Joined: Jul 07, 2007 Posts: 2081 Location: Berks County, PA
Audio files: 90
Posted: Sat Nov 28, 2015 2:29 pm Post subject:
Feedback instruments / no-input mixer / zero-input mixer Subject description: Feedback instruments / no-input mixer / zero-input mixer
Attached are some interesting articles / papers from 2002-2005 on feedback-driven musical processes from Knut Aufermann's writings page, including a copy of *Resonance* that is entirely on feedback.
Joined: Jul 07, 2007 Posts: 2081 Location: Berks County, PA
Audio files: 90
Posted: Sat Nov 28, 2015 4:52 pm Post subject:
robsol wrote:
Wow, thank you Dale! Leafing through these now, looks like essential reading for me.
My pleasure. I have another post coming up after finals on a different topic. Been running into some interesting stuff lately.
This one got triggered after my son Jeremy told me that Googling "zero input mixer" gave our electro-music 2012 performance video as the first hit. He was part of that performance.
I then tried Googling "no input mixer" and ran into discussions that led, eventually, to these docs. Enjoy! _________________ When the stream is deep
my wild little dog frolics,
when shallow, she drinks.
Joined: Jul 07, 2007 Posts: 2081 Location: Berks County, PA
Audio files: 90
Posted: Sat Nov 28, 2015 5:37 pm Post subject:
PS: My wife ordered me one of these for more Zero Input Mixing, for my 61st birthday last Tuesday, should be here this week. Jeremy and I were searching for likely candidates with features specifically for ZIM. He tracked this one down.
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AXS-10 front
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AXS-10 back
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_________________ When the stream is deep
my wild little dog frolics,
when shallow, she drinks.
Joined: Jul 07, 2007 Posts: 2081 Location: Berks County, PA
Audio files: 90
Posted: Sun Nov 29, 2015 9:25 pm Post subject:
Subject description: David Lee Myers
I've gotten through the David Lee Myers (a.k.a. Arcane Device) article in that Resonance magazine, found it so good that I tracked down a more recent interview from March 2014.
Quote:
Arcane Device has been your main vehicle and what people know you the most for, how did the concept for AD come about? What was the inspiration for the feedback machines?
In 1986 I was very taken with the long digital delays that were being produced. I’d always loved the tape delay work that Terry Riley, Steve Reich, and Fripp/Eno had done, and ever since my first encounter with an Echoplex years before, delay technology had been a kind of holy grail for me. Now the tech was catching up and I experimented with Electro-Harmonx, Art, and Digitech units. Finally I settled on Digitech 7.6 second delays, bought four of them and set about to build them into a self contained console. Really I was looking to create the ultimate guitar looping rig, but while designing the layout I figured that I should make it as flexible as humanly possible. This resulted in, to my knowledge, the first “matrix mixer” ever created. Nowadays this seems more commonplace, but at the time it was unique - a mixer which could feed multiple effects and return their outputs to all others, plus themselves - i.e., feedback loops. As soon as I powered up the layout, I immediately discovered that I needed no input: the delays themselves created their own sounds. Thus the Feedback Music was born, and others dubbed my creation the Feedback Machine. Other such machines followed, flowered, and alas, died. The cycle of life, eh?
... and further on ...
Quote:
What are you currently working on and what are your plans for the future?
Every few years I break everything down and sell it off, or throw it out. Sometimes I’ve even been known to renounce music and art altogether. Perhaps it’s a syndrome of some kind? Maybe I simply set standards too high, I don’t know. But the impulse never goes away. In 2013 I was determined to produce a new Feedback setup, going through two separate failures. At the end of the year I finally succeeded, devising a hardware layout that satisfied me completely. At this time I’m working with it as much as I can, and also beginning to produce accompanying video work. I’ve done computer graphics for print media for many years, and now I’m finally jumping into motion, so I hope you will be watching!
There are links to his home site (top) and some Youtube video work (bottom).
I plan to do some serious digging. I have never been satisfied with any digital modeling of genuine acoustic instruments -- I enjoy playing virtual instruments, for example the physical models from Applied Acoustic Systems -- but I have never found a model of a good 5-string banjo. The digital models of acoustic instruments are shit, in my opinion. Purely virtual, digital instruments are fine with me.
However, having been playing ZIM for a few years now, I do believe I understand some of the unique aspects of analog or dual analog-digital synthesis, and I honestly believe the most unique aspect of all is quantum tunneling effect. One cannot fully model a quantum processor with a digital processor. I believe that quantum tunneling cannot be adequately modeled by a digital computer, beyond a certain coarse statistical grain. I want to pursue that perspective of investigation. Keep pursuing it, actually.
I am not opposed to putting digital processing in the feedback paths, but I do believe that analog transistor noise (a.k.a. quantum tunneling effect) is the sound source of choice, because of its intrinsic unpredictable, stochastic nature. Digital non-determinism is fundamentally pseudo-random. If you know the algorithm and the seed, there is nothing random about it.
Time, however, can introduce genuine non-determinism into digital processing, especially into multi-threaded digital processing, for example in race conditions. Observe that time (of the wall clock) is the most popular means for introducing an unpredictable seed into a pseudo-random generator, unless you know the algorithm and the exact time of seeding. So, maybe I'd better keep digital time in mind as well. _________________ When the stream is deep
my wild little dog frolics,
when shallow, she drinks.
Joined: Jul 07, 2007 Posts: 2081 Location: Berks County, PA
Audio files: 90
Posted: Sun Nov 29, 2015 10:18 pm Post subject:
Subject description: Co-tunneling current and shot noise in molecules and quantum dots
Co-tunneling current and shot noise in molecules and quantum dots -- a 2005 dissertation with some potential applicability to these matters (attached).
dissertation_thielmann.pdf
Description:
Co-tunneling current and shot noise in molecules and quantum dots 2005
Joined: Jul 07, 2007 Posts: 2081 Location: Berks County, PA
Audio files: 90
Posted: Tue Dec 01, 2015 7:05 pm Post subject:
In reading parts of the thesis (the last post above), I am forced to backpedal somewhat in my fixation on quantum-only sources of noise bootstrapping the audio feedback process.
I cannot copy text out of this PDF (password protected), so I took screen shots of 3 relevant paragraphs after searching on the string "classic". The electrical noise (in transistors & probably in "passive" components) may contain both classical (i.e., non-quantum) and quantum noise-generating mechanisms. They all get amplified going around the loop. Classical noise probably predominates.
Therefore, the inability of a digital algorithm to model this analog phenomenon adequately may not be due strictly to quantum noise generation, but also to hidden variables in classical, statistical noise generation such as thermal noise. The variables are hidden because there are too many variables in play to know and model, as in any complex (but classical) mechanism. I certainly don't propose that my 5-string banjo sounds employ quantum mechanisms. Digital modelers don't model acoustic instruments adequately because there are too many non-general variables in an instrument's sounds. Likewise with classical mechanisms for statistical electrical noise. Nevertheless, electrical noise remains a stochastic mechanism that a digital algorithm can only approximate. There is no need to invoke the quantum to get that digital infidelity from electrical noise. Hidden variables do the job.
I think there are two parts to this business.
1) How do you generate your initial "bootstrap noise"?
2) What do you do with it, going around the feedback loop?
My shiny red mixer arrived yesterday. I was too tired to do more than a sanity check, but I did manage to get transient sounds like running a wet finger around the rim of a wine glass, that (if I could get them to persist) I'd like to use as a background pad.
I am thinking of extremely long duration delays, maybe by running the feedback loop through a ChucK or Supercollider or Kyma patch. The mixer has some delay FX of limited time span, but I start to see how, if I can get a minimal (very low amplitude) signal to stick around long enough going through a very long delay with sufficient wet-to-dry, I can get 2 forms of oscillation going, the short-term "second order bootstrap tone" (the "first order bootstrap" being the electrical noise that starts the whole thing in the first place), and a "third order sustaining tone" which is just the second order tone sustained around a very long feedback delay.
One other thought for now. You sometimes hear no-input mixing's feedback arrangement referred to (disparagingly?) as "just an oscillator," but as I recall, LC and RC oscillators do not oscillate fundamentally from noise in the circuit, but rather from out-of-phase charge-discharge timing of a capacitor in tuned combination with an inductor or resistor. So, I think ZIM-as-oscillator is somewhat different. While it can use RC or LC filters to tune the feedback path, the bootstrapped signal is due to statistical noise fluctuations being amplified and filtered, in CONTRAST to a capacitor being periodically charged and discharged in conjunction with an inductor or resistor. Anyone care to confirm or refute? That makes playing it much more unpredictable and sexy than a conventional oscillator.
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_________________ When the stream is deep
my wild little dog frolics,
when shallow, she drinks.
Joined: Jul 07, 2007 Posts: 2081 Location: Berks County, PA
Audio files: 90
Posted: Tue Dec 08, 2015 10:11 am Post subject:
Subject description: readings
I just finished the readings above. My next ZIM tutorial workshop will be much improved. Next performance too, no doubt.
The AXS10 will make its debut in the New Year's Eve webcast. The sweep-able mid-range eq is very useful for ZIM, as expected. The digital FX unit is very sophisticated, and a great complement to the more basic FX in my Yamaha portable ZIM mixer. NYE won't be a strictly purist ZIM set, but a good chunk of it will. _________________ When the stream is deep
my wild little dog frolics,
when shallow, she drinks.
Joined: Jul 07, 2007 Posts: 2081 Location: Berks County, PA
Audio files: 90
Posted: Sun Dec 27, 2015 12:01 pm Post subject:
I thought it might be instructive to look at some waveforms. I worked with low frequency pulses near the temporal boundary between distinguishable pulses and pulses that merge into bass tones.
This post shows the new Galaxy AXS-10 (the red mixer) with L and R saturated and the compressor fully engaged for my default.
I'll show the other mixers in posts below, so as not to run out of attachment space.
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AXS-10 pulse train approximates a clean reverse sawtooth
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Overdrive to add high frequencies. Note the asymmetry: The positives slopes have noise, while the negative slopes (including the drop to the trough, i.e., the "negative peak") do not.
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Compressors off on this. Now noise on both sides of 0, but note the lack of noise on the decay from the peak. There is also a second, semi-periodic beat in the right channel.
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Another without compressors. The right side second order beat is now a stable one-in-four.
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_________________ When the stream is deep
my wild little dog frolics,
when shallow, she drinks.
Joined: Jul 07, 2007 Posts: 2081 Location: Berks County, PA
Audio files: 90
Posted: Sun Dec 27, 2015 12:12 pm Post subject:
Subject description: Yamaha MG124cx
The Yamaha MG124cx, in comparison, has a basic pulse that begins to approximate a square wave, especially in the third pic, after turning off the compressors.
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Yamaha MG124cx basic pulse full compression
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Yamaha MG124cx basic pulse full compression + overdrive adds "bird squeaks", like the AXS-10 only on the attack above the 0 line, but not on the trough attacks.
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Yamaha with compressors off approaches a square wave even more.
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_________________ When the stream is deep
my wild little dog frolics,
when shallow, she drinks.
Joined: Jul 07, 2007 Posts: 2081 Location: Berks County, PA
Audio files: 90
Posted: Sun Dec 27, 2015 12:21 pm Post subject:
Subject description: Alto ZMX862
The little Alto ZMX862 is in a class of its own. Rather limited range of behavior due to lack of compressors or a second bus, and no FX (none of these pics use the FX units of the other two mixers), but it sure has a unique basic pulse and sound, with fairly good pitch range. It is especially throaty and interesting in the bass range.
All 3 mixers show asymmetry above versus below 0. Any ideas why?
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ZMX862 basic pulse train. The rising edge to the peak "above 0" actually has overtones that go + and -.
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Driving harder adds some squeaks. The fundamental "rising edge attacks" now generate overtones that completely swamp the fundamental pulse in both + and - directions, while the fall to trough is still a clean pulse. All 3 mixers show asymmetry a
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Cranked it up it the point where pulses have merged into a drone, essentially. Obviously different pitch on L versus R channel.
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_________________ When the stream is deep
my wild little dog frolics,
when shallow, she drinks.
Joined: Jul 07, 2007 Posts: 2081 Location: Berks County, PA
Audio files: 90
Posted: Thu Dec 31, 2015 10:06 pm Post subject:
Subject description: New Year's Eve 3-ZIM set
My New Year's Eve 3-Zero-Input-Mixer set (with post-processing in Live & also some electric banjo+ebow injected into a mixer feedback path in the middle section) is posted over here http://electro-music.com/forum/post-415491.html#415491 , along with some notes on the piece. Happy New Year! _________________ When the stream is deep
my wild little dog frolics,
when shallow, she drinks.
Joined: Jul 07, 2007 Posts: 2081 Location: Berks County, PA
Audio files: 90
Posted: Tue Jan 05, 2016 10:54 am Post subject:
Subject description: The Final Five
I played and recorded the attached The Final Five as a 6-minute extension to my 4:15 Electro-Music 2015 sampler piece Baby's Electro Castanets in early October, as a ZIM piece that Michael O'Bannon looked into visualizing for inclusion in the SEAMUS 2016 planetarium venue at Georgia Southern University in February. Unfortunately, their projector requirements were substantially out of the ordinary, so the video part of this piece did not come to pass.
This is a combination of standard ZIM and also computer ZIM. Computer ZIM feeds analog outputs of the audio interface box back to its analog inputs, and processes the signals in software (Live in this case, although I have worked with ChucK in this way, too), so the signal source is still analog transistor noise. I am adamant about not generating the primary signals using software, for information-theoretic reasons that I have posted above and elsewhere. I see this aesthetic decision to be the same as feeding purely acoustic instrument signals into the computer, rather than using inadequate models that approximate acoustic instruments. I have no aversion to primarily abstract software-synthesized instruments that don't pretend to be something else like banjos.
I remember editing various different ZIM recordings together into the first 4:15 for the EM2015 sampler. The added 6:00 was all live performance, I think. All 10+ minutes are in the attached file.
TheFinalFive.mp3
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The Final Five, copyright 2015 by Dale E. Parson, Creative Commons 3.0, distribute freely with attribution
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TheFinalFive.png
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Adobe Audition waveforms
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_________________ When the stream is deep
my wild little dog frolics,
when shallow, she drinks.
Joined: Jul 07, 2007 Posts: 2081 Location: Berks County, PA
Audio files: 90
Posted: Tue Jan 19, 2016 6:33 pm Post subject:
Blue Hell wrote:
Very nice track that last one!
Thank you, Jan.
I spent an hour last night playing around running an aux send from the red mixer through Live and back to the mixer, side-tapping the signal to mix it into Live's output. It was very interesting to put a graphic EQ in front of a granular delay, manipulate the granular to do some pitch shifting&filtering, and then *see the effect in the waveform appearing in the EQ, which sits before the granular in the chain*. I could actually see the feedback, in the sense that manipulating the "after effect" in the signal chain changes the display of the "before effect." Of course, in a loop, there is no before -> after relationship.
When I get time, I'll post a short youtube or vimeo clip and link it here.
I was getting some new sounds out of this, gas from a gas jet in a stove, wind, something that sounds like wind on a mic without a windscreen (pop filter), wind breaking tree branches. I'll post when the time comes.
Thanks for posting. _________________ When the stream is deep
my wild little dog frolics,
when shallow, she drinks.
Joined: Jul 07, 2007 Posts: 2081 Location: Berks County, PA
Audio files: 90
Posted: Fri Jan 22, 2016 7:31 am Post subject:
Subject description: Electro ZIM Fire
Here is a 12:39 workout Electro ZIM Fire that is an exploration of fire-like timbres. I fed the mono Aux Send from the red ASX-10 mixer into Live, through a graphic EQ, a grain delay, and a compressor. I used a simple delay before the compressor in a few short places in the 2nd half of the session. The EQ was to allow me to try to avoid excessive pops, especially in the high frequencies. The grain delay and the mixer itself were my main controls, grain mostly for pitch & somewhat for timbre. The compressor was a safety net to trap the pops. The output of that goes back to an input of the mixer, and a side tap takes it to the output of Live. The mixer runs an input through the usual gain, compressor, EQs, level slider, Aux level knob, and from there out the Aux send, completing the feedback path. I didn't use the main out or 2nd stereo bus of the mixer, nor any mixer FX.
I ran another signal path from the Yamaha MG124cx mono Aux send through an identical, parallel track in Live.
At various places this has sounds like a propane stove gas jet, a wood fire in the fireplace (complete with the sounds of crackling and the draft up the chimney), a forest fire, thunder, and some pure electro sounds. Runaway feedback got away from me a few times, so I edited those down to safe levels before posting. Waveforms & the Live channel appear below.
FractalZimFire21Jan2016.mp3
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Electro Zim Fire copyright 2016 Dale E. Parson, Creative Commons 3.0, copy freely with attribution.
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Waveforms
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Live signal processing in the feedback path.
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_________________ When the stream is deep
my wild little dog frolics,
when shallow, she drinks.
Joined: Jul 07, 2007 Posts: 2081 Location: Berks County, PA
Audio files: 90
Posted: Fri Feb 19, 2016 8:37 pm Post subject:
Subject description: more zim
A few more papers, plus an excerpt from another playing around session.
The Burns & Burtner paper's abstract starts out:
Quote:
Compositional and performance experience with a wide variety of audio feedback systems suggests a number of traits common to feedback processes. These systems share not only certain sonic qualities, but also offer highly linked relationships between pitch, timbre, amplitude and time characteristics. These unconventional parameterizations, along with the often unpredictable response of feedback systems to control and input, lead almost necessarily to an improvisational approach in composition and performance.
I am finding that last sentence to be very much the case. The best sessions come with very little planning, although I guess with much preparation in learning my way around the instrument.
I am amazed at what I can put into the feedback loop without killing the signal. Comes with practice, I guess.
ChutesAndLadders2016.mp3
Description:
Chutes & Ladders, copyright 2016 Dale E. Parson, Creative Commons 3.0, copy freely with attribution.
Joined: Jul 07, 2007 Posts: 2081 Location: Berks County, PA
Audio files: 90
Posted: Sat Apr 02, 2016 9:34 pm Post subject:
Steve Mokris posted videos of the March 19 planetarium performances here https://vimeo.com/channels/cse2016 , including the above ZIM+JAWS+Processing visualization piece. _________________ When the stream is deep
my wild little dog frolics,
when shallow, she drinks.
Joined: Jul 07, 2007 Posts: 2081 Location: Berks County, PA
Audio files: 90
Posted: Thu Apr 21, 2016 7:59 pm Post subject:
Only one of these posted excerpts has to do with ZIM, but a friend and I at school are discussing spoken word. I had tentatively decided to edit just the spoken word portion of 2007's Ordinary Machinery, which I performed live at Electro-Music 2008 in Kingsport. When I looked at this 2007 EM thread, I realized that OM had been posted on Virb, that account long since dead. I've had an mp3 of the full piece posted on my university site for some years.
The ZIM piece These Voices is an excerpt from a practice session in August 2012 for EM 2012 the following month, posted in full here on EM. Unlike OM, I could not bear to cut away all the pre-spoken part of TV, because it is all lovely processed ZIM.
Sierra Parson wrote and performed the spoken word parts for both 2007's Ordinary Machinery and 2012's These Voices. Jeremy Parson plays bass on the former & recorded it.
OM20072016Parson.mp3
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Ordinary Machinery, 2007, spoken word part + virtual machinery.
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TV20122016Parson.mp3
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These Voices, ZIM + spoken word part + surpise voices + sampled virtual voices, 2012.
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_________________ When the stream is deep
my wild little dog frolics,
when shallow, she drinks.
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