- this circuit is distributed by UNDERSCORES - an open video hardware label : it is available to purchase - as a pcb, kit or assembled unit - at underscores.shop
- the schematic for the circuit can be found here
- the pcb gerber files for the lastest version can be found here
- interactive BOM is here
- consider donating to the underscores project to help us continue creating for the commons
this circuit takes any composite video signal as input and destroys the signal in many interesting and unpredictable ways - due to the nature of analog video glitches for best results you should output this signal directly to a crt tv.
background
this project is an adaption of a video glitch processing circuit created orginally by Karl Klomp known as the rupter. this and many other interesting historic video hardware glitch machines can be seen on web-archive of their site. pictures, schematic and videos of the original circuit are below:
my adaption of it started as an exercise in my intro to kicad workshop for VIDICON_2020 - i ended up getting the boards fab'd and found it to be a very useful device in my studio - worthy of sharing futher!
this project is fully open-source hardware - all the files required to build it are included in this repo for free. if you have the time and/or skill you can contribute back by collaborating on / testing new designs, improving these docs, making demo videos/other creative content etc. you can also support the project financially by donating directing, or purchasing through the web shop.
depending on whether you are going fully diy or buying an assembled and tested unit, some of the following guides will be relavent to you. the flow would be:
parts sourcing guide (w/ notes on pcb fabracation ) - start here if you are building fully from scatch or have purchased a pcb
i try to source all the parts i can from either:
- tayda ; cheaper for common parts like resistors etc, also good for mechanical parts like switches and buttons
- mouser ; has lots more options, speciality video ic's, can sometimes cost more (free shipping on orders over 50euros)
- other ; ocationally there will be parts which will need to be sourced elsewhere - usaully either aliexpress, ebay or amazon etc...
take a look at the full_bom for this project to see where i am sourcing each part from
if you know you will only power rupture with a 5v supply then the regulator part of the circuit (c7, c8, r1, r2, u1, sw9) can be omitted - just connect the middle and left pins on the sw9 footprint with a resistor leg to permanently select 5v power by-pass.
also the values of capicitors on the glitch switches (c1-6) can be customised - i find smaller values are more interesting than larger ones.
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go to the tayda quick order and in bottom corner choose add from file
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select the file tayda_bom.csv in the BOM folder (you will have to download it first or clone this repo)
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after importing select add to cart
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NOTE: the minimum value for resistors is 10, so you may need to modify these values to add to cart (or if they are already modified here you will need to see the full_bom for actual part QTY)
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OPTIONAL: it is a good idea to add some dip-ic sockets and 2.54pin headers/sockets to your tayda order if you dont have them around already
- go to mouser bom tool and click upload spreadsheet
- select the file mouser_bom.csv in this folder (you will have to download it first or clone this repo), then upload my spreadsheet and next
- ensure that Mouser Part Number is selected in the dropdown above the first row, then next, process
- if everything looks correct can now put add to basket
you can support this project by buying individual pcbs from the shop. if you would rather have pcbs fabricated from gerbers directly the file you need is here
- i get my pcbs fabricated from jlcpcb - 5 is the minumum order per design
- upload the zip file with the
add gerber filebutton - the default settings are mostly fine - set the PCB Qty and PCB Color settings (you can check that the file looks correct with pcb veiwer)
- it may be best to combine orders with other pcbs you want to have fab'd since the shipping can cost more than the items - also orginising group buys is a good way to distribute the extra pcbs /costs
i often use jlcpcb because they are reliable, cheap and give you an option of colours. remember though that the cheapest Chinese fab houses are not always the most ethical or environmently friendly - if you can afford it consider supporting local companies.
assembly guide - start here if you have purchased a diy kit
follow this link to view the interactive BOM
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remember to heat pad first (2-3seconds), then add solder, then continue to heat (1-2seconds)
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Checkout the web-comic soldering is easy for more soldering advice
- in general while assembling i start placing resistors and capacitors first. placing 5 - 10 components at a time and then flipping the board to solder them and trim the legs etc.
- next i would do diodes, transistors and ic's - taking care that these are placed in the right direction (using a ic socket can be useful)
- finally i place the interface parts - rca jacks, power jack, pots and switches - make sure these have lots of solder on for structural stablity
- start with the ic if you going for smd part - remember to orient it correctly (follow arrow on silkscreen) - can check connection with multimeter by using the dip pads
- next place resistors and capicators - can also do regulator...
- now place the switches - make sure enough solder is on the outer pins for structural stability
- barrel and rca jacks next
- and finally the pots
operating guide - start here if you have purchased an assembled unit
start by connecting a composite video source to the IN rca jack and a composite video display to the OUT rca jack (use a crt tv for best results) - now without the power plugged in you should be able to see your clean video source on the display by changing the ROUTER switches to both UP or both DOWN
the video input and video output signals can be connected to the effect circuit in 4 different ways - this is because the left router switch will connect the IN signal to the TOP/BOTTOM of the effect circuit, and the right router switch will connect the OUT signal to the TOP/BOTTOM - without power TOP-TOP and BOTTOM-BOTTOM acts as straight signal pass-through. with power these will give different effects.
the REGULATOR switch next to the power jack selects whether the power line is passed through a ~7v voltage regulator -> if you are powering your circuit with 9-12v then you must have this switched on (RIGHT) to avoid damaging your ic. if you are powering with 5v then it can be bypassed by switching to the left, although it wont hurt to still have it on - just changes the effects slightly in some places.
the 4 knobs and 6 switches will control the glitch effects when the power is connected. the default position is all knobs rotated anti-clockwise and all glitch switches set to UP. in general i would start by moving the left most knob first and working towards the right most - same with the glitch switches.
ROUTER positions UP-UP, DOWN-DOWN and DOWN-UP all produce quite interesting and different glitches on a crt screen. UP-DOWN for the most part does little more than a few abstract lines.
how the circuit works
[coming soon]
contributing guide
if you would like to contribute back to these projects in some way but dont know how the best thing (for now) would be to reach out to me directly ( tim@cyberboy666.com or @cyberboy666 on scanlines forum) - i will be happy to help
This circuit is distributed through UNDERSCORES – open video hardware label – visit underscores.shop for more info
The pcb was designed using KICAD
Everything from gerbers, cad files, panels and documentation is freely available online and distributed under CC-BY-SA / open-source licenses – help us contribute to the commons !
Ask any questions or start discussions related to this project on the scanlines.xyz forum – an online community space dedicated to diy av / electronic media art
You can contact me directly at tim (at) cyberboy666 (dot) com Please get in touch if you are interested in hosting a workshop !
thanks to Karl Klomp for inpiring me and so many others, to Bastien Lavaud for circuit advice, always. To Ben Caldwell for project advice. To everyone who has or will contribute ♥♥♥