Manual to put together:
Notis: A resistor labeled "0" is zero ohms, a piece of wire or scrap lead. Instruction sheets are 200 dpi.
Pretty Paper Rolls: Experiments in Woven Circuits
The top two panels contain the pulse-brain circuitry- the geometrical forms that I call rolls. They are three, four, five, and six-noded versions of the same simple transistor circuit (figure 2). They cycle impulses, inverting polarity at each node; imagine a pulse oscillator flipping at a set frequency. From this humble base whole montages can be built by connecting nodes to nodes on other rolls (figure 3). I abstract the rolls as polygons; a square is a four-noded roll as a pentagon is five-noded. Connections can contain a resistance which softly melds two nodes together; a connection without resistance creates a new monad node. During experiments with the rolls, I found an interesting difference between even and odd ones. Take a 6-roll (figure 4). The lozenges surrounding it represent the temporary state of each node, where white is inverse of black. Start on a black node and follow the arrows- the impulse ends as it started. The even rolls are stable and alone they maintain a certain periodicity. Now look at the 5-roll (figure 5). Start on the star and follow the impulse around- when you arrive on the start node now it is inverted. Odd rolls exhibit a “paradox spiral”; in attempting to resolve their states, they transcend periodicity and go into a sort of high-frequency chaotic trance. The combination of even and odd lead to rich experiments in pulse and periodic fuzz-burst.
Meditating on the oscillographs of my experiments, I realized I should design filters, or translators, to bring the odd ultrasound/radio blurps into audible range as well as work with the low frequency even pulses. The bottom three panels of my Rollz-5 (figure 1) each contain four of a kind of translator. For simplicity’s sake, I allowed one input node and one control knob for each translator. By abstracting the most important feature into one control, learning and controlling it is easy. On the first translator, an “Ultrasound Filter”, the knob sets the cutoff frequency around which ultrasounds are reflected down to audible range. It uses a switched capacitor filter, which has a (happy) side-effect of heterodyning high frequency sound by its reference tone. In figure 6, the top trace shows mostly odd-roll chaotic ultrasound, and the bottom shows a translation. It sounds like an old-time radio as it sweeps through stations; there are audible difference tones swooping up and down. This translator also filters the timbre of the even pulses.
The second translator type is called “Gongs”. It works with even pulse material, waiting a period set by the control knob, then pulsing a resonant filter preset to a certain pitch and damping. Normally I would desire moveable pitches, but I reconciled with set pitches because this is a drum machine- The tones mark phrases around which melodies develop externally, and I would rather control the phrase length than the tone of the gong. Anyhow, a creative hacker could easily mod these circuits to make the pitches moveable. Figure 7 shows an even pulse rhythm on top, and a gong translation on the bottom. The sonic effect is anything from a short woodblock tone to a long deep resonant gong, synchronized at short or long periods.
The final translator type is called “Auto VDog”, which uses the same resonant filter as Gongs, but at a very low frequency, to transform pulses into a slow undulation. This undulation controls the amplitude of a simple drone tone, to make a ghostly complement to the pulse material. Figure 8 shows the raw pulses on top, and the translation on bottom. I created this translator to balance with the plucked and pulsed sounds. It’s like sending pulses through a watery wave-tank which speaks a simple tone, a complement to the more abrupt rhythms of the other translators, yet it relates periodically because it is based on the same raw material.
Here is a romanticized poem I wrote about the process:
"The Agamemnon Computer"
|FAQ for the rollz-5:
1.)The box was plenty big so I decided to swap pots for the X and Y resistors on the gong and AV Dog filters. I'll probably use a resistor to restrict the range of the pots closer to your suggest recipe values. My question is: Do I need to ground the unused lug on the
SSeems like you got a good handle on things. You don't need to ground the unused lug. In fact, don't. Because you are using the pots in this instance as variable resistance, they are to be treated as two terminal components.
2.) While building the pulse generators I noticed that the 1µF cap in the 6-Roll circuit is inverted compared to the other Rollz (ie. the neg leg is wired to the +9v.) I was surprised because I thought they were all variations of the same circuit. Is this on purpose?
NNo, actually you are right, this is a little bug in that it probably won't screw up operation that much. But yes, try to reverse the power conditioning capacitors on 6-Rolls from what it is.
DogslitThe Dogslit is an audio instrument designed to work with or without the Conrad 5000. It combines 2 touch sensitive slit-drums with 8 swoop-gesture modules and, in the center, a versatile two voice analog-warmth synth called the Dogvoice. These modules are part of a menage called..
The Conrad Papers
I originally intended to control the light box with some slow triangle forms, and the circuits evolved from there.
The Piezo Preamp adds an element of touch. If you embed a piezo in a suitable surface, such as the slit-drum (which isolates the vibration from other piezos), you can make pulses by lightly tapping it there. The preamp adds a decay to them as well as creating auxiliary pulses. There is a compliment to the Preamp, appropriately called "Antipreamp", which creates an inverted signal.
The most common cell is called "Swoop", which is so named because it creates a simple up-down gesture, with pulses to mark its middle and endpoints. It is triggered by pulses (at their * node) and also create pulses (at their + node). Each puts out a triangle after triggering at the * node, and each receives a control voltage at the + node. So you see, each of the two nodes is both input and output, dealing with pulse as well as DC voltages. The condensing of nodes is important to make (re)patching the multiplicity into an intuitive affair, and it emphasizes a strong Yin-Yang nature. To compliment the Swoop, there is an Antiswoop, which is a simple inversion of its gesture. Swoops and Antiswoops can be chained together in any combination, looped, woven, and triggered by Preamps or Antipreamps.
With a strong gestural basis, I realized an audio manifestation is important to compliment the lux manifestation; hence, "Dogvoice". It actually has two voices within it, and each one has four knobs. Each dogvoice has two primitive high frequency PUJT oscillators, one fixed and one variable. They are heterodyned to make low frequency tones. And then there is a ladder low pass filter, which has some controversy about its inventor. Some say Bob Moog did it and he certainly was smart enough. it also shows up in Arp designs, and there was legal action by Moog against Arp for this. This could have been similar to the Chowning/Yamaha/Buchla debate over "who invented FM synthesis?". Into the fray steps a Japanese man, Ken Takayama, who is rumored to have invented the ladder filter as well as FM synthesis. Anyway, the ladder low pass filter does a neat job, it has variable resonance as well as a subtle collection of quirks and squirts due to the non-linearities of the transistors. So in a dogvoice we have a very idiosyncratic radio heterodyne oscillator with volume control, and a squirky filter on top. It has four knobs: Pitch, Filter, Resonance, and Volume. It has two inputs: * modulates the filter, and + modulates the volume. Because of all its eddies and squirks, these inputs roll it through almost vocal sounds, hence its name, suggesting growls, yelps as well as the hisses and ultrasound ghosts a dog would hear in its dreams.
Philosophically this montage is intended for installations and longer performances where its dronal nature can become sumptuous. A darkened room responds to bongo taps as lights start to fade in and out. Two dogs growl in the corner. Dimensional transmution of standard living room.
Garçon demonstrates the second rollable version of the circuits, which he soldered in the Ciat-Lonbarde workshop.