What is the Quantussy?

Quantussy is the name Peter Blasser gave to the cluster of five oscillators in his Cocoquantus.  He says,

The Quantussy is a five (5) petaled flower, each petal with oscirator, that creates a rhythm, that triggers quantizations of the movements of the other four oscirators.  The Quantussy is thus both based on five (5), but four(4)… and its name also refers to Quantum Physics through its unique “double quantizing” of angular momentum.

Running at low frequencies, the Quantussy is intended to provide ample modulations for the various functions of the COCOs, through inputs “FLIP”, “SKIP”, and “SP.AF”, or “Speed Affect”.  The Quantussy petals can also run at audio frequencies, as well as “Balcium” frequencies, depending on a toggle switch.

Why the Quantussy?

The purpose of the Quantussy is primarily to provide modulations for the two digital delays (COCO) in the Cocoquantus. However, the applications can go far beyond that use!

Generative Applications

I have an interest in generative music, automatically generated sounds that have the potential to seem as if they were intentionally composed, but in actuality are in some sense accidental, but not simply random.  The work of creating such sounds entails discovering, often by trial and error, the right combination of control and sound generating modules, and adjustments of their many parameters.  The Quantussy supports exactly this kind of exploration.  It does not use random functions!  But, since it uses analog components with slight variations over time, temperature, etc., it is not fully deterministic.  And this led me to build emulations of it.

I started digging into the Quantussy internals by studying the Cocoquantus schematic diagram.  I wrote a full post about that schematic.  Here, I want to focus on one main idea:  that of a cycle of five cross-modulating oscillators.  The Quantussy allows the cluster to be cross connected in many different ways, but the most interesting one is where the five are in a ring.  Each oscillator clocks two sample and holds.  One sample and hold is internally hooked to the frequency CV input of the oscillator.  That is, every cycle, the oscillator can change its frequency, based on a sampled control voltage.  The other sample and hold takes an external input and provides an output (Peter calls this the Castle).  So you can think of this as having a CV input, an oscillator output (triangle wave), a Castle input and a Castle output.  Roughly, like this diagram.

The Audulus emulation of this:

Picture five of these, arranged in a ring, with each Triangle output patched to the Castle input of the next, and also the Castle output patched to the CV in of the next.  The Triangle wave of the first is sampled by the next, and then passed on to the CV input of the following one.  In a ring.  Here’s the picture of it in the Audulus emulation.

The beauty of this arrangement of five is that the cross modulations spiral around, resulting in unpredictable, but somewhat repeating patterns.  I am not sure what the mathematical correspondence would be, but it can be fractal like.

The user controls consist of a three way range switch for each oscillator, a global initial frequency knob, and a global ‘chaos’ knob, which sets the modulation depth for all the cross modulations.

So fascinated was I by this design that I built the Quantisise, which is a six module analog emulation, that is fully patchable.  Explore that project with the Quantisise Tag.



2 Responses to What is the Quantussy?

  1. Meng Qi says:

    as a Quantussy expert with synth building experience like you, why not designing an instrument bringing a dedicated interface together with Quantussy?

    I look forward to it!

  2. Richard says:

    Meng Qi, isn’t the Cocoquantus already an instrument of this sort? At least the version one with the brass screws for touching. Touching was lost when Cocoquantus started having banana jacks.

    You, also, would be a great designer of such an instrument! What sort of interface are you thinking of?

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