Anti-aliased DIY Oscillators

Tim Kleinert

This patch generates a smooth sawtooth wave via the DPW (differentiated parabolic waveform) method.

Anti-aliased DIY oscillators, at last. Smile

Unfortunately the expo tracking precision problem remains due to the inaccuracy of the LevelScaler module. But at least now there is no tracking resolution problem anymore, as this design uses true modulo counters without generating jitter.

cheers,
t

UPDATE: expanded version offering variable width pulse wave added.

DPW-AA-SawOsc_TK.pch2

Description:

DIY sawtooth oscillator with DPW anti-aliasing

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Filename:

DPW-AA-SawOsc_TK.pch2

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1.65 KB

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DPW-AA-SawPulsTK.pch2

Description:

Expanded DIY oscillator with DPW anti-aliasing, offering saw and pulse wave

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Filename:

DPW-AA-SawPulsTK.pch2

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2.16 KB

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dorremifasol · Posted: Mon Jan 10, 2011 2:37 am Post subject:

Tim, this is very impressive! Thank you for sharing such great patches.

I can't wait for a version using user definable waveforms Smile

WhitePony64 · Posted: Sat Mar 05, 2011 5:01 pm Post subject:

Hi all,

I'm just trying to get my head around all the timbre changing patch components I've been looking at lately.

Would I be correct in saying that these antialiasing oscillators are designed to reduce the disadvantages of using a a digital system with a fixed sample rate, as opposed to one with an infinite analogue spectrum?

Would I also be correct if I said that the purpose of these antialiasing oscillators is different from Rob's Tilt Filter and that to get the warmest/most analogue sound out of a patch I should use both together?

Sorry, I'm just trying to understand it all!

Thanks.

Tim Kleinert · Posted: Sun Mar 06, 2011 9:58 am Post subject:

All stock G2 oscillator modules are already sufficiently anti-aliased. The aliasing problem occurs when rolling your own. This patch shows how to suppress aliasing on a primitive counter circuit DIY sawtooth oscillator using the DPW technique.
It's just an experimental patch that probably isn't of much use to anyone Laughing

, but shows that DIY anti-aliasing of some sorts can be done. I like to dabble around with this kind of seemingly useless Laughing

"low level" stuff, as sometimes you occasionally really do find a real practical use for it later on.
If you are looking for techniques to beef up the G2 sound, check out my "oscillator warmth" circuit. It's sort of a "tilt filter for oscillators".

http://www.electro-music.com/forum/topic-34508.html

WhitePony64 · Posted: Sun Mar 06, 2011 2:52 pm Post subject:

Ohh, I see. Cool, thanks for the reply!