The Magnetic Table : A CV controller for Modular Synth



Speaking of weird CV controllers:


yes i know it, allready post here

yes excellent !


I can’t really see, but are there potentiometers like in a joystick at the top of the moving rod (which can be used to control external oscillators)?

It seems so, yes. I don’t how it can be done other way

I saw this and my first thought was that it would be better to have a simple vice hold at the top, and that maybe the gyro chip I bought earlier this week could sit on the bob of the pendulum. Even better, a Bluetooth link would obviate the need for extra wires.

He has some more details on his website:

Apparently it’s just a two pot joystick mounted upside down with a custom shaft. The detail photos on the website also show that the magnets are actually stacks of various sized magnets he changes to control how much each stack attracts/deflects. Pretty slick!


Amazing! looks like just the sort of thing Sam would do a video on.


Those neodymium magnets sound like heaps of finger-nipping fun so I ordered some. I’m still interested in using a gyro chip and Bluetooth all connected to an Arduino nano or something similar. Add a couple of coin cells, and a magnet or two, and dangle it over a magnet table by a thin thread and it ought to generate some very interesting signals. For bonus points add a magnetometer.

Plus, multicoloured LEDs. Light show synchronized to your audio output!


I’ve got all the gear I need for my ideas now (magnets, thread, microcontrollers, gyros and Bluetooth transceivers) but not much time and energy. Nevertheless I did have a few spare minutes this evening to play with a simple pendulum magnet and a fixed stack of magnets, all identical neodymium discs. I got some really promising damped oscillation sequences before the thin synthetic thread snapped. So why don’t I use copper wire instead of fragile thread? Hmm, instead of using complex electronics and microcontrollers why don’t I just sample the induced current in the wires?

This has great potential. Sinusoids galore.


Fascinating. I hope you find/make time to pursue this!

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Yes, first guess is that I could replace the thread with wire (I have “conductive thread” wire from an old Arduino Lilypad wearable kit which may be just the right gauge) and stick a high value capacitor above the pivot. The induced current in the pendulum thread will show as a voltage fluctuation on the other side of the capacitor, and I just need to amplify that without too much distortion. A limitation here is that the two orthogonal signals you can get from the gyro or the joystick armature are reduced to a single signal.