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Sine wave from Analog synth has extra partials?
Posted: Tue Mar 09, 2010 4:12 am
by ark
If I put an instance of Analog in a MIDI channel and then put an instance of Spectrum after it, I see that when I set Analog to produce a sine wave, what I really get includes lots of partials, with the loudest being the second harmonic at about -45dB from the fundamental.
If, on the other hand, I use Operator, the frequency spectrum I get is much purer.
I am assuming that this is an artifact of Analog's attempt to simulate classic analog synths, flaws and all; but I wonder if anyone else can confirm that I'm not missing something obvious.
Re: Sine wave from Analog synth has extra partials?
Posted: Tue Mar 09, 2010 6:06 am
by funky shit
geekiest. forum post. ever

Re: Sine wave from Analog synth has extra partials?
Posted: Tue Mar 09, 2010 6:19 am
by Homebelly
ark wrote:I wonder if anyone else can confirm that I'm not missing something obvious.
Um???
That your off pink plaid short sleeve shirt doesn't work with your tartan bow tie, or that orange pocket protecter.
I mean, well... i don't want to sound like the fashionista, but corduroy is so not in this year, especially brown.
Re: Sine wave from Analog synth has extra partials?
Posted: Tue Mar 09, 2010 7:36 am
by alex.the.forge
ark wrote:
I am assuming that this is an artifact of Analog's attempt to simulate classic analog synths, flaws and all; .
that would be my guess
Re: Sine wave from Analog synth has extra partials?
Posted: Tue Mar 09, 2010 7:41 am
by COSM
I think its a great question and look forward to a serious answer

Re: Sine wave from Analog synth has extra partials?
Posted: Tue Mar 09, 2010 9:08 am
by Bunky Freaks
serious try

even/odd harmonics are possibly created in the filter saturation or another stage (->analog distortion modeling). if the filter can be bypassed see if it changes anything in the spectrum.
Re: Sine wave from Analog synth has extra partials?
Posted: Tue Mar 09, 2010 9:33 am
by Bagatell
COSM wrote:I think its a great question and look forward to a serious answer

+1
not all of us are throwing samples together to make "product".
Re: Sine wave from Analog synth has extra partials?
Posted: Tue Mar 09, 2010 10:06 am
by swishniak
Bagatell wrote:
not all of us are throwing samples together to make "product".
+1
oh snap
Re: Sine wave from Analog synth has extra partials?
Posted: Tue Mar 09, 2010 1:55 pm
by ciw
funky shit wrote:geekiest. forum post. ever

^^^ No offense but if that's the prevailing attitude then the ableton forum really isn't what it used to be! Asking questions like that has improved my production a lot.
What Bunky Freaks said seems sensible. Although whether or not disabling the filter changes it, doesn't tell us much, there could be a saturation stage elsewhere or it could be in the oscillator waveform.
-45db sounds quiet though. I can't try this right now but can you try hard to get exactly the same sine wave out of both synths, set up a blind a/b test and then tell the difference?
Re: Sine wave from Analog synth has extra partials?
Posted: Tue Mar 09, 2010 2:48 pm
by 3phase
alex.the.forge wrote:ark wrote:
I am assuming that this is an artifact of Analog's attempt to simulate classic analog synths, flaws and all; .
that would be my guess
a sine on a classical analog has no partials..
Re: Sine wave from Analog synth has extra partials?
Posted: Tue Mar 09, 2010 4:06 pm
by noisetonepause
3phase wrote:alex.the.forge wrote:ark wrote:
I am assuming that this is an artifact of Analog's attempt to simulate classic analog synths, flaws and all; .
that would be my guess
a sine on a classical analog has no partials..
Err. Yes it does. You're not going to get a pure sine wave out of analogue circuitry, it's always going to get distorted somewhere. Eh, last I looked at the waveform of the output from an analogue synth, the triangles weren't even triangular, and that's a lot easier to synthesise than a sine.
Re: Sine wave from Analog synth has extra partials?
Posted: Tue Mar 09, 2010 4:10 pm
by funky shit
ciw wrote:funky shit wrote:geekiest. forum post. ever

^^^ No offense but if that's the prevailing attitude then the ableton forum really isn't what it used to be! Asking questions like that has improved my production a lot.
chillax.. im probably the biggest geek in this thread,
but please agknowledge the fact that apart from TD's cable orgasms, this was pretty geeky,
i didnt say it was a bad thing.
Re: Sine wave from Analog synth has extra partials?
Posted: Tue Mar 09, 2010 4:34 pm
by ciw
Ok ok I chill

I don't read enough of this forum to judge but there are certainly similar threads around. I started one elsewhere a while back regarding why a certain commercial tune had a pretty flat spectrum even when only kick and bass were going. (The answer, a hihat on each kick). All important stuff to know. Then there are linear phase eqs, oscillator phase on basslines, and so on, all seemingly technical nitpickery but actually having an audible effect.
Re: Sine wave from Analog synth has extra partials?
Posted: Tue Mar 09, 2010 4:40 pm
by 3phase
noisetonepause wrote:
Err. Yes it does. You're not going to get a pure sine wave out of analogue circuitry, it's always going to get distorted somewhere. Eh, last I looked at the waveform of the output from an analogue synth, the triangles weren't even triangular, and that's a lot easier to synthesise than a sine.
You want to tell me that analog synth cant producer propper sinewaves? some minimal distortion hardly cant be called a partial

Re: Sine wave from Analog synth has extra partials?
Posted: Tue Mar 09, 2010 4:43 pm
by noisetonepause
3phase wrote:You want to tell me that analog synth cant producer propper sinewaves? some minimal distortion hardly cant be called a partial
No, I don't find it at all improbable that an analogue synth attempting to produce a sine wave will have overtones at -45dB. You'll note that OP says he sees it in the spectrogram, not that he heard it.