by tomthefnkid
typedrummer
Teufelsberg
An acoustically interesting dome in an abandoned spy station at the highest point in Berlin.
We ran into flutist Thomas Von Der Brücke in the woods around Teufelsberg. Thomas has often recorded and performed in the dome. He invited us to come along for a tour.
Thomas on Flute…
Thomas on vocals and flute, with me on percussion
Photographs by Rebecca Zicarelli
Glacier Sounds
Overlapping loops of varying duration to represent natural cycles.
In October I collaborated with Wade Kavanaugh and Stephen P. Nguyen to compose and perform the sounds of a glacier for their installation at the Gem theatre in Bethel, Maine. The glacier was made from paper.
Wade and Stephen:
A time-lapse video of the project:
A time-lapse video of a similar project they did in Minnesota 2005:
The approach was to take a series of ambient loops and organize them by duration. The longer loops would represent the slow movement of time. Shorter loops would represent events like avalanches. One-shot samples would represent quick events, like the cracking of ice.
It took several iterations to produce something slow and boring enough to be convincing. I used samples from the Ron MacLeod’s Cyclic Waves library from Cycling 74 https://www.ableton.com/en/packs/cyclic-waves/. Samples were pitched down to imply largeness.
Each vertical column in an Ableton Live set represents a time-frame of waves. That is, the far left column contains quick events and the far right column contains long cycle events. Left to right, the columns have gradually increasing cycle durations. I used a Push controller to trigger samples in real time as people walked through the theatre to see the glacier.
The theatre speakers were arranged in stereo but from front to back. Since the glacier was also arranged along the same axis, a slow auto-panning effect sent sounds drifting off into the distance, or vice versa. Visually and sonically there was a sense that the space extended beyond the walls of the theatre.
In the “control room” above the theatre… using Push to trigger samples and a Korg NanoKontrol to set panning positions of each track:
The performance lasted about 45 minutes. Occasionally the cracking of ice would startle people in the room. There were kids crawling around underneath the paper glacier. Afterwards we just let the sounds play on their own. A short excerpt:
Photographs by Rebecca Zicarelli.
Motorized potentiometers
And other ways to remotely control existing dials.
Suggestions from robotshop.com: http://www.robotshop.com/forum/post-p101569
Motorized potentiometers
from p3america: http://www.p3america.com/motorized_potentiometers_text.htm?gclid=CJSetfSYusUCFdOQHwodPEUAaw
From Online Controls: http://www.onlinecontrols.com/mpots.htm
Motorized faders
Sparkfun motorized fader (like the kind used in DAW control surfaces) https://www.sparkfun.com/products/10976
Servo control and sensing
from electronics stack exchange: http://electronics.stackexchange.com/questions/60272/servo-controlled-potentiometer-using-rotary-position-sensor
notes
The Potentiometer Handbook by Carl David Todd: https://www.bourns.com/pdfs/onlinepotentiometerhandbook.pdf
Google search: servo to turn a knob
Shower temperature control from SmithyTech: http://smithytech.com/?p=5
Arduino HVAC Servo Thermostat/Controller by tikka308: http://www.instructables.com/id/Arduino-HVAC-Servo-ThermostatController/
What kind of motor would I need to turn this central heating valve? http://electronics.stackexchange.com/questions/97269/what-kind-of-motor-would-i-need-to-turn-this-central-heating-valve – observations about the difficulty of using robots to turn knobs
Sous vide cooker with feedback control: http://www.nerdkits.com/videos/sous-vide/
Homemade Electric Telescope Focuser: http://emediadesigns.com/focuser/
Use your Raspberry Pi to move parts of a robot or control anything that can rotate – by Rob Zwetsloot http://www.linuxuser.co.uk/tutorials/control-servos-with-a-raspberry-pi
The sun is now virtually blank
“…In the weakest solar cycle in more than a century.”
“Not since cycle 14 peaked in February 1906 has there been a solar cycle with fewer sunspots.”
At Vencore Weather
Substituting components in parallel
Resistance and capacitance in an AM radio.
A first test to find out if its practical to ‘piggyback’ external controls on to an existing radio. The reason for doing this is to leave an original radio intact by clipping the remote components to the leads of the existing controls.
For example a varactor would be connected in parallel to the variable capacitor already in the circuit. The existing capacitor would be set low. The capacitance of the varactor would then be added to the total, using the formula for parallel capacitors.
For potentiometers, its not as easy because parallel resistors are divided:
Formula: Rtotal = R1×R2/(R1+R2)
For example if R1 is 10K, R2 would need to be 100K to get a total resistance of 9K. To get 99% of the existing resistance, the piggyback resistor needs to be 100 times the value of the existing resistor. 1 MegOhm if matched with 10K.
Practical considerations
What happens when the radio is not being controlled remotely?
- For capacitance, the remote capacitor (varactor) should be set to 0.
- For resistance, the remote resistor should be set as high as possible.
Conversely, how should the physical controls on the radio be set when operating remotely?
- Variable capacitors should be set as low as possible.
- Potentiometers should be set as high as possible. For a volume control this actually means turning the volume all the way down.
Switches
SPST switches can be considered as a form of potentiometer with infinite resistance. A piggybacked switch will only work if the existing switch is in the ‘off’ position. And vice-versa.
Double-Throw and Rotary switches present more difficulties as multiple states are maintained by the same device.
I don’t think multiple throw switches can be piggybacked. Two possible solutions:
- mechanical connection to manual control (servo)
- internal relays – requiring modification of the radio, so that the existing control and the remote control operate the same relays
- Hybrid approach: Operate the switches manually while operating other controls remotely.
Testing
I piggybacked a tuning capacitor from an AM radio onto the tuning capacitor of a vintage Radio Shack Globe Patrol (regenerative receiver).
Regenerative receiver design
Notes and circuits
“The regenerative circuit (or regen) allows an electronic signal to be amplified many times by the same active device”
From Wikipedia: http://en.wikipedia.org/wiki/Regenerative_circuit
In other words it uses feedback.
Charles Kitchin, N1TEV
“High Performance Regenerative Receiver Design”, QEX Nov/Dec 1998: http://www.arrl.org/files/file/Technology/tis/info/pdf/9811qex026.pdf ”
A Shortwave Regenerative Receiver Project”, http://www.electronics-tutorials.com/receivers/regen-radio-receiver.htm
A two part video presentation: https://youtu.be/gcr7hSjTqd8
Google search, kitchin regenerative receiver, https://www.google.com/?gws_rd=ssl#q=kitchin+regenerative+receiver
Derivatives
- Steve Yates, “Regenerative Receiver”, http://www.aa5tb.com/regen.html
- Cliff Donley, http://n9sja.com/2012/11/15/k8tnds-take-on-the-kitchin-regen/
- N9SJA, Varactor Tuning, http://theradioboard.com/rb/viewtopic.php?t=4706
Makota, 7N3WVM
- website: http://www.qsl.net/7n3wvm/
- receiver: http://www.qsl.net/7n3wvm/regen.html
Derivatives
- From QRP-Popcorn, by Todd, VE7BPO http://qrp-popcorn.blogspot.com/2015/02/regenerative-receiver-4.html
- Dave Richards, “The Sproutie” https://aa7ee.wordpress.com/tag/charles-kitchin/
- Dan Wissell, N1BYT, “The WBR Receiver” http://pe2bz.philpem.me.uk/Comm/-%20ARRL/Build-Service-Design/Receivers/TheWBR-BetweenRegen+Direct/0108034.pdf
“… the design virtually eliminates the negative aspects of regenerative receivers such as antenna radiation, frequency pulling, micro- phonics and hand capacitance effects.” Ironically these are the features I am looking for.
Circuit Salad
By Ray Ring
- http://circuitsalad.com/2012/09/30/a-high-performance-regenerative-radio/
- http://circuitsalad.com/2014/12/06/another-excellent-performing-regen-circuit-coming-shortly/
- http://circuitsalad.com/2015/01/27/yet-another-variant-of-the-junk-box-regen-this-one-is-really-weird-but-is-an-excellent-performer/
More…
- DXZone: http://www.dxzone.com/catalog/Technical_Reference/Receivers/Regenerative_Receiver/
- archive.org, regenerative receiver, https://archive.org/search.php?query=regenerative%20receiver
- Google search, regenerative receiver design, https://www.google.com/?gws_rd=ssl#q=+regenerative+receiver+design
- Ramon Vargas Patron: http://www.zen22142.zen.co.uk/Circuits/rf/swr.htm
- Small portable regenerative receiver by PA2OHH: http://www.qsl.net/pa2ohh/03rega.htm
The story of television
1956 RCA Educational Documentary
By WDTVLIVE42
https://youtu.be/qhqtByYjmPY
ep-426 Interactive Video – Spring 2015 week 14
Jitter programming
Developing with javascript, gen, and external objects.
Javascript
Jitter in javascript: https://reactivemusic.net/?p=19218
Gen
Jitter gen: https://reactivemusic.net/?p=19205
Particles
https://reactivemusic.net/?p=19194
Jitter objects
Writing Jitter external objects: https://reactivemusic.net/?p=19208
Revisiting Vizzie
Even after all that, Vizzie is my first choice when starting a project or building a prototype.
Vine analyzer example:
https://github.com/tkzic/max-projects/tree/master/maxvine
patch: maxvine-analyzer.maxpat (requires other files in the maxvine folder)
More analog video
media converter demo: https://reactivemusic.net/?p=19173
Miscellaneous
And topics that didn’t get covered.
Algorithmic video and data visualization
- D3 (javascript) http://d3js.org
- AARON by Harold Cohen https://reactivemusic.net/?p=17778
Projection mapping
Cornerpin: https://reactivemusic.net/?p=11838
Lighting control systems
DMX: Andrew Pask tutorial: https://reactivemusic.net/?p=18266
Development tools
- HTML5 Canvas https://developer.mozilla.org/en-US/docs/Web/API/Canvas_API
- WebGL http://en.wikipedia.org/wiki/WebGL (Unity)
- WebRTC: http://www.webrtc.org
- OpenFrameworks http://openframeworks.cc
- Cinder http://libcinder.org
- Quartz composer http://en.wikipedia.org/wiki/Quartz_Composer
Miscellaneous
60 minutes of whales: https://reactivemusic.net/?p=8433
Assignment
Do something.