Choreographable Video Synth

This circuit is a next version from the video synth. 

Some ideas from how this installation could look like :

Messing around with my last synths, here are some circuits that I want to be able to reproduce with my new synth :


Here are some ideas of how the circuit could take form :

A Nintendo gameboy catridge teardown :

Some sketches of possible configurations :


I am currently splitting the project into two parts : 

PART 1 : A series of independent transforming modules, VGA IN/OUT with screens, and oscillators with patch cables.

PART 2: A board called palímpsêst.OS which is a rack (or archive) of several 16MB memory modules. 



Each memory will share the same power (5V, 3.3V, GND), timing CLK signals, control signals (to enable/disable counters, buffers, RAM, ADC etc. and to RESET things). All this can be automatically controlled by an microchip which can turn on/off these memory banks individually in time. Despite this there will be basically all the components on the board to make it function independently and, most importantly, test and debug it’s functioning. 

Just like for the previous memory board, the following parameters will be modifiable :

  • the duration of the recording and playback,
  • the sequencing of addressing this memory,
  • the amplification of the incoming and outgoing video data,
  • the sampling rate and sampling pattern of video recording and playback,
  • the bit resolution of the recording and playback,
  • the continuity of the above processes or the frequency of their interruption

I have corrected the errata from the previous 16MB memory board, removed jumpers (as this board will be made by JLC PCB), added a ground plane, made it more compact (by removing the burst record functionality, level shifting, and having two layers). I also added a battery so that memory is persistent as long as the battery has juice. The main work however has been breaking out pins to a bus which can be controlled by a microcontroller. There is now the possibility to have 3 memory boards A,B and C, and to control their recording and playback, and all the parameters of these two things that can easily be controlled, in time. 

With these boards it should be possible to take an input, record it, then play it back and mix it with the input through a feedback pot. Because this can be done by three memories, they can also record their respective outputs and layer without any mixing with the VGA . 


01/12/2022 UPDATE :

So far debugging: For some reason the ADC is not spitting out anything, regardless of what I feed it. I changed the input op amp and it had no effect. Previously to soldering the ADC everything seemed to be working…As far as I can tell the memory is working and all the bias pots too.


-Should have an input pin and 5V pin for testing on board.

-I should add the right footprint for a big capacitor at the input of the ADC (I forgot and put a 0.1uF which didn’t work).

-I should take the classic gameboy battery footprint.


Realizing that this whole massive multi-module thing could be made with just one memory module having feedback !!! That or a simple echo IC like this one I ordered (BU9253 : ) :

That said the delay is only 8Kbits and it’s designed for audio.


Analog Functions Board :

Trying to remake the previous analog functions board but at JLC and as pro-style as I can. The general idea is to make a bunch of op-amp circuits that modify video in various ways and that can be combined with the logic modification board to make a completely full suite of electronics video transformations. Not sure yet how they could be automated.

Fixes from previous esceptionally newbie laser engraved version :

  • +15/-15V supply for all the op-amps using the handy ICL7660 negative voltage generating IC will hopefully solve many issues.
  • Using normal general purpose op amps in addition to super fast video ones 
  • Having bias pots at the inputs and outputs to sort out any different in offsets. 
  • Doing more research to get better circuit designs, notably looking at the Analog Thing, The Hackaday Logic Noise Series, Rod Elliott’s active op-amp series.
  • Making things less noisy with : seperated AGND and DGND, caps near op amps, following suggested board layouts, 2 sided board with GND plane (!)
  • Tying to take into account impedence matching with 75ohm VGA camble at the input and output and testing a specialized video line driver IC
  • Making op amp board with the possibility of automating thier switching / pot levels ?
  • Adding over-amped fuz circuit, phase-shifter, and various filters (LP, HP, BP, Notch), and adding a reset to the integrator circuit. 

I think the theme of this board, especially seeing as I have 25 of these TL074 op amps, is showing the diversity of flavours (and range of sometimes exotic circuits) of the history of op amp filters, arithmatic, etc. circuits. I plan on highlighting the names (and dates?) somehow.

The idea has clarified now, it will be a grid of 24 different op amp circuits in a 6 by 4 grid with the name of each circuit and a letter/number identifier. At the top will be all the power, VGA in out and bias amps.

I collected the circuits from various places (AoE among them) but especially from Rod Elliott’s write up on active filters (which you can access with Internet Archive) :

I am most excited about the combination of digital and analog – like in the switched cap filter, sample and hold, resettable integrator, and demux amp circuits. Being able to modify the functioning of am amp with digital signals (even with a tunable capacity and voltage controlled potentiometer) seems to offer really cool potential. This being combined with SRAM could be a really cool composite project.


Notes from Museum visits :

Composite (wood, porcelaine, gold) in flat, relief, and form of object.

Could I have both feathery frilly fuzzy video mixed with crisp solid geometric form to create similar layering ?
Some video noise looks like different types of stone
Rococo / Baroque video ?
Decorative video?
High quality video / image capture ?
Once I’ve finished with this round of tools, I have to compose more !!

Can I mirror an image half way to make a Rorschach like ink splot ?

Wicker chair silhouette series, pumpkins 
Some format of showing the circuit and the output that can end up in a book
Shoot my own video to mess with


Flow vs. Choppiness
Look at Photoshop for 
Roughness, relief 
Edges versus centers 

Movement vs stasis 

Enriching of detail possible ?
Abstracting, cosmic making
Fine lines versus coarse
Color fields
Deep friedness
Films of cows, ocean. Stills of still life? Flowers, birds, drapes folding, mold, fruit, bones
Color mixing vs melting vs meeting
Paint viscosity (runny vs clotted)
Direction of brush strokes 
Focus direction in canvas
Translucent flesh, shine vs glow from interior, waxiness 
Composition, color pairings and form
Foreground displaced to background vice versa 
Meeting pattern planes 
Lighting and shadow
Illusion of depth
IDEA : I could take a file, put it into the memory, and then “play” it different ways (because the width is completely arbitrary below). A file could thereby become a pattern, or a long abstract video, 

Windows PE visualization


Or I could put an image onto a floppy, then damage the floppy, and show how it would modify the image ?