Wednesday, 18 December 2013

Cellular Automata & Music

Much of the primary research into cellular automata (CA) was carried out in the 1940s at the Los Alamos National Laboratory in New Mexico, USA. by Stanisław Ulam and John von Neumann.

They were studying crystal growth and of all things, self-replicating robots.

The picture of the above shell is of a Textile Cone or the Cloth of Gold cone. It is a venomous species of sea snail. The colour pattern of its shell resembles a cellular automaton named rule 30

And of course above we have some terminators.:-)

So what has all this got to do with music?

Well, CA exhibits the properties of reproduction and evolution which can readily be observed in nature (and in self replicating robots). Rules 30, 90 & 150 appear to be of special interest among many researchers when applied to music as they produce complex evolving patterns from very simple rules.

Above is panel # 9 from my NLC (Nonlinear Circuit) synth. (The case is under construction at the moment).
It's a analog sequencer based upon the principles of CA.
In 2014 I should have it fully up and running.

There are basically 6 cells/ sequencers. They produce 18 different CV patterns that can be
simple or very complex.

The cells can either be isolated or they can be made to affect their neighbouring cells/sequencers.
You can do this by patching from one into the other/s.

The blue sockets are inputs, and the red outputs.
The the top blue socket on each cell receives the clock (which can be from the same
or a different source). A clock divider will make each cell run at a different speed.
The blue sockets below the clock(CLK) , labeled left & right receive gates.
CVs from each neighbourhood can be summed or subtracted from others.
Here is the user guide.

The sequencer is primarily designed to operate a Serge synthesizer (or a NLC synth) but as most
of my Serge is currently under restoration I've have to test it with a Buchla.
It's interesting though I'm looking forward to testing it with my Serge in 2014.

Here are a few more examples of CA applied to music:
The Nintendo DS (with the R4).

And a Novation Launchpad:

Monday, 16 December 2013

The David Morley Serge

This Serge is a very early example of a "paperface".
It was probably built by CalArts university students in the 1970s.
 They were most likely supervised by Serge Tcherepnin himself.

(Correction: recent info has come to light that this was built by Peter Davidson in the 1970s)

Ken Stone has more pictures of this synth in his CGS Gallery

In this video David Morley talks about it around 3.50 mins.

I purchased this synthesizer from David Morley in mid 2013 & have placed its' restoration
in the very capable hands of Ken Stone.

The wooden case has 8 compartments.
The top two house the reverb & power supply.
The lower six house the 6  paperface panels:

The top left panel contains the filters, reverb, phasers & a mixer.

The next panel on the left contains a heap of ring modulators, gates, a negative slew, an ASR, and a bi-directional router.

The bottom left panel is the famous Sherman Chaos bank. Ken and I are debating whether to leave the bare metal alone or to add new artwork. 

The top right panel consists of a noise source, a random voltage generator, triple wave shaper, +ve & -ve slews and a envelope generator.

The middle right panel consists of 4 oscillators, comparator, a send/receive & a mixer.

The bottom right last panel contains two programmers & a sequencer.

Buchla ASR - Verbos 263v

I love my euro  & Serge ASRs (Analog Shift Registers) so why not one for Buchla.

This arrived today.  The Quantizer is just icing on the cake.
Looks like the outputs from the ASR can be plugged into the quantizer inputs with 
standard Buchla shorting bars.
Thanks Mark. :-)

Rotary knobs to set scales. Very nice.
So what's a ASR ? Well it's like a Sample & Hold plus one (or 4 in this case).
The ASR samples a CV for every pulse received.
On the first pulse, the sampled CV appears at output 1.
On the 2nd pulse that CV is moved (shifted) to output 2 & a new CV is sampled for output 1.
On the 3rd pluse, the CV at output 2 is shifted to output 3, the CV at output 1 goes to output 2,
and there is now a new CV at output 1.
And so it goes on.
Ken Stone has a ASR PCB which I have been building:
It runs on +-15V. Should be a perfect addition to the Buchla.


Sunday, 15 December 2013

Elektron Analog Four / Octatrak with 2 Buchlas

Here is a video of two of my Buchlas with some Elektron gear.
I totally love the Analog Four.
It's ability to sequence virtually every drum machine & synth I own is incredible.
Serge, Buchla, Roland.... nothing stands in its way.

Modules used are:
(System 100): 180,158,144,123
(200) : 257,281,258,259,207
(200e): 281e,292e,251e

The 251e is the main sequencer in this piece.

ARP Modular Synthesizer Lab (MSL)

The ARP  Modular Synthesizer Lab was a true modular synth in every sense.
It consisted of small self contained bakelite boxes housing everything from VCOs & filters to multiples & envelope generators. These were all battery powered (9V DC).
Aimed at the school market they were sold with a teacher's manual.

They are regularly described as a "poor man's" ARP 2600/Odyssey because many of these circuits were found in those synths.

These modules are extremely rare today.
My collection includes:
The MSL keyboard
Speaker/Amp (Model 1511)
Multiple Box (Model 1510)
ADSR Envelope Generator (Model 1501)
VCA (module 1509)
VCO (modules 1504) x3
The mixer/atenuator (Module 1508)
Noise(module 1503)
sample-and-hold (module 1507)
Ring Modulator (Module 1505)

I'm missing the filter.:-(

More pics:

The sliders are pretty stiff. Needs cleaning and lubrication as with much of my old ARP gear.

 The Bakelite case:

I'm on the hunt for the MSL teacher's manual and the filter. If you come across either please contact me.