Saturday, 30 August 2014

Comdyna - The Analogue Computer music setup for CELLDYNA

A bunch of pictures and a brief bit of background on the Comdyna GP6 I used for the track CELLDYNA on my Automata 49 album ==>

For CELLDYNA I used minimal analogue computing elements (2 to 4 integrators, 2 potentiometers and an inverter) for direct sound synthesis from the GP6, hybridized with a digital Cellular Automata sequencer driving various different synths for the drum sounds.

The spoken word samples are from a 1969 lecture from EAI titled "Understanding the Analogue / Hybrid Computer". In order to use such a small amount of computing elements I setup a fairly messy chaotic style feedback patch. I did this intuitively pluging around to see what happens on the scope while listening to the output in realtime. This approach worked well for this track, and enabled me to get quick results without resorting to theory. I made a bunch of recordings during Dec 2008 & Jan 2009, which I then edited into the final track.

Comdyna GP6 & Oscilloscope - obligatory photo with the lights off to see the glowing lights better!

Comdyna GP6 & Oscilloscope
The complete EAI lecture was provided to me by my friend Bernd Ulmann (Vaxman), originally digitised by Christian Peters, and I sorted through it to sample a number of interesting segments. The lecture is also available on the web, check it out here online in the library at Bernd's incredible computer museum. Below are a few slides from the lecture itself. You will also find in Bernd's library a bunch of scanned Comdyna information that I contributed, including the GP6 operators manual.

Slide from EAI Understanding the Analogue/Hybrid Computer Lecture (Courtesy of Bernd Ulmann)

Slide from EAI Understanding the Analogue/Hybrid Computer Lecture (Courtesy of Bernd Ulmann)

Slide from EAI Understanding the Analogue/Hybrid Computer Lecture (Courtesy of Bernd Ulmann)

Here are some more pictures taken during the CELLDYNA recording session. My GP6 came all the way from the University of California, so I needed to tackle up a rather hefty and dangerous looking 240 to 110v step down transformer I dug out of my workshop.

Rear Panel connections from the GP6 to the scope and mixing desk, messy stuff... 

Close up of GP6 rear panel connections

Another close up of GP6 rear panel connections

My rather dangerous looking 240v to 110v step down transformer, better keep away from that...

Always best to program from a sofa

GP6 with all the leads out ready for patching