Noise Reap Bermuda
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    Recently I have really been enjoying the sound of this simple inexpensive triangle core oscillator and thought I would make a version for Audulus. The Noise Reap version has a "SELF-MOD" that can slightly change the waveshape, but it's a velocity sensitive effect so I have opted for the more achievable standard shape knob. The 1/oct input takes the frequency knob setting as it's reference pitch, so you can use the oscillator as pitch-tracking modulation source. If you just want it to be in tune, set the frequency knob's value to .632455.

    Edit: 7-23-2017 updated sine output to more closely resemble zener diode distortion.
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    bahama 1.2.audulus
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  • OK, you've convinced me. I love the graphics. I assume you're importing the text as curves. I couldn't get plain text to work with SVG. (the oscillator is pretty cool too!). If you wanted something velocity sensitive you can alway modulate the shape knob with a midi gate signal.
  • Yep, I had to convert to curves, which is why the holes in the "B" and "R," etc., are filled in. I tried to add the no fill curves to create negative space, but I'm afraid that my illustrator skills are a bit rusty at this point, so I just went with the flow and accepted the aesthetic.

    I should have put a link to the original module, Bermuda in the first post, but I'll do that here: http://noisereap.com/?product=bermuda

    You can see where the design comes from and that page also has video reference for the shape modulation. You can really see in the sine wave video that they don't create pure sine waves but rather sculpt the triangle, so that's how I proceed with Bahama. It's a subtle sound, but sometimes that's what you want.
  • I didn't really notice the missing "holes" in Bahama. I think you could make black shapes in Illustrator to fill them in, but I don't believe any sort of transparency will work. I was thinking you could lasso the hole and then create a new curve and fill it with black (or whatever your background is). I envy you guys that actually have modular hardware, I got into Audulus mostly because I always wanted a modular but could never justify the price. I remember when the Moog first came out, I was just blown away. (really old rock musician retired from a day gig as a computer engineer in case you're wondering)
  • @stschoen You're retired? That's the perfect time to blow all your savings on modules! ;)

    I resisted the urge to go actual modular for a long time (I had some moogerfoogers and synths before) until I was hit by a car while out riding my bike. I figured that since life was short, I should do that thing I always wanted to do but could never justify. I've really enjoyed it so far, but I am noticeably poorer as a result. Fortunately a bermuda oscillator s like $65, which is cheap any way you look at it. It may be missing a saw wave and sync input, but it sounds nice and is an extra oscillator. All the same, I can definitely respect your point of view, not acquiring stuff is all sorts of good.
  • I've got too much stuff already, but I'm always open to more (assuming I can find the space). That's an insanely low price for a module at least compared to the others I've seen. My epiphany came when I was diagnosed with Hodgkins Lymphoma. Fortunately it's very treatable and I think I'm past it now, but I know exactly what you mean. Music has always been my passion and I have to admit that I've indulged myself since I realized that you're only here for a short time. Amazing how your perspective changes.
  • Love this!!
  • After carefully looking at and listening to the Bermuda sine wave, I made an adjustment to the triangle to sine modeling. Turns out the spline node object is pretty ideal to model diode nonlinearity circuits.

    The original post has been updated.
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    TRI to SINE.audulus
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  • I'm really enjoying all the work you're putting into these recreations, the SVGs too!
    I was experimenting with imitating the sine distortion with the tanh expression.
    Tan on the R channel, spline on the left.
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  • Very nice! I think the Tan looks/sounds looks about right too but with less angles. It could be an improvement :)
  • I was thinking of Rob Hordijk's explanation of the algorithm he uses for his ‘curved’ (parabol) waveform – I never got that totally figured out, but the tan expression seems to achieve a similar result. (See from around 10m28s.)

    https://youtu.be/6pNJYnlOwg8?t=10m28s
  • By the way, if you open up the output module in the patch I posted, you'll notice that I've disconnected the DC Blocker as it was changing the shape of the basic waveforms from the oscillator when looking at them in the scope (somewhat like a filter would). It took me a while to figure out that that was the cause of it! I still don't understand exactly why.
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  • @Rudiger - the DC blocker filters out low frequency oscillations (below 20Hz) and static DC offset. It's used to prevent your speakers from being constantly pushed out or pulled in, which can distort and damage them. Sometimes it might affect the way audio behaves too - say, if you have audio coming out of a z-1 filter (which can apply an offset), and then going into a distortion or clipper circuit, it might distort unpredictably as you change the filter's cutoff or Q.
  • @Rudiger What oscilloscope app is that? It looks really nice and you can use audiobus! I love that video series with Rob Hordijk. His designs always ride the border between conventional and unique with an emphasis on classic 1950's sci-fi.
  • @biminiroad Ok, thanks, that explains it. I had the frequency on Robert's Bahama set to around 2 hz (if I remember correctly) so that I could see the waveforms on the Audulus waveform nodes as well. Just checked with 220 hz and all is as expected. Good to know that that's what it's doing below 20 hz!
  • @Rudiger - if you want a scope that can read audio, check this out one (attached)
    Scope Demo.audulus
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  • @RobertSyrett It's part of MC Studio by Sascha Bienert
    https://appsto.re/dk/YMj71.i
    Also available on its own as a standalone app.
    The audiobus integration is great, the only thing is that it isn't available in spilt screen mode. Fortunately Audulus is, so my workaround is open MC studio and then slide Audulus over to make changes/watch adjustments.
  • @Rudiger Awesome, I just downloaded the suite. In the video you posted, Rob Hordijk was showing his waveshaper which is something of an obsession for me. I thought I would take a shot at emulating it, to look at on the oscilloscope :) Watching waves fold on the oscilloscope while listening to them is kind of a guilty pleasure for me.
    Diode Wavefolder.audulus
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  • The scope is a bit of a kludge. I basically sampled the waveform with a sample and hold driven by a phasor to slow it down enough for the waveform display. Kind of a reverse FM. It makes the display a bit noisy. I should probably run it through a LPF to remove some of the noise. It might also be possible to use the zero-crossing node and sync to eliminate the need to provide the frequency in.
  • @biminiroad Thanks. I had already come across the scope – useful, but I still enjoy the extra detail of the external app for certain things.
  • @RoberSyrett Thanks for the wavefolder patch, and yes, watching waveforms is its own special kind of pleasure :-)
  • @biminiroad @stschoen A dedicated Audulus oscilloscope node/module would be a great addition.
  • @RobertSyrett Ok, I think I have something approaching Rob Hordijk’s Fluctuation waveform. As I understand it from the video the combined FM/AM signal is an organic result of the double integrator algorithm. I haven't quite figured out how to implement that in Audulus yet, so I've simply coupled regular FM and AM modulation – the only trick being to invert the AM signal so that the highest points of the FM correspond to the lowest points of the AM. Looking that the waveforms in a scope seems to come close to what Rob shows in the video around 16m10s.

    And then one can slowly dial in the waveshaper so that it starts to trigger on the amplitude peaks.

    (BTW I still have the DC coupling disconnected in the output module as it was altering the waveforms slightly even at higher frequencies.)
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  • Looks great! I usually don't use the output module to be candid. I typically will just slap a level node on a speaker node and call it a day. There is something to be said for simplicity. Looking forward to playing around with this on the oscilloscope :)