By vb, 31/12/2014

Some time ago there was a discussion on the MaxMSP-forums going on about recreating a specific chaotic oscillator. Actually it goes back to this site: ciat lonbarde, where you can find different sorts of “intuitive analog organs for your atonal/chaos squishing needs” as Peter Blasser, the creative mind behind all this, says.

The website is weird and the instruments are beautiful, so this got me interested.

There is some more information buried there about the “fourses” oscillator which is, well, pretty idiosyncratic and a little mysterious… This is what I think is meant:

  • The oscillator consists of 4 ramp generators – at one point he calls them horses – so four horses make a fourses 🙂
  • Each generator has a frequency for ramping up and a frequency for ramping down,
    and it has an upper and a lower limit.
  • The generators are basically stacked above each other, without the ramps crossing, but bouncing back when they meet, i.e. the upper and lower limits are set by the neighboring generators.


vb.fourses~ScreenshotI tried recreating this in MaxMSP and ended up coding a little external that does all this (can be found in the Downloads section). Of course this is a digital solution and thus, especially at high frequencies, suffers quite a lot from aliasing.

You can listen directly to the outputs of the 4 ramp generators or use them as playback pointers which read from a wave table or sample buffer.

Here is short example, where the four output ramps are mixed into a stereo file:

And here is a little  example where fourses granulates an audio snippet of Cage’s prepared piano:



One Comment

  1. Riccardo Santalucia says:


What do you think?

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