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Stream Operator
Joined: Oct 13, 2007 Posts: 6221 Location: near Austin, Tx, USA
Audio files: 267
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Posted: Sun May 12, 2019 4:59 am Post subject:
Oscillators and Related Circuitry Subject description: A Project Thread |
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Let's play with oscillators! I was daydreaming about oscillators, logic, and assorted networks when it occurred that this topic would make a good electro-music.com project thread. So here we are.
I've purchased some parts and some more that fell through the cracks are on the way. The list includes breadboards, opamps, lamps, jumper wires and assorted "breadboard friendly" parts from Adafruit (pots, jacks, battery holders, etc.). Which, BTW, those breadboard friendly parts are golden because the tiresome task of soldering leads onto parts for breadboard use all but disappear.
So anyway, the plan is to make oscillators and hook them up in interesting ways, then play around interactively to discover something worth building. In other words, the usual interesting stuff.
So here we are at the beginning of yet another project thread and I'd just like to leave you with one thought. When you post to a project thread it motivate me. Probably the single biggest project killer is lack of interaction. So if you have a free moment, I'd love to read whatever strikes your fancy.
Here's to good times!
Les _________________ "Let's make noise for peace." - Kijjaz Last edited by Inventor on Sat Aug 31, 2019 11:17 am; edited 1 time in total |
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Grumble
Joined: Nov 23, 2015 Posts: 1294 Location: Netherlands
Audio files: 30
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Inventor
Stream Operator
Joined: Oct 13, 2007 Posts: 6221 Location: near Austin, Tx, USA
Audio files: 267
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Posted: Sun May 12, 2019 4:33 pm Post subject:
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Sure Grumble, it's great to see the gear you have. You could chain those oscillators together to test out some ideas.
What I am doing is circuit level, where it's possible to evolve it into a pedal or enclosed PCB device. Maybe even a modular board.
I am sleepy so I'll write more later.
Les _________________ "Let's make noise for peace." - Kijjaz |
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RingMad
Joined: Jan 15, 2011 Posts: 427 Location: Montreal, Canada
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Posted: Mon May 13, 2019 10:41 am Post subject:
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Nice to see you again, Les.
Could you elaborate on what you envision? How would nets be connected together?
As for chains or loops, the first circuit I put in a box was based on the one in Nicolas Collins' book "Handmade Electronic Music" (the book that started me on this electronics adventure), wherein he proposed four NAND gate oscillators, each one gating the next one (and the last splitting into the output as well as a feedback pot going back to the first one).
Those of course are simply plugged directly.
Nets would need to involve something more elaborate, right? Resistor or diode mixers? Or maybe the interference or whatever the appropriate technical term is for when signals go backwards, affecting a circuit would actually give interesting results?
.:james:. |
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blue hell
Site Admin
Joined: Apr 03, 2004 Posts: 24083 Location: The Netherlands, Enschede
Audio files: 278
G2 patch files: 320
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Posted: Mon May 13, 2019 1:42 pm Post subject:
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I think delays in the connection paths would make it come alive
Also this made me think of a performance Howard once did, 2003 I t hink it was, in London, for two oscillators ... so a very simple network which was played by turning knobs ... let me see if I can find a link ... yupsa _________________ Jan
also .. could someone please turn down the thermostat a bit.
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RingMad
Joined: Jan 15, 2011 Posts: 427 Location: Montreal, Canada
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Posted: Tue May 14, 2019 12:16 pm Post subject:
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Blue Hell wrote: | a performance Howard once did [...] for two oscillators ... so a very simple network which was played by turning knobs |
Yes! Some very nice sounds in there.
I wonder if it gives anything to connect several pairs of oscillators in the same manner.
I also like the unpredictability. (Although playing a concert with it can be pretty scary... I remember with horror my most disastrous concert, using no-input mixing board).
Delays could be good too, although I admit that I don't know how those would be achieved (except maybe if only dealing with square waves).
Jan/Blue Hell, did you ever reproduce Howard/Mosc's patch on WREN? Would it be possible? Maybe I should finally try WREN.
.:james:. |
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blue hell
Site Admin
Joined: Apr 03, 2004 Posts: 24083 Location: The Netherlands, Enschede
Audio files: 278
G2 patch files: 320
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Posted: Tue May 14, 2019 1:10 pm Post subject:
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RingMad wrote: | Jan/Blue Hell, did you ever reproduce Howard/Mosc's patch on WREN? Would it be possible?
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No, I didn't ... in fact it's the first time now that I've actually looked at the patch .. Wren does not have the phaser module properly .. this could be patched with some delays, lfo's and mixers.
But let me not derail the thread too much _________________ Jan
also .. could someone please turn down the thermostat a bit.
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RingMad
Joined: Jan 15, 2011 Posts: 427 Location: Montreal, Canada
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Posted: Wed May 15, 2019 4:52 am Post subject:
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Blue Hell wrote: | Wren does not have the phaser module properly |
The phaser was just for "stereo-izing" the output, it seems. The heart of the patch is the cross-modulation of the oscillators, and is the part I think most interesting, and possibly applicable to this thread.
Anyway, that's what I want to try first, if I had time... I'm preparing for a solo concert, although... no, no, it's too risky to attempt a set with a hardware version of Mosc's thing.
.:james:. |
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Inventor
Stream Operator
Joined: Oct 13, 2007 Posts: 6221 Location: near Austin, Tx, USA
Audio files: 267
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RingMad
Joined: Jan 15, 2011 Posts: 427 Location: Montreal, Canada
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Posted: Sat May 18, 2019 5:19 am Post subject:
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I'm not sure if I should post this here or in Howard/Mosc's old thread. I built a couple of 555 astable oscillators and cross-modulated them, but I don't get anything like the nice timbres Mosc did.
Specifically, for both oscillators, I took the output at pin3 and split it to its own pin5 as well as the other 555's pin5 (through a capacitor). I also took the output from one and put it into a bandpass filter, and then mixed that with the raw output of the other oscillator. So, I believe this is the essentials of what Mosc did, without the compressor or stereoization stuff. The sounds I was getting never had wild volume fluctuations, so compressing wasn't necessary.
Maybe there's something I'm missing.
.:james:. |
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Inventor
Stream Operator
Joined: Oct 13, 2007 Posts: 6221 Location: near Austin, Tx, USA
Audio files: 267
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Posted: Mon May 20, 2019 8:35 am Post subject:
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Hi James, maybe it's best to back off a little then move forward in steps.
You could connect one oscillator to the output and vary it's control(s) to observe the range of sounds that it normally makes. Then make a chain but do not close it into a loop, noting the changes in sounds that you can make. Finally add a connection to form a loop and see how you like that.
Les _________________ "Let's make noise for peace." - Kijjaz |
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Inventor
Stream Operator
Joined: Oct 13, 2007 Posts: 6221 Location: near Austin, Tx, USA
Audio files: 267
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AlanP
Joined: Mar 11, 2014 Posts: 746 Location: New Zealand
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Posted: Tue May 21, 2019 9:47 pm Post subject:
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Very cool, Les |
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Inventor
Stream Operator
Joined: Oct 13, 2007 Posts: 6221 Location: near Austin, Tx, USA
Audio files: 267
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Posted: Thu May 23, 2019 1:32 am Post subject:
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AlanP wrote: | Very cool, Les |
TY Alan.
I was having some issues with powering the board due to lack of parts in my workshop. No battery holders, no wall power cube jacks, no usb power connectors - all stuff I normally have suddenly missing. So what to do?
Order new parts then look more. So long story short, lots of power parts are on the way. This includes some pleasantries such as a 2.1mm jack in-line power switch, very handy and very safe. Also some panel mount USB power input parts for the final design.
Then I searched more thoroughly, and on top of the refrigerator was a box in a box that had a jack and plug of 2.1mm size! The female one was what the circuit needed so I hooked it up, plugged in a 12VDC transformer found earlier, and and suddenly crisp, loud (loud enough) tone came out of the speaker!
So long story short, problem solved. I played a bit with the frequency knob of the oscillator and was able to get bird calls out of it even! Happy day!
Les _________________ "Let's make noise for peace." - Kijjaz |
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kkissinger
Joined: Mar 28, 2006 Posts: 1356 Location: Kansas City, Mo USA
Audio files: 42
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Posted: Sun May 26, 2019 1:28 pm Post subject:
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Hi Les. Look forward to seeing and hearing your results! _________________ -- Kevin
http://kevinkissinger.com |
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Inventor
Stream Operator
Joined: Oct 13, 2007 Posts: 6221 Location: near Austin, Tx, USA
Audio files: 267
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Posted: Mon May 27, 2019 2:43 am Post subject:
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kkissinger wrote: | Hi Les. Look forward to seeing and hearing your results! |
Hi Kevin, it's great to hear from you! I find myself typing messages and erasing them - well what can you say? How about just "back to the project at hand..."
I have managed now to coax some bird chirps and other typical oscillator sounds from the breadboard circuit that I've been describing. Next I'm planning to add one or more Wien Bridge Oscillators and see what lovely tones I can create with them. I'll have to record some audio!
Les _________________ "Let's make noise for peace." - Kijjaz |
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Stream Operator
Joined: Oct 13, 2007 Posts: 6221 Location: near Austin, Tx, USA
Audio files: 267
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AlanP
Joined: Mar 11, 2014 Posts: 746 Location: New Zealand
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Posted: Mon Jun 24, 2019 11:45 am Post subject:
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is that a neon lamp? I've got some, but not messed around with them yet |
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Inventor
Stream Operator
Joined: Oct 13, 2007 Posts: 6221 Location: near Austin, Tx, USA
Audio files: 267
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Posted: Wed Jun 26, 2019 3:57 am Post subject:
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It's a lamp, yes. I'm not sure if it's neon or incandescent or whatever else a lamp can be. I got it from Digi-Key. I'm not sure if it's the right lamp for the job and some kids claim to have damaged half of my stock of 10 lamps including this one. The kids are pranksters. Grrr but not that much!
This lamp reads 100 Ohms when off. I heard it mentioned that sometimes the lamp glowed and other times it did not glow in this application, dependent on the setup. Or it can glow below the visible threshold in daylight and room lighting.
The way it works is the lamp has a positive temperature coefficient meaning that when it heats up it gets higher in resistance. So what happens is the amp starts out with harmonics in it's spectrum then the lamp warms up from all the signal applied to it and this causes the gain of the lamp to lower then the reverse happens, etc. (or the other way around, anyway it stabilizes). This creates a clean sine wave.
When I play with it I see signs of this happening by tuning the lamp so that harmonics exist up and down the AM dial. Then when I tune the feedback resistor (I make it a 10k Ohm pot) I notice the effect. In no case do I not notice the feedback. I think this is because the trimmer pots I am using are 10k Ohms and the resistor is 100 Ohms, so I plan to use a smaller resistor parallel with the pot to get more sensitivity. That or get a 1k Ohm or 100 Ohm pot.
Anyway, it's really fun to play with and the goal is worth the effort. Stay tuned!
Les _________________ "Let's make noise for peace." - Kijjaz |
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Stream Operator
Joined: Oct 13, 2007 Posts: 6221 Location: near Austin, Tx, USA
Audio files: 267
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Posted: Wed Jun 26, 2019 4:51 am Post subject:
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"Oh man, he's writing a book!" Well, just skim it - it's not all that much.
I just wanted to make note of the purpose here and good intentions at this point. I made an LM386 circuit with a speaker and it worked pretty well. I could adjust amplitude and hear it well. It required lots of breadboard space and a big rat's nest of wires (I used jumpers instead of the neat freak technique). This worked out OK.
Then we have the simple opamp voltage follower driving a 3.5mm or 1/2 inch jack (or both for widest possible compatibility). That's OK too.
Then I got to thinking and it occurred to me that If I used an AM/FM radio as the output device, then I get hearing quality output from the board into speaker(s), headphone jack output also, and all manner of adjustments if purchased such as filtering, on/off button, volume control, etc. This I called the Mr. Microphone approach after the early 1980's product.
So basically I'm planning to try the Mr. Microphone approach! This is good for the final circuit and also for test and design because it should be easy to tap a signal on the board with a voltage follower driving some simple circuit adjustment and get both test signals and final output signal as required.
So that's the plan.
Les _________________ "Let's make noise for peace." - Kijjaz |
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Inventor
Stream Operator
Joined: Oct 13, 2007 Posts: 6221 Location: near Austin, Tx, USA
Audio files: 267
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Posted: Thu Jun 27, 2019 1:38 am Post subject:
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I just improved the transmit distance from about a decimeter to a full meter (early tests of me playing around show this). First I would an inductive antenna, then I made calculations for a matching resonant capacitor. The website for calculating the inductance value is here:
https://www.eeweb.com/tools/coil-inductance
I invite you to have a try at the calculations so we can discuss the matching technique in-depth.
Les _________________ "Let's make noise for peace." - Kijjaz |
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Inventor
Stream Operator
Joined: Oct 13, 2007 Posts: 6221 Location: near Austin, Tx, USA
Audio files: 267
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Inventor
Stream Operator
Joined: Oct 13, 2007 Posts: 6221 Location: near Austin, Tx, USA
Audio files: 267
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Posted: Fri Jul 19, 2019 3:41 am Post subject:
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Hey, just a quick update here. I spent a week or two prototyping the new circuits and achieved only very limited response. I was able to transmit very poor but discernible voice from a short distance of about one foot. Also I randomly made a squelcher that worked within the same short distance.
Overall the brief exploration into Wien bridge transmitting was only partially successful. The next time I take a jaunt down this lane I plan to build an audio oscillator first, add vocals next, and radio with some new pampas I've selected. Hopefully things will go better next time.
Les _________________ "Let's make noise for peace." - Kijjaz |
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PHOBoS
Joined: Jan 14, 2010 Posts: 5599 Location: Moon Base
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blue hell
Site Admin
Joined: Apr 03, 2004 Posts: 24083 Location: The Netherlands, Enschede
Audio files: 278
G2 patch files: 320
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Posted: Sun Jul 21, 2019 8:49 am Post subject:
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Maybe not a 'real ground' but things could improve from using a metal plate connected to the circuit ground. A guy at work recently stressed on using ground planes ... sooo ... anyways .. I found http://www.csgnetwork.com/antennagpcalc.html when googling for: minimum ground plane size _________________ Jan
also .. could someone please turn down the thermostat a bit.
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