields. Useful to drive sequencing at divisions of the video frame
rate, or into clock dividers to create strobe sources.
3
Video Format Select Switch. Selects between NTSC (480i) and PAL (576i) sync timings. The desired
setting must be selected prior to system power up.
4
Video/Sync In. Input an external video signal here to synchronize C1's timing to an external source.
5
Video/Sync Out. A buffered pass through of the Video/Sync Input. If you are synchronizing to an external
camera, you could pass this signal to Cadet III Video Input (C3) to prepare that signal for patching
throughout your system.
6
USER CONTROLS & CONNECTIONS
2
CADET I SYNC GENERATORLZX INDUSTRIES
BLOCK DIAGRAM
Video Sync
Generator
Video/Sync In
Buffer
Video Sync Distribution Header Out
External Sync Horizontal Sync Pulse Out
Vertical Sync Pulse Out
Frame Clock Out
Video Sync Out
NTSC
PAL
Video Format Select

INSTALLATION
3
CADET I SYNC GENERATORLZX INDUSTRIES
Remove the module from its packaging and connect the 16-pin power cable to the keyed power entry header on the rear of the module as
shown. Connect the other end of the power cable to an empty connector on your EuroRack power distribution busboard. Ensure pin 1
(-12V, with the red stripe) is oriented as indicated on your power distribution busboard.
This module requires connection to other video modules through the 14-pin sync distribution header. This is done through the use of the
Video Sync Distribution Cable (VSDC) available from LZX Industries. VSDC is an expandable bus cable allowing attachment to up to 5
different modules. Connect one of the female connectors on the VSDC to the rear of the module as shown. Each module in your system
with a 14-pin sync header in your system must be connected to each other in this manner. Multiple VSDCs may be chained together to
provide an expandable bus if more than five connections are required.
After connecting power and sync cables, mount the module frontpanel flush to your enclosure's EuroRack mounting rails and secure the
module with the mounting screws provided by your enclosure's manufacturer.
Power down your EuroRack case and disconnect it from AC power outlet while installing new modules.
EuroRack rail
mounting screws.
CV
Gate
+5V
+12V
0V
-12V
EuroRack module. EuroRack 16-pin
power cable.
EuroRack power distribution
bus board.
Power input header.
Red stripe on cable lines up
with -12V on bus board.
Video sync distribution cable
connected to multiple modules
with 14-pin sync connectors.
Male end may connect to additional
video sync distribution cables to
create an expandable bus.

EXAMPLE PATCHES
4
CADET I SYNC GENERATORLZX INDUSTRIES
While a sync generator is an essential module for a video synthesizer, it does most of its magic by simply being there and performing its
job behind the scenes. The most commo patch you will make with C1 is to synchronize your system’s timing to an external video source
before patching that signal through to a video input amplifier, such as the Cadet III Video Input module.
Most video pattern sources and oscillators designed by LZX will receive horizontal and vertical sync pulses through distribution behind the
scenes, such as through the Video Sync Distribution output header or CV/Gate connectors on the power bus. However there may be cases
in which you want to attempt synchronizing other sources, like EuroRack audio modules or laboratory test gear.
VIDEO
INPUT
Composite or monochrome video out
from an NTSC/PAL external source,
such as a camera or DVD player.
Video image prepared for processing
throughout the video synthesizer.
After synchronizing C1 to the external source,
the video is passed through to the input of C3.
Vertical sync pulse sent to sync
input on audio VCO module to
produce a stable pattern.
SYNCHRONIZING AND PROCESSING EXTERNAL VIDEO
SENDING VIDEO SYNC TO AUDIO OSCILLATORS

COMPONENT PLACEMENT DIAGRAM
CADET I SYNC GENERATOR
LZX INDUSTRIES
5
DIY BUILD NOTES
Cadet DIY kits are intended for intermediate level builders. If this is your first DIY electronics kit, or the amount of assembly information
provided is inadequate, you may need to seek instructional material outside of the context of this owner’s manual.
We recommend mounting and installing components in the order they appear in the Bill of Materials.
If you can’t find the 10TF230 PCB mounted toggle switch or find it too expensive, any miniature toggle with a 1/4 inch bushing will
work. Just use hookup wire or resistor clippings to the switch to the PCB pads. We recommend you mount the switch to the frontpan-
el before doing this.
If you don’t want to purchase an assembled Video Sync Distribution bus cable from LZX Industries, you can make your own configura-
tion using 2X7 IDC Connectors and 14-pin ribbon cable.
We recommend securely attaching frontpanel mounted components to the frontpanel before soldering them to the PCB, if it can be
managed. Keep the screws for the M1 mounting bracket slightly loose until the assembly is finalized.
The surface mount VC Crystal Oscillator (X1) should come assembled with your PCB from LZX Industries. At the time of this writing,
this is a hard part to source and we have a limited quantity available. If you didn’t get your board with this part preassembled from
us, the last source we used was DigiKey.
We are assuming you purchased a pre-programmed ATMEGA88A microprocessor from us, with the C1 firmware already installed. If
you didn’t, you can easily install the firmware yourself via the 2X3 pin ISP header (J10) using an AVR programmer such as
AVRISP-MKII and the Atmel Studio software available from Atmel. The firmware (ELF file) may be downloaded via our website.

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2 IC, High Speed Op Amp LM6172 U1, U2
3U5087rotalugeRV5,CI1
1 IC, Microprocessor ATMEGA88A U5
1 IC, Video Sync Separator LM1881 U6
1 IC, Hex Inverter 74HC14 U7
1 IC, Dual Monostable 74HC4538 U8
1 IC, Phase-Locked Loop74HC4046 U9
1 IC, Surface Mount Crystal CSX750VCB13.500M-UT X1
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33.5mm Right Angle Jack w/Nut PJ302M J2, J4, J6
2 RCA Right Angle Jack RCJ-044 J3, J5
1 SPDT Mini Toggle Switch10TF230 S1
1 Right Angle Mounting Bracket Keystone 621 M1
2 Pan Head Philips Screw #4-40, ¼ inch M1A/M1B
BILL OF MATERIALS
6
CADET I SYNC GENERATORLZX INDUSTRIES

A
B
A
B

CADET I SYNC GENERATORLZX INDUSTRIES
9
CIRCUIT DESIGN NOTes
The sync generator is the heartbeat of an analog video system. In the time the average human’s heart has beat once, the video system has
displayed an image nearly thirty times. In each video image there are hundreds of scanlines. In each sweep of the cathode ray across the
television display, there are hundreds of discernable shifts in color and brightness. Video is fast! So fast all you see is the streak left behind
as it sprints. Analog video must keep moving, never missing a step, even when the images between your heartbeats appear motionless.
Orchestrating this race of perfect visual rhythm is the function of your sync generator.
When we decided to build a video synthesizer, the sync generator was the first obstacle in our paths. There were no easy solutions, since
most of the ICs in use as standalone video sync generators were long since out of production. We endeavored to find a solution which
would not rely on any obsolete specialty ICs, and decided instead to use the ATMega88, a low-cost 8-bit microcontroller. We clocked the
microcontroller with a 13.5MHz crystal resonator, a common clock speed for video systems, as it divides nicely down into intervals consis-
tent with both NTSC and PAL timings. With my design partner’s skill in Assembly programming and experience with Atmel microcontrol-
lers, we soon had a working video sync generator.
Cadet I Sync Generator is a direct adaptation of our early work, and you can find the ATMega88 as U5 in the schematic diagram. The U7
hex inverter buffers 5V sync outputs to a 14-pin distribution header for transmission to other modules in the video system. U1 and U2.1
buffer attenuated signals from the microcontroller to drive the Horizontal Sync Pulse, Vertical Sync Pulse, and Frame Clock output jacks on
the frontpanel. Video sync is usually an active low signal, which is the inverse of what most synthesizer modules respond to, so the
frontpanel outputs are inversions of broadcast standard HSync and VSync signals.
Understanding synchronization between two video systems requires another metaphor, that of two runners on a track, one of whom must
match stride in perfect timing with the other. Your sync generator is running perfectly in time with itself, when a newcomer appears. The
newcomer might be a video camera, or a DVD player, or even another video synthesizer. The two are running at roughly the same speed,
but not yet in perfect sync with each other’s gait. Your sync generator observes the newcomer, perceptive and determined, making adjust-
ments until its timing locks in perfect phase. Both devices now begin display of a video frame simultaneously, and each scanline also
begins in tandem. This ability to synchronize with the timing of an external video device is known as genlock. It is what allows you to mix
the output of your video synthesizer’s oscillators and patterns with external sources. Genlock is essential for a modular video system, as
a studio of devices with genlock can all run the same race together.
This external synchronization feature was the next obstacle to conquer in our circuit. It was essential if we wanted to process external video
sources in our fledgling video synthesizer. The LM1881 Video Sync Separator (U6) is a specialty IC designed to extract the synchronization
pulses from any NTSC/PAL standard video signal. The external video signal at J3 connects to U6, giving us several video sync outputs
which we send to our ATMega88 as inputs. This allows our sync generator to perform some tasks in time with the external source, such
as reset the field with Vertical Sync and start a new frame in time with the Odd/Even gate. Matching the gait of the horizontal scanline
requires more delicate control through locking the frequency of the 13.5MHz crystal oscillator (X1) with the phase of the external signal’s
Horizontal Sync.
First, we need the external signal’s Horizontal Sync pulse, and LM1881 only offers us Composite Sync (a combination of horizontal and
vertical syncs.) This is the function of the 74HC4538 monostable (multivibrator), U8, which takes the Composite Sync pulse and extracts
only the horizontal information from it. Now that we have the Horizontal Sync pulse from the external signal, and the Horizontal Sync pulse
we are generating internally, we can compare the phase of the two using the phase comparator function of the 74HC4046 phase-locked
loop IC (U9.) Our goal is to control the frequency of the crystal so that the rising edges of both the external signal and the internal one
occur simultaneously. When the external signal’s rising edge occurs after our internal signal’s rising edge, the output of U9 goes high,
causing our crystal’s frequency to increase ever so slightly. When the opposite occurs, the output of U9 goes low, causing our crystal to
slow down. When the phases match, the output floats -- causing no change in frequency. R21, R22 and C19 form a low pass filter so that
these changes do not occur abruptly. Within milliseconds of observing the new runner, your sync generator’s shoes are hitting the track
at the exact same nanosecond.
U2.2 is used to buffer the external video signal so it may be passed on to other destinations. You might send the external video signal to
the input of C3 next, so it may be prepared for image processing through the rest of your system through DC restoration and scaling.
There is much more to learn about video formats, timing, and the function of the various video synchronization pulse outputs. We haven’t
even touched on the color subcarrier -- something an LZX video synthesizer system typically generates only on output. I’ll leave that up to
the many good texts on video engineering. But now you have something most of those texts don’t offer: a simple, practical example of how
to generate NTSC/PAL sync and maintain genlock to an external source with commonly available ICs and at low cost.
We hope C1 will become the heartbeat of your own video device someday.

CADET I SYNC GENERATORLZX INDUSTRIES
10
CREATIVE COMMONS LICENSE
MANUFACTURER’s WARRANTY
The circuit design and schematics for this work are licensed under a Creative Commons Attribution 4.0 International License. You may
include this circuit with or without modification in commercial and non-commercial works. The PCB layout and frontpanel artwork are the
property of LZX Industries and may not be cloned or replicated for commercial purposes. With the Cadet series, it is our intention to offer
a resource to aid education and inspire the ongoing development and creation of tools for the video artist.
Read the full license and more at creativecommons.org.
Fully assembled versions of this product are covered by our manufacturer warranty for one year following the date of manufacture. 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 warranty covers replacement or repair, as decided by the
manufacturer. Please contact customer service via our website at www.lzxindustries.net for instructions on returning the product. 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. However, we are nice and will help you when possible. Please contact us if you have questions about or problems with
your build.