CHA/V 3.0 (2021) is the newest DIY PCB version of the cheap, hacky, audiovisual synthesizer, based on the tutorial “How to Make a Crap Video Synth for $10”, and recently included in Handmade Electronic Music. If you are new to video synths, fasten your seatbelt. You just opened up a huge can of wormholes. This page offers PCBs to build a standalone AV synth, the list of other parts needed can be found with the build guide linked below.
VGA devices have a surprisingly tolerant window for accepting signals that are nowhere near spec. CHA/V devices happily hurl garbage into that window. This is not a precision instrument by any means, but it’s a cheap and convenient way to experiment with VGA hacking and video synthesis basics.
Updates from CHA/V 2.0 (2019):
- improved signal routing
- improved component footprints (easier to build)
- expansion header for use with VGA4EVA
In previous versions it was necessary to source a VGA test signal generator and wire it to the CHA/V. This is still an option, but no longer necessary when the CHA/V is built with VGA4EVA.
Who is this for?
- “I want my modular synth to make purdy-pitchers while I play it”
- “I like making DIY audio circuits, like the Atari Punk Console. Is there something like that for video?”
- “I’m interested in DIY video devices or circuit-bending.”
The CHA/V is not:
- the “correct” way to synthesize video
- made from quality parts
- capable of precision
The CHA/V is:
- lots of fun
goodeasy way to get started in video synthesis!
(above video shows PCB v2.0)
VGA4EVA is a hacky DIY VGA signal generator based on Arduino, and designed as the first CHA/V expansion module. Prior to VGA4EVA, it was necessary to source a VGA test signal generator and wire it to the CHA/V
VGA4EVA is named for the useless Ali Express customer service bot that you get to deal with when one of the many unreliable sellers fails to ship your VGA test signal generator. VGA4EVA replaces the test signal generators and adds some features:
- Patchable triple filter/attenuator
- Background patterns and sync are hackable
- RGB background pattern channels are independently patchable
- Background patterns can be used as weird oscillator sync sources
- Dedicated 3.5mm output jacks for horizontal and vertical sync pulses
- No longer requires any wiring — easy CHA/V connect/disconnect via pin headers
VGA4EVA is compatible with CHA/V 3.0, and also CHA/V 2.0. Previously built versions of the CHA/V 2.0 require a free adapter PCB.
Although VGA4EVA was designed to be the brain of a CHA/V, it can also be built as a standalone device with limited functionality. As a standalone device, VGA4EVA can act as a rudimentary video encoder and sync source for audio oscillators.
Please note that for the build-phase only, VGA4EVA requires a computer that meets the meager Arduino system requirements. You will need to do some light copy/paste style Arduino programming following step-by-step instructions (covered in the programming guide below). Once VGA4EVA is programmed to your liking, there is no longer any legitimate use for the computer, and you may feel free to drop-kick it through a window of the corporate entity of your choosing.