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Emu XL-7 & MP-7 User's Group

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Thread

PWM

PWM

2003-11-10 by Christoph Kluxen

Hi,

read something about PWM, today, how can I invert a wave? By samplestart?
Thanx,
christoph


Faking PWM
A good way to get PWM with static sampled waves is to sum a saw and an
inverted detuned copy of 
itself...change the detune and you will change the PWM rate.
- Aeo

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Re: PWM

2003-11-11 by robotchas

The XL7 doesn't have sample reverse, which would effectively 
invert the waveform, so to do this as described you'd need two 
different sawtooth samples, one rising and the other 
descending. I haven't looked at the XL samples on an 
oscilloscope (yet) so I don't know if the saws are all in the same 
direction or not (the Morpheus had at least one "backwards" 
saw, but it also had sample reverse so this wasn't needed). If 
someone has an oscilloscope (hardware or software) handy it 
might be interesting to look at all the saw waves and see how 
their shapes differ.

However, just detuning two saws will give you much the same 
effect. It won't look like PWM on a scope, but it should sound 
pretty close.


--- In xl7@yahoogroups.com, "Christoph Kluxen" <pocketd@g...> 
wrote:
> Hi,
> 
> read something about PWM, today, how can I invert a wave? By 
samplestart?
> Thanx,
> christoph
> 
> 
> Faking PWM
> A good way to get PWM with static sampled waves is to sum a 
saw and an
> inverted detuned copy of 
> itself...change the detune and you will change the PWM rate.
> - Aeo
> 
> -- 
> NEU FÜR ALLE - GMX MediaCenter - für Fotos, Musik, 
Dateien...
> Fotoalbum, File Sharing, MMS, Multimedia-Gruß, GMX 
FotoService
Show quoted textHide quoted text
> 
> Jetzt kostenlos anmelden unter http://www.gmx.net
> 
> +++ GMX - die erste Adresse für Mail, Message, More! +++
> 
> [Non-text portions of this message have been removed]

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