Sine waves

[_dan]

I've noticed that many of the newer synths with analog components omit sine waves in the oscillators and LFOs. Is there a functional/non-musical explanation for this?

[GuyaGuy]

Sine waves contain only the fundamental pitch. Waves like a square or a sawtooth contain harmonics in addition to the fundamental. To get a sine wave (or pretty darn close) you can use the filter to remove the harmonics, leaving you just with the fundamental.

But I do find LFOs nice for LFOs--very fluid and not as on/off as a triangle, square, or saw.

[JayEm]

There's a q&a with oberheim on YouTube and someone asked a similar question. He basically stated that they are both boring and more difficult to produce properly than saw or square.

[8bit9bot]

i agree they're mostly boring - the CS series synths allow you to do some nice high pass filtering w/ reso... the mixer section allows you to add back the fundamental by allowing a sine wave to bypass the filter and go straight to the mixer- i like this... its similar to some FM synthesis sounds... other than that i've never really cared for sine waves - on LFOs they sound almost the same as triangle waves

[moremagic]

a triangle wave is darn close and really easy to implement in a regular oscillator circuit, either one that starts producing the triangle wave or starting with a sawtooth wave.
an actual sine wave oscillator is effectively a resonant filter -- it doesnt really work out at making other waveshapes except for square and pulse waves as the pulse is generated from a sine wave just the same as from any other. thus you end up with the one lfo on the sh-3 that does sawtooth waves and the other that does the sine and square, for instance

[_dan]

That is very interesting, and thank you all for responding. Guya, I enjoy the sine wave LFO as well. Can anyone reccomend a good book that discusses the evolution of synthesizers from a technical/engineers perspective? (To be clear, I'm not in any way complaining about the currently available tech, and I have plenty of ways to get the sine wave when I need it.)

[Shanesaw]

You may or may not know about Fouier Synthesis but basically, all complex sounds can be broken down into an infinite series of "partials". These partials in turn, are all constructed of sine waves of different phases, amplitudes and pitches!
Here's a quick read: Explanation of Fourier synthesis

I used to have a freeware Fourier synth but I can't remember it's name.

I guess for your average synth user, sine waves could be pretty boring though as Guyaguy pointed out, they are only fundamental tones.

[commodorejohn]

You may or may not know about Fouier Synthesis but basically, all complex sounds can be broken down into an infinite series of "partials". These partials in turn, are all constructed of sine waves of different phases, amplitudes and pitches!
Here's a quick read: Explanation of Fourier synthesis

I used to have a freeware Fourier synth but I can't remember it's name.

I guess for your average synth user, sine waves could be pretty boring though as Guyaguy pointed out, they are only fundamental tones.

Yeah, there is that (and there's a number of additive synthesizers out there operating on that principle - the Kawai K5000 and the Digital Keyboards Synergy, for example.) But this was more discussing sine waves in a subtractive synthesizer, where they are significantly less useful (all you can really do with them is reinforce a particular harmonic, or add one not present in the series of whatever other waveforms you've got going.)

[pmh]

I would've thought, like many of the other thread contributors, that they give such a bland sound only the purists would use them.

That said, this isn't really a reason to leave them out, as I doubt any significant cost savings are made by exclusion.

Shame really, as it was sort of tradition: Sine, Sawtooth, Triangular, Square, Square with different mark space ratio.

Kind regards,



Phil

[commodorejohn]

That said, this isn't really a reason to leave them out, as I doubt any significant cost savings are made by exclusion.

You think? I was under the impression that sine generation typically requires an entirely different kind of oscillator, at which point you're adding more hardware just to have something you can accomplish by filtering down another waveform (or near-enough approximate with a triangle.)

[pmh]

That said, this isn't really a reason to leave them out, as I doubt any significant cost savings are made by exclusion.

You think? I was under the impression that sine generation typically requires an entirely different kind of oscillator, at which point you're adding more hardware just to have something you can accomplish by filtering down another waveform (or near-enough approximate with a triangle.)

No doubt it would be a separate oscillator, but hardly complex in its construction.

As you are no doubt aware, there are many ways of generating a sine wave, and this can be achieved with some quite simple circuitry.

For a company that manufactures electronic hardware, the component cost would be very small, and the space on the PCB minimal.

Just my opinion of course.

Kind regards,



Phil

[Automatic Gainsay]

The sine in both the Yamaha CS-50 and the one in the Sub Oscillator in the Arturia MiniBrute are absolutely wonderful, and very useful.

I am one of those damned purists, but I actually like the sine a lot. I use it far more than triangle... and I'd rather not waste the filter on removing a few harmonics from the triangle.

[Augment]

Not sure that you'd need a dedicated oscillator just to produce a sine wave. Any oscillator should be capable of producing a sine wave. It's likely that calibrating one for it falls into the "more effort than its worth" category, at least as far as traditional analog/subtractive synthesis goes. Plenty -if not most- modular oscillators feature sine waves due to their secondary use as LFOs/modulation sources.

Analog hardware wise, the only thing I have that includes sine waves is the Moogerfooger Ring Modulator; the LFO is selectable between sine and square, and the Carrier oscillator is (I presume) a sine as well. Both have individual output jacks: you can run the sine LFO out to a CV input for modulation, and you can also control the Carrier oscillator frequency via CV and run just the Carrier output for pure analog sine goodness. Why haven't I thought of doing this before?!

[moremagic]

Analog hardware wise, the only thing I have that includes sine waves is the Moogerfooger Ring Modulator; the LFO is selectable between sine and square, and the Carrier oscillator is (I presume) a sine as well. Both have individual output jacks: you can run the sine LFO out to a CV input for modulation, and you can also control the Carrier oscillator frequency via CV and run just the Carrier output for pure analog sine goodness. Why haven't I thought of doing this before?!

actually, no, it isnt. they used a triangle in the lfo and just printed a sine on the panel cuz it looks cooler.

[calaverasgrande]

how are pure sine waves boring?
I like the tone of a pair of detuned sine oscs a lot!
Sometimes you kind of do want an osc with not a lot of harmonic content, and you don't want to (or can't) waste a filter on smoothing out a triangle or square.
To my ears those aren't always equivalent anyway since most filters have side effects that aren't always desirable.
As far as LFOs, there is certainly a difference between triangle and sine. Though it is really only evident at slow speeds and in situations that 'snowball' when the LFO accelerates and decelerates. Delay based effects are the best example that comes to mind.