MATRIXSYNTH: The HARMONOGRAPH SYNTHESISER & How to Sequence Your Eurorack System with a Record Player

Monday, August 17, 2020

The HARMONOGRAPH SYNTHESISER & How to Sequence Your Eurorack System with a Record Player

Lomond Ziggy Campbell

This one is in via Joshua. Links to additional info in the description below.

"I built an 18th century harmonograph and connected it to a 21st century modular synthesiser.

A harmonograph is an old scientific device that uses pendulums to create illustrations of harmonic motion, called lissajous figures. On this harmonograph each pendulum is connected to a sensor which triggers different elements of the synthesiser so that every time it makes a drawing, it also plays an accompanying synth soundtrack. There's also a contact mic on the drawing board to pick up the sound of the pen.

It uses three pendulums - two connected in a linear way to the pen and one rotary pendulum connected to the drawing board. You set them all swinging, lower the biro pen to the drawing board and let the pendulums run down over a period of about 5 minutes, after which both the unique drawing and soundtrack are complete.

I recorded an album of the first 18 drawings which can be downloaded from my bandcamp page:

You can see the drawings here:
I used proximity sensors and an Arduino to get the harmonograph talking to the synth. You can find the code, examples of drawings and sounds plus more information about the project on my website:"

And the optical record player:

MODULAR MECHANICAL REMIX of The Paralian by Andrew Wasylyk

"This is a kind of live remix made by mangling one of my favourite records through my modular system. I'm using a DIY turntable sequencer I built using an arduino. Here's a link to the video of how to make it - [below]

The record is The Paralian by Andrew Wasylyk. It's a cracker so go ahead and enrich your life by buying a copy."


"Convert any turntable in to a programmable rotary gate sequencer for modular #Eurorack systems with just a few components and a simple bit of coding.

- Control tempo with your turntable speed control!
- Sample from a record while staying in sync!!
- Build yourself two and beat match with dual turntables!!!
- Make your live #modular set more visual so thousands of people come to see you play instead of your three best pals.......TRUST ME!

x1 #Arduino Nano
x4 proximity switches / reed switches
x4 10K resistors
x4 3.5mm mono jacks
x4 LEDs (optional)
x4 100 Ohm resistors (optional)
x4 SPDT toggle switches (optional)
x1 vero board
.... + some camdenboss terminal blocks if you're in to that kind of thing.

Here's the link to the code, schematics and diagram:

For my device I used some flush cable proximity switches I got from a lab clear out. They're no longer available but this is pretty much the same thing:

The neodymium magnets I used are 4mm diameter by 2mm deep and any mild steel sheet metal will do for the plate.

I included some LEDs in my circuit as visual indicators plus some toggle switches so you can mute each channel, but neither are necessary."

1 comment:

  1. More recognizable to later 20th Century kids as the Spirograph.



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