I never did think of any great ideas (which would fit on 5 x 6 holes piece of stripboard), but it did start me playing with PUT oscillators, as you only need a single PUT to make one. What I did eventually produce (only on the breadboard at the moment) was the circuit below. Because the PUT oscillators produce very narrow spikes, the sound is a bit whiny and rather cat-like. To enhance the cattiness, I mixed the output of two PUT oscillators and passed the output into a twin T filter. The frequencies of all 3 parts are controlled by LDRs, so by waving your hands over it, you can get quite annoyingly accurate cat-like sounds. The two pots (actually presets on the breadboard) are only there for fine tuning and are not strictly necessary. I built it for a 12V supply, but it does work on a 9V battery.
I've put it here just out of interest, as it may (or may not) inspire someone to come up with a more musical effect.
Gary
P.S. I know it's not strictly a lunetta, but you could use CMOS oscillators in place of the PUTs, if you wanted to (but would it be as catty?).
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Joined: Nov 10, 2011 Posts: 878 Location: Lancashire, England
Audio files: 14
Posted: Fri Dec 07, 2012 11:44 am Post subject:
I've turned it off ... BUT I CAN STILL HEAR IT! AAAAH!
P.S. nice circuit, it would be good to learn more about thyristors (that is what PUT stands for isnt it?) but I don't think it's lunetta! It's too analogue! _________________ As a mad scientist I am ruled by the dictum of science: "I could be wrong about this but lets find out"
It's a Programmable Unijunction Transistor, but yes, it's very similar in structure to a thyristor, with 4 layers P-N-P-N. They were often used in thyristor/triac circuits as a trigger generator (instead of a diac). Yes, I know it's very analogue, so not a lunetta - sorry!
I also apologise in advance for any nightmares suffered after listening to it...
Joined: Nov 10, 2011 Posts: 878 Location: Lancashire, England
Audio files: 14
Posted: Sat Dec 08, 2012 1:10 am Post subject:
analog_backlash wrote:
Yes, I know it's very analogue, so not a lunetta - sorry!
Don't worry about it, it's still got that lo-fi lunetta sound but lunettas are at thier core, logic/digital devices.
It's definately on my "future experiments" list too thanks for the info aswell. _________________ As a mad scientist I am ruled by the dictum of science: "I could be wrong about this but lets find out"
Joined: Nov 10, 2011 Posts: 878 Location: Lancashire, England
Audio files: 14
Posted: Sat Dec 08, 2012 9:16 am Post subject:
richardc64 wrote:
Is it wrong or just weird that my reaction was tears of laughter?
I knew it wouldn't be long before that sound drove someone insane _________________ As a mad scientist I am ruled by the dictum of science: "I could be wrong about this but lets find out"
I knew it wouldn't be long before that sound drove someone insane
Ah, but what beautiful insanity!
Last night I listened to my tea candle tea box for 30 minutes and it's pretty interesting as one pays attention to different patterns at different times. Well, to me it feels quite random and I don't detect the patterns really. Auditory hallucinations?
Joined: Jan 14, 2010 Posts: 5567 Location: Moon Base
Audio files: 705
Posted: Sat Dec 08, 2012 11:21 am Post subject:
allready found a nice image to use as a front for a for double (stereo ?) version
maybe I'll just have to make a special bonus xmas order, I don't have anything else to build anyway,..
RingMad wrote:
Last night I listened to my tea candle tea box for 30 minutes..
I've been out most of the day, so I've only just read the comments. I didn't really expect it to arouse such interest Thanks for the replies. Selected comments:
Taylor wrote:
That is beautifully irritating.
richardc64 wrote:
Is it wrong or just weird that my reaction was tears of laughter?
They're great reviews! I must quote them in the future.
tony void wrote:
LOL! I so want to build like 10 of these and do a show at one of the local "noise venues"
Are you sure that's a wise idea? I cannot be held responsible for the consequences.
PHOBoS wrote:
I love it!
now combine it with RingMad's teacandle noise box: have the LED's control the LDR's
I can't wait to hear the results of that combination.
PHOBoS wrote:
(wish you posted it last week,. then I could have ordered some of those 2N6028's )
Sorry, but I'm not Nostradamus . I kinda like using weird components, but the downside is that not everyone will have them at hand. Also, they're the sort of component that might end up obsolete eventually.
RingMad wrote:
JingleJoe wrote:
I knew it wouldn't be long before that sound drove someone insane
Ah, but what beautiful insanity!
I am a sufferer from beautiful insanity. Please give generously.
Yes, I see what you mean about the track you posted. I hadn't heard this before.
I was thinking about adding some kind of amplitude control myself, as there's currently no way to shut the [expletives deleted] up. A vactrol VCA seems like a good idea.
that's a great sound! i love the close tuning - to me it evokes a kind of semi drunk balkan-ish musical idiom. will be interesting to see what kind of housing you come up with. _________________ http://soundcloud.com/douglasmseidel
that's a great sound! i love the close tuning - to me it evokes a kind of semi drunk balkan-ish musical idiom. will be interesting to see what kind of housing you come up with.
Thanks for that. I like the description - it makes it sound far more serious than I'd originally intended! I haven't thought about the housing yet. It depends somewhat on how much I refine it (e.g. if I add PHOBoS' ideas).
nathanxl wrote:
richardc64 wrote:
Is it wrong or just weird that my reaction was tears of laughter?
+1, uncontrollable
In these less than happy times, I am glad that I've brought some laughter into the World
Joined: Jan 14, 2010 Posts: 5567 Location: Moon Base
Audio files: 705
Posted: Mon Dec 31, 2012 11:47 am Post subject:
doing some tests with the circuit right now (might update along the way).
first I hooked the output of 1 oscillator up to my scope and as I expected by the sound it makes, it's a really narrow pulsewave.
I have to turn the intensity of my scope up to full to even see it else it just looks like a flatline. This does mean that you could
probably make it with some cmos chips, a diode in the feedback line of an oscillator should do the trick I think.
Something I noticed was that the oscillators have a tendency to lock on to eachother, can be nice but having them just out of
sync creates those nice phasing effects. The only way I could see the lock happening was either through the power rails
or because they are mixed together. I tried some extra caps in the power rails but that didn't have any effect so I changed
the circuit a bit by adding a second 100K resistor. So instead of tying the output caps of each oscillator together to one 100K
resistor,. they now both have their own resistor and those are tied together. No more locking
I have to turn the intensity of my scope up to full to even see it else it just looks like a flatline. This does mean that you could
probably make it with some cmos chips, a diode in the feedback line of an oscillator should do the trick I think.
Yes, I had problems capturing the short pulses on my scope as well. I also thought that you could use CMOS oscillators to do the same job, but as I said, the circuit started as an attempt at Buzby's tiny stripboard challenge, hence the PUTs. I bought some tea candles on the internet and I got a very similar result to your "Candle Cats", but I hadn't recorded it yet.
PHOBoS wrote:
Something I noticed was that the oscillators have a tendency to lock on to each other, can be nice but having them just out of
sync creates those nice phasing effects. The only way I could see the lock happening was either through the power rails or because they are mixed together. I tried some extra caps in the power rails but that didn't have any effect so I changed the circuit a bit by adding a second 100K resistor. So instead of tying the output caps of each oscillator together to one 100K
resistor,. they now both have their own resistor and those are tied together. No more locking
editi:
added some 10K pots in series with the 10nF caps, this turns the narrow pulse into a sort of saw wave, which makes it a bit less harsh sounding. (filter does this too off course)
I hadn't noticed the locking problem - I'll have to have a go at those changes you have suggested.
I haven't done much over Christmas and the New Year, due to the usual round of "enforced merriment" (bah, humbug etc).
Having acquired some PUT's and wanting to try this out before embarking on another box build, I shot a short video with the scope in the background, even though it doesn't add anything to the sounds already offered in this thread.
I made the circuit according to the schematic (using slightly different resistances since I didn't always have the exact values), plus the changes suggested by PHOBoS.
Having only really made oscillators from CMOS chips, I don't really understand how this circuit works. I blindly swapped a few caps to see what happens, but the values in the schematic seem to be the best.
Having acquired some PUT's and wanting to try this out before embarking on another box build, I shot a short video with the scope in the background, even though it doesn't add anything to the sounds already offered in this thread.
What it does add to this thread is that thought that I must get a proper oscilloscope one day! It is really difficult to get my PC scope to show anything really useful with those narrow pulses (perhaps I just haven't learned how to use it properly yet).
RingMad wrote:
Having only really made oscillators from CMOS chips, I don't really understand how this circuit works. I blindly swapped a few caps to see what happens, but the values in the schematic seem to be the best.
I knew very little about PUTs myself. I had come across them in SCR/Triac circuits and I knew that you could make an oscillator with just one of them. My "inspiration" was looking at this article:
The basic PUT oscillator that I based the circuit on is near the bottom of the page. I'd like to say that my approach was deeply scientific, but in fact, I kind of did the same as you, swapping components to see which worked best (or at all - sometimes it just stops oscillating).
Joined: Jan 14, 2010 Posts: 5567 Location: Moon Base
Audio files: 705
Posted: Tue Jan 01, 2013 6:11 pm Post subject:
a video, nice
RingMad wrote:
. I blindly swapped a few caps to see what happens, but the values in the schematic seem to be the best.
I didn't do much experiments with the oscillators yet (different caps change the frequency of course), did try some
different values on the filter and here I can agree that the values in the schematic seem to be the best. (unless you want a completely different sound).
analog_backlash wrote:
What it does add to this thread is that thought that I must get a proper oscilloscope one day! It is really difficult to get my PC scope to show anything really useful with those narrow pulses (perhaps I just haven't learned how to use it properly yet.
The signal on the scope is the output after the filter, which I wanted to mention is a damped sine,
with a rather small amplitude. But you can now see it yourself in the video
Not sure what I will do with the circuit, probably add some sort of random voltage modulation, a CV in or maybe just leave it simple as it is.
What it does add to this thread is that thought that I must get a proper oscilloscope one day! It is really difficult to get my PC scope to show anything really useful with those narrow pulses (perhaps I just haven't learned how to use it properly yet.
The signal on the scope is the output after the filter, which I wanted to mention is a damped sine, with a rather small amplitude. But you can now see it yourself in the video )
Yes, I realised after posting that this was the post-filtering waveform, which I could see on my PC scope. It was the original PUT pulses that I had trouble capturing (it was past my bedtime... )
PHOBoS wrote:
Not sure what I will do with the circuit, probably add some sort of random voltage modulation, a CV in or maybe just leave it simple as it is.
I do have 25 of those PUT's now
I have about the same number of them - they were one of my impulse buys. I have lots of components that I've bought over the years, thinking "I'll find a use for those one day". If I come up with other circuit ideas using them, I'll let you know.
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